“Tricycle” magazine described the boom of LSD during the 1960s as blowing the generation gap wide open. They described it as “the old were appalled while the young were enthralled.” In his manuscript for Flashbacks Leary wrote, “Some students quit school and pilgrimage eastward to study yoga on the Ganges. Not necessarily a bad development from our point of view but understandably upsetting to parents who did not send their kids to Harvard to become Buddhas” (Fields 1).

LSD stands for Lysergic Acid Diethylamide. The synthetic hallucinogenic drug was discovered by accident in 1938 by Swiss chemist Albert Hoffman. Hoffman was so taken aback by the immediate and profound distortions caused by LSD that he penned his experience immediately after his “trip.”

“I was forced to stop my work in the laboratory… and to go home, as I was seized by a particular restlessness associated with the sensation of mild dizziness. On arriving home, I lay down and sank into a kind of drunkenness which was not unpleasant and which was characterized by extreme activity of imagination. As I lay in a dazed condition with my eyes closed (I experienced daylight as disagreeably bright) there surged upon me an uninterrupted stream of fantastic images of extraordinary plasticity and vividness and accompanied by an intense, kaleidoscope-like play of colours. This condition gradually passed off after about two hours.” (Nevid 328)

LSD affects the user by decreasing the affect of serotonin in the brain. Because serotonin normally acts as a neurotransmitter that inhibits neural activity, a decrease in serotonin causes brain activity to escalate. The resulting increase in brain activity produces major sensory distortions, including changes in color perception and hearing. Users often claim that LSD “expands consciousness and opens new worlds – as if they were looking into some reality beyond the usual reality” (Nevid 328). Leary hypothesized that LSD doesn’t actually alter reality in so much that it allows the user to see reality as it truly exists. This is not terribly different from the Yogacara philosophy branch of Buddhism that discusses how the mind is empty and reality as it is seen is actually an illusion. Leary’s idea that LSD enables users to see reality as it truly exists is similar to what Buddhists call “Thusness” or “Ultimate Reality.” The psychedelic experience is described as being beyond the users in that it cannot be put into language or mental constructs. Leary often opined that that while science had the benefit to develop a specific language used to communicate across the board from one scientist to another, no such set of language exists for the psychedelic experience (Leary 24).

As such, it is often difficult to explain what occurs during an LSD trip. Like Hoffman’s experience after accidentally discovering acid in his laboratory, users typically describe vivid colors and sounds coming in what some have described as “waves”.

The psychedelic experience draws many parallels between sensory deprivation, yoga exercises, disciplined meditation, and many religious or aesthetic ecstasies. Leary theorized that the actual drug does not produce the “transcendent experience”; LSD merely acts as the chemical key to opening the mind (Leary 11).

Leary himself had his first psychedelic experience after tripping acid in Mexico in 1960. His familiarity with Buddhist and Eastern studies began while attending West Point Military Academy in Massachusetts. There, he used his time in punitive isolation to study Eastern texts. Leary said his time at West Point was comparative to studying in a yoga monastery (Unknown Author 1).

As a psychologist and professor at Harvard University, Leary expanded his ideas of the useful nature of LSD. He gave acid to inmate volunteers and found the drug useful in the treatment of alcoholism and schizophrenia. His controversial work was decidedly unpopular with his colleagues and Harvard refused renewal of his contract with the Ivy League university. Leary continued his experiments with psychedelic drugs, including LSD and mescaline. He wrote several books on his studies including High Priest Psychedelic Prayers of the Tao Te Ching, Your Brain is God, and The Politics of Ecstasy

In 1962, Leary, along with Ralph Metzner and Richard Albert, adapted the Bardo Thodol of The Tibetan Book of the Dead to write The Psychedelic Experience The book, which has since been translated into seven languages and sixteen editions, was meant to show the correlation between LSD and The Tibetan Book of the Dead Because the original manual was meant to acquaint a dying person with the liberation of the Clear Light of Reality, Leary said it was easy to recast that theory with the death of the ego during a psychedelic trip. He wrote the manual with the intention “that acid, in conjunction with the manual’s guide, could be used to direct and control awareness in such a way to reach that level of understanding called liberation or enlightenment” (Leary 45). This is comparative to the way many practitioners of Buddhism use mediation in an attempt to reach Nirvana.

Leary actually guided his friend Aldous Huxley through the psychedelic experience

while Huxley was dying of cancer. Years before, Huxley had read parts of The Tibetan

Book of the Dead to his first wife as she was dying of cancer. He repeated the instructions into her ear even after she had stopped breathing, all the while saying, “Let go, let go. Go forward into the light. Let yourself be carried into the light’ (Fields 1).

Huxley had his own experiences with hallucinogenics while participating in experiments with mescaline in Los Angeles in May of 1953. During his experience, Huxley remembered a line from one of D.T. Suzuki’s essays, “What is the Dharma Body of the Buddha?” and said he found the answer: The hedge at the bottom of the hill. “What had previously seemed only a vague pregnant piece of nonsense was no clear as day. Of course, the Dharma Body of the Buddha was at the hedge at the bottom of the garden, he wrote in The Doors of Perception (Fields 1).

Still Huxley remained skeptical about the experience. “I am not so foolish to equate what happens under the influence of mescaline with the realization of the end and ultimate purpose of human life: Enlightenment” (Fields 1). Instead, Huxley chose to call it a “gratuitous grace.”

Leary, on the other hand, saw the psychedelic experience as a life-changing one. He advised readers that the only way to hold onto what they learn during a psychedelic session was to extend those principles to everyday life. This is Leary’s famous, “turn on, tune in and drop out” advocacy.

TURN ON -’The turned on person realizes that s/he is not an isolated, separate social

ego, but rather one transient energy process hooked up with the energy dance around hir” (Leary 86). To turn on, Leary said it was important to not let the psychedelic experience stop even after the LSD has worn off.

TUNE IN – ‘Tune in means to arrange your environment so that it reflects your state of

consciousness, to harness your internal energy to the flow around you” (Leary 86). To tune in, Leary recommends changing your dress and housing to reflect your newly “turned on” point of view.

DROP OUT – “Walk, talk, eat, drink like a joyous forest-dwelling god” (Leary 87).

Leary theorized that if everyone turned on, tuned in, and dropped out, there would be grass growing on Wall-Street in less than one year.

The main thrust of Leary’s argument in applying a book meant for the dying is the loss of the ego during a psychedelic experience. The ego is Leary’s term for self. Without the ego, the user has no sense of self. Leary hypothesized that to reach pure awareness, or enlightenment, the user has to remove themselves from the “game,” referring to the roles, rituals and rules defined by society.

The process begins by the user preparing themseif for an actual session by reading material on the psychedelic experience. Then comes the actual taking of the LSD. LSD is an orally ingested drug, usually blotted onto paper or sugar cubes. The drug begins to take affect 30 to 60 minutes after being ingested. The effects of the LSD depend largely on dosage, and as Leary emphasized, setting.

“Immediate set refers to expectations about the session itself. People naturally tend to impose personal and social perspectives on any new situation. For example, some ill-prepared subjects unconsciously impose a medical model on the experience. They look for symptoms, interpret each new sensation in terms of sickness/health, and, if anxiety develops, demand tranquilizers.” (Leary 58)

Some of the side-effects of ingesting LSD include the following: Nausea Trembling, shaking Clammy coldness-which the Tibetans call water-sinking-into-fire Feelings of body melting Body Pressure-which Tibetans call earth-sinking-into-water

Leary wrote that these physical reactions should be avoided as signs of illness, but rather “the consciousness moving around in the body and the onset of ego loss” (Leary Dudjom Rinpoche, a great yogi scholar, once said, “if you see something horrible, don’t cling to it. If you see something beautiful, don’t cling to it.” This idea of refusing to hold onto anything reinforces the Buddhist perspective of impermanence; That nothing is forever. This idea is reinforced in the original Tibetan Book of the Dead and the idea of “samsara”-the endless cycle of birth and rebirth.

Another researcher of Buddhism and LSD, Terence McKenna, said that the links even go so far as compassion and awareness. McKenna spent 25 years studying the ontological foundations of shamanism and spiritual transformation. In an April 1996 interview with “Tricycle” magazine, McKenna said the psychedelic society easily fit into the notion of Buddhist practices.

“Well, compassion is the central moral teaching of Buddhism and, hopefully, the central moral intuition of the psychedelic experience. So at the ethical level I think these things are mutually reinforcing and very good for each other. Compassion is what we lack. Buddhism preaches compassion. Psychedelics give people the power to overcome habitual behaviors. Compassion is a function of awareness. You cannot attain great awareness without attaining greater compassion, whether you’re attaining this awareness through Buddhist practice or psychedelic experience.” (Hunt-Badiner 1). The “habitual behaviors,” as McKenna described them, are what Leary refers to as the “game”- the system of roles and rules the ego goes through on a daily basis. It is perhaps because of the roles and rituals already so thoroughly reinforced by Leary’s time that his ideas were met with such intense scrutiny and dismay. He was often accused of advocating LSD “for kicks” and thought to be the pied piper of a whole generation hell bent on drug use.

“When I’m accused of promoting the use of LSD for kicks, I wonder what they mean by “kicks.” To me the kick means an ecstatic revelation… In any sane society, the word kick could be the ideal, the ecstasy, it means going beyond, getting out of your mind, confronting God. A confrontation with divinity, your own higher intelligence, is going to change you, and some people don’t want to change.” (Leary 96). Instead, Leary said the aim of taking LSD was to open up the user philosophically, increase intelligence, and increase sensitivity. The idea of being led to a higher state of consciousness has even simpler roots in Buddhist practice as evinced by a story Leary recounts of when he was in prison:

“When I was studying mammalian theology at Folsom prison in 1973, it was my custom, during the clear, blue-sky, desert-hot summer months, to walk barefoot in the prison yard. One day the leader of the Hell’s Angels, his name was James “Fu” Griffin, approached me.

“Hey man,” he said, “how come you walk barefoot in the prison yard? Don’t you know that’s dangerous?” We were the best of friends and his question was solicitous, not hostile. He wanted nothing but the best for me.

“Why is it dangerous?” I asked.

“Well you’re exposed. Like to germs and all. You know all these animals spit on the ground here.”

“Yeah, I know. But here’s how I look at it. When you walk barefoot, like undefended, you are very alert about where you put your feet. I’m more alive, like a wild animal, when I’m barefoot. A And, come to think of it, I believe it would be better if more prisoners here stopped spitting on the yard and joined me walking barefoot.”

“I see what you mean,” said James “Fu” Griffin.

He subsequently got a degree in anthropology from Berkeley and later became a Country-Western promoter in San Francisco.” (Leary 23)

Aside from the obvious Buddhist theme of walking barefoot and being “in tune” with your surroundings, another subtler connection can be found between the previous mentions of the links between the psychedelic experience and Buddhism in terms of awareness and compassion. “If we all stop spitting, we can all use it,” Leary said. What Leary is perhaps really saying is that if everyone had the benefit of seeing reality through the lens of the psychedelic experience, maybe everyone would change the way they live. “If everyone in Manhattan were to “turn on” and “tune in,” grass would grow on First Avenue and tieless, shoeless divinities would dance or roller-skate down the carless streets. Ecological consciousness would emerge within 25 years. Fish would swim in a clear-blue Hudson” (Leary 87).

Unfortunately, society at large reduced Leary’s ideas to a hipster fantasy and never truly took the psychologist seriously. John Perry Barlow, co-founder of the Electric Frontier Foundation, reasoned that “the public terror of LSD is based more on media-propagated superstition than familiarity with its effects on the real world” and that even “regular” citizens who have dropped acid are quick to dismiss the benefits of LSD. LSD promotes manipulating reality, rather than accepting it, Barlow said. “LSD is not illegal because it endangers your sanity. LSD is illegal because it endangers control” (Barlow 1). Even the 25 million Americans who have taken LSD would be somewhat hesitant to admit even taking the drug, let alone contributing any sort of positive change to it.

It is because of this existing hostile environment that the use of LSD continues to be done in secret. Many continue to use acid in secret as a sacrament, much like the earliest Tantric circles in India who transformed such taboo substances such as meat and wine into sacraments (Fields 4). Leary even tried to formalize a religion around the use of LSD for legal purposes, even though he shunned the idea of organized religion all together. He attempted to found the “League for Spiritual Discovery” as a means to legalize the use of LSD in the context of religious purposes. After all, Catholic priests were still afforded the right to use wine as a sacrament during prohibition. The idea never came full-circle.

As such, practitioners who use LSD in the context of furthering spiritual development must do so in secret. They say the benefits of such practices far outweigh any stigma of being seen as a “acid drop-out.”

Said one Buddhist practitioner, Myton J. Stolaroff, “In learning to hold my mind empty, I became aware that other levels of reality would more readily manifest. It was only in absolute stillness that many subtle but extremely valuable nuances of reality appeared. I found this effect to be greatly amplified while under the psychedelic substance. This, in turn, intensified my daily practice” (Fields 4).

It is highly worth mentioning, as Leary often emphasized, that the idea of promoting LSD as a means of reaching spiritual awareness, must be done with utmost care and consideration. All throughout The Psychedelic Experience as well as his other texts, Leary continually reinforced the idea of having a guide and understanding the context of what you were doing.

It could be argued that the children who dropped LSD in the 1960s contributed to a decade of confusion and conflict. It could also be argued that those same children grew up and went on to found such things as the internet and continually build society to the way it is today.

This was not just doing drugs just to do drugs. This was a group of scholars, researchers, and psychologists who thought they found a way to change the world, and if not the world, than at least it’s consciousness.

Works Cited

Barlow, John Perry. “Liberty and LSD.” Tricycle Magazine April. 1996.

Hunt-Badiner, Allan. “Sacred Antidotes, an Interview with Terence McKenna.” Tricycle

Magazine April. 1996.

Fields, Rick. “A High History of Buddhism.” Tricycle Magazine April. 1996. Leary, Timothy. The Politics of Ecstasy Berkeley, California: Ronin Publishing, 1980.

Leary, Timothy. Your Brain is God Berkeley, California: Ronin Publishing, 1988.

Leary, Timothy, Ralph Metzner, and Richard Alpert. The Psychedelic Experience A

Manual Based on the Tibetan Book of the Dead New York, New York: Kensington Publishing, 1964.

Nevid, Jeffrey, Spencer Rathus, and Beverly Greene. Abnormal Psychology in a

Changing World New Jersey: Prentice-Hall, 2000.

Unknown Author, Internet Source. “Timothy Leary, Biography, Beatland.”

http://www.spress.de/beat-generation/

Related

• The “Pure Consciousness Experience”

Therefore, whether or not humans want to admit this commonality with animals and insects, every species is impacted by pheromones. Pheromones affect all the processes vital to the continuation of life on this planet: from helping each species to select its mate, to ensuring females ovulate at the opportune time for procreation, to beginning the birthing process and making certain mothers need to nurse their young as much as the young need to be nursed. If it weren’t for pheromones, human beings may or may not choose a compatible mate and other species may not mate at all. Also, if it were not for pheromones, some species may not feel the need to mate during ovulation, making reproduction more of a game of chance. And, if pheromones didn’t play a part of mother-infant relationships, females of any species other than human beings may not nurse or care for their offspring since there would be no chemical signaler telling them they need to do these things. Pheromones are a modulator of life from birth to death and any change in their interaction with all species would heavily influence mating and reproduction.

References

Beier, K. , Ginez, I. , & Schaller, H. (2004, December 18). Localization of steroidhormone receptors in the apocrine sweat glands of the human axilla.

Histochem Cell Biology, 123, 61-65.

Boschat, C. , Pélofi, C. , Randin, O. , Rappolo, D. , Broillet, M.C. , & Rodriguez, I. , (2005 December). Pheromone detection mediated by a V1r vomeronasal receptor. Nature Neuroscience, 5, 1261-1262.

Buck, L. B. , (2004, November). Olfactory receptors and odor coding in mammals. Nutrition Reviews,62, S184-S188.

Cornwell R. E. , Boothroyd, L. , Burt, D. M. , Feinberg, D. R. , Jones, B. C. , &Little, A.C. , et al. (2004, February 13). Concordant preferences for opposite-sex signals? Human pheromones and facial characteristics. The Royal Society, 635-640.

Del Punta, K. , Leinders-Zufall, T. , Rodriguez, I. , Jukam, D. , Wysocki, C. J. , & Ogawa,S. , et al. (2002, September 5). Deficient pheromone responses in mice lacking a cluster of vomeronasal receptor genes. Nature, 419, 70-75.

Dulac, C. & Torello, T. (2003, July). Molecular detection of pheromone signals in mammals: From genes to behaviour. Nature Reviews, 4, 551-562.

Grammer, K. , Fink, B. , & Neave, N. (2004, August 19). Human pheromones and sexual attraction. European Journal of Obstetrics & Gynecology and Reproductive Biology, 135-142.

Hughes, H. C. (1999). Sensory exotica., Cambridge, Massachusetts: The MIT Press.

Johnson, R. L. (1989). The secret language: Pheromones in the animal world. Minneapolis: Lerner Publications Company.

Keverne, E.B. (2004). Importance of olfactory and vomeronasal systems for male sexual function. Physiology & Behavior, 83, 177-187.

Kien, T. & Storm, D. R. (2004, November). Detection of odorants through the main olfactory epithelium and the vomeronasal organ of mice. Nutrition Reviews, Nov. 2004 Supplement, v.62, n.11. S189-S192.

Kimball, John. (2005, November 1). Pheromones. Retrieved November 21, 2005,from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages

Kodis, M. (1998). Love scents: How your natural pheromones influence your relationships, your mood, and who you love. New York: Penguin Group.

Kohl, J. V. & Francoeur, R.T. (1995). The scent of eros: Mysteries of odor in human sexuality. New York: Continuum Publishing Company.

Pankewich, D. E. , Baum, M. J. , & Cherry, J. A. (2004, October 20). Olfactory sex discrimination persists, whereas the preference for urinary odorants form estrous females disappears in male mice after vomeronasal organ removal. The Journal of Neuroscience, 24, 9451-9457.

Savic, I. , Berglund, H. , & Lindstrum, P. (2005, May 17). Brain response to putative pheromones in homosexual men. PNAS, 102, 7356-7361.

Savic-Berglund, I. (2004, November). Imaging of Olfaction and Gustation. Nutrition Reviews, 62, S205-S207.

Seppa, N. (2005, November 1). Nailing down pheromones in humans. Science News Online. Retrieved November 19, 2005, from http://www.sciencenews.org/pages/sn_arc98/3_14_98/fob1.htm

Stowers, L. , Holy, T.E. , Meister, M. , Dulac, C. , & Koentges, G. (2002, February 25). Loss of sex discrimination and male-male aggression in mice deficient for TRP2. Science, 295, 1493-1500.

Von Campenhausen, H. & Mori, K. (2000, January). Convergence of segregated pheromonal pathways from the accessory olfactory bulb to the cortex in the mouse. European Journal of Neuroscience, 12, 33-46.

Wedekind, C. & Furi, S. (1997). Body odour preferences in men and women: Do they aim for specific MHC combinations or simply heterozygosity? The Royal Society, 1471-1479.

Wysocki, C. & Preti, G. (2004). Facts, fallacies, fears and frustrations with human pheromones. The Anatomical Record, Part A 281A, 1201-1211.

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

Related

• Introduction to Pheromones: The Science of Smell
• Opposite-Sex Attraction: The Science of Smell
• Menstrual Cycle Modulator: The Science of Smell
• Same-Sex Attraction: The Science of Smell
• Mother-Infant Bonding: The Science of Smell
• De-Sexing the Bonobo
• A Sinking Earth

A woman’s menstrual cycle can be altered by the pheromones transmitted by either males or females. This chemical signal can cause her cycle to become synchronized, shortened, or lengthened. The male pheromones which affect females are the primer pheromones. Many studies have been conducted on different mammals to explain the affects pheromones have on female mammal’s menstrual cycles.

What Studies Have Been Done to Prove This?

One study experimented on female boars in which male boar urine was rubbed on the female boar’s snout. This caused her to stand in the mating stance, just as if the male boar was standing near her. (Grammer, Fink, & Neave, 2004)

Research on rodents’ chemical communication systems is the most common in laboratories. Female mice are mammals that are easily influenced by male mice pheromones. (Johnson, 1989) Male mice pheromones can revolutionize female mice since the ovulation of female mice is regulated by the pheromones in male urine. In research, it has been shown that when there is no male present, the female’s estrous cycles are not in synchronization. On the other hand, when the male is present, the females become synchronized. Puberty can also be influenced by the presence of male urine. Female mice will begin their oestrous cycles early if introduced to male mice urine early. Mice can determine the dominant male by the signature odor in the present urine.

How Are Female Humans Influenced by Male Human Pheromones?

Human females are easily influenced by human male pheromones; a woman’s menstrual cycle can be regulated by a man’s pheromones from his perspiration. One example is the research conducted by Cutler. Cutler applied male perspiration to the upper lips of women. Through his research, he came to the conclusion that males can cause a woman’s menstrual cycle to become regular – occurring every 28 days. Cutler also concluded, “The male essence seemed to substitute for regular weekly sex” (Kodis, 1998, p.89). Whether or not a woman ovulates is a direct result of the presence of male pheromones. (Kodis, 1998) In her book, The secret language: Pheromones in the animal world, Rebecca Johnson (1989) states:

Women who are celibate do not ovulate during every menstrual cycle – in fact, they ovulate only about half the time. Women who have contact with men, however, ovulate 90% of the time, and their cycles become more regular. (p. 292)

This is further proof that females’ menstrual cycles are influenced by the pheromones of men.

What about Young Girls’ Menstrual Cycles?

Young girls can also be affected by male pheromones. There was a study conducted by Ellis and Garber to show that young girls start puberty earlier if the father or stepfather is in their everyday lives. Girls from single-mother households started puberty later than the girls with fathers or stepfathers. Male pheromones create early puberty in young girls and regulate mature women’s menstrual cycles. (Grammer et al. , 2004)

How Are Human Females Influenced by Human Female Pheromones?

Pheromones of women can also manipulate other women’s menstrual cycles. Women release two primer pheromones: one prior to ovulation and one after ovulation. The pheromone released prior to ovulation causes the menstrual cycle to speed up the arrival of ovulation in other women while the pheromone released after ovulation causes delay in the arrival of ovulation in otherwomen. A woman’s menstrual cycle can be synchronized with another women’s menstrual cycle by the presence of that woman. Martha McClintock and Kathleen Stern conducted a study that showed that women would synchronize their cycles with the cycles of the other women that they lived with. There were 29 women; nine women donated pheromones and the other 20 were recipients of the pheromones. In this study, gauze were placed in the donor’s armpits to obtain the samples of sweat. Placing alcohol on the gauze pads preserved the sweat samples. These gauze pads were cut into fours and frozen. The samples were then given to the 20 recipients to apply on their upper lips for four months. The recipients received two sets of samples: Oneset of samples for the first two months and the other set of samples for the second two months. (Seppa, 1998) The results were as follows:

Samples taken from donors who were in the pre-ovulation stage shortened a recipient’s monthly cycle by roughly two days. In contrast, samples taken from donors during ovulation delayed the cycles of recipients by about a day and a half. The donors, used as the control group, received an inert dab of alcohol; they showed no changes in cycle. (Seppa, 1998, p.1)

This study shows that women’s menstrual cycles do become synchronized with other women’s menstrual cycles due to pheromone cues.

Another similar study was conducted in 1980, by Russell, Switz, and Thompson. This study used 1 woman donor and 16 recipients. Eight women received the gauze with the pheromone and the alcohol. The other eight women received the gauze with only alcohol. The women dabbed their lips three times a week for four months with the gauze. The 16 recipients were not told which gauze had sweat on them. The results to this experiment are as follows: eight women became synchronized with the donor and the other eight women still had random menstrual cycles. (Johnson, 1989)

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

Related

• Introduction to Pheromones: The Science of Smell
• Opposite-Sex Attraction: The Science of Smell
• Conclusion: The Science of Smell
• Mother-Infant Bonding: The Science of Smell
• Same-Sex Attraction: The Science of Smell
• A Means to an End
• Gender Roles and the Media

The bond between a mother and her child are much deeper than just emotional heart strings. Pheromones are exchanged in the womb, through breastfeeding, and through other means of physical contact which create a lifelong bond between mothers and their children. Both humans and nonhumans use pheromones as a means of nonverbal communication and maternal ties.

Pheromones also serve as identifiers. Mothers and children can recognize each other by the pheromones each emits.

Fawns use these pheromones to identify their mothers among the female deer in the herd. A fawn may sniff the tarsal glands (located on the insides of the knees of the rear legs) of a number of females before finding the correct one. (Johnson, 1989, p.27)

The pheromones that allow these fawns to recognize their mothers are the chemical make up that they learn while still nestled in their mothers’ womb.

Where Does the Bond Begin?

Pheromones begin their mother-infant connection before the baby is ever born. While children are in the womb, they begin recognizing their mother’s pheromones:

While hugged in the cozy, wet warmth of the womb, the fetus uses pheromones to communicate with its mother in a quiet code of chemical signals. This chemical link survives the baby’s birth so that a mother can identify her infant not only by his smell but also by his pheromones. Pheromones also help guide the infant’s mouth toward the nourishment of his mother’s breast. (Kodis, 1998, p.13)

The olfactory sends messages to the growing fetus so that by the time the baby is born, he or she has spent the past several months getting to know the mother’s pheromone chemistry.

What Role Does Breastfeeding Play?

Breastfeeding plays a major part in the passing of pheromones from mother to child. It does not take a child very long to learn and become partial to his or her mother’s pheromones. “At six days – some researchers say three days – awake babies can discriminate between their mother’s breasts and strange women based solely on their pheromones” (Kohl & Francoeur, 1995, p.78). While human babies have two breasts from which they are nursed equally, other nonhuman babies have several nipples to choose from and some will even favor one nipple over the rest. “Kittens nurse at one nipple only, having identified it by its unique scent” (Kohl & Francoeur 1995 p.79). Nonhuman babies rely so heavily on the scent of their mother’s nipples that if the scent were to change, the babies would die. “Instinctively a mother rat licks her nipples, unknowingly applying a salivary scent that guides her blind, hungry newborn to her breast and milk. Wash the nipples and the newborn pups lose their way and die of starvation” (Kohl & Francoeur, 1995, p.128). In this relationship, it is imperative that a baby can recognize his or her mother’s pheromones and that those pheromones remain the same.

Which Glands Are Involved?

Not only are the pheromones associated with breastfeeding important for a baby’s survival, breastfeeding also allows the baby to be exposed to his or her mother’s underarm pheromones. “Nursing at the breast exposes the infant to maternal pheromones from apocrine and sebaceous glands in the underarms and in the dark tissue around the nipples” (Kohl & Francoeur, 1995, p.79). These glands have secretions which make up a person’s body scent when mixed with bacteria living on the skin. “After birth, bacteria on the infant’s skin convert the adrenal androgens from the sebaceous and apocrine secretions into the characteristic body odor of newborns” (Kohl & Francoeur, 1995, p.142). Also, during pregnancy, these glands ensure that the infant fully develops.

At birth, male babies get a surge of GnRH which results in a LH surge. This is apparently triggered by exposure to the mother’s pheromones. The LH surge keeps the testes pumping out a high level of testosterone which further masculinizes the brain by destroying or altering connections between nerve cells and creating male circuits. (Kohl & Francoeur, 1995, p.96)

The pheromones secreted from these glands helps form humans internally as distinctively male or distinctively female. This is also pertinent in forming mate selectionideals.

How Do Pheromones Influence Infants?

A breastfed infant reaps more benefits than just being able to recognize his or her mother’s breast pheromones. “Breast-fed infants also recognize their mother’s underarm pheromones, while bottle-fed do not” (Kohl & Francoeur, 1995, p.78). Breastfeeding can influence what a child will look for in a mate when they are grown, as is demonstrated in this study of rats:

Fillion and Blass (1986) found that in male rats, odors associated with the mother during nursing heavily influenced sexual attraction in adulthood. These workers gave some nursing mother rats the odor of lemon while other retained their natural odors. Males that as pups had nursed the lemon-scented mothers preferred to mate with lemon-scented females. It appears that in many species, exposure to particular odors early in life produces lifelong preferences for these odors. (Hughes, 1999, p.293)

Just as the baby rats would die of starvation if their mother’s scent was changed by washing her with soap, so also their mate preference can be manipulated by solely allowing them to be familiar with the scent of lemon. But this does not apply to rats alone: “After mothers apply a perfume to their breasts before nursing for a day or two, infants between one and two weeks old appear to prefer the familiar scent” (Kohl & Francoeur, 1995, p.77). While changing the mother’s scent does not cause a human baby to starve, it does change the scent that the baby prefers.

There is a chemical known as oxytocin which, according to Michelle Kodis, is the “cuddle chemical. ” (Kodis, 1998, p.96) “When a mother hears her hungry baby cry, oxytocin intervenes, making her nipples erect and ready to pass the stream of milk so desired by the infant” (Kodis, 1998, p.96). This response ensures that the mother wants to nurse her baby as much as the baby wants her milk.

How Do Pheromones Benefit the Mother?

Pheromones are not only for the benefit of children; mothers also rely heavily on the unmistakable pheromones of their offspring. “Odors help nonhuman and human mothers bond to and identify their own infants. Human mothers, for example, regularly brush their noses into their baby’s hair so they can inhale its sweet odor as they cuddle it” (Kohl & Francoeur, 1995, p.128). In situations where all babies look alike, as in a litter of rats, pheromones indicate to a mother rat which babies are hers. “Mother rats identify their young by smell and can pick their own offspring out of another litter” (Kohl & Francouer, 1995, p.79).

Since babies are unable to care for themselves, pheromones signal to nonhuman mothers that they must take care of their babies. “After a ewe gives birth and nuzzles its newborn lamb, a chemical reward, a bonding hormone known as oxytocin, released in the mother’s brain tells her, ‘This particular lamb’s odor is important. Pay attention to it’” (Kohl & Francoeur, 1995, p.128). If it weren’t for this chemical bond, many nonhuman mothers may give birth and then go off and leave their young. It is also because of pheromones that mothers go into labor and feel the need to nurse. “Oxytocin stimulates the contraction of the smooth muscle of the uterus during labor and (…) facilitates milk flow during nursing” (Kodis, 1998, p.96).

How Long Can the Pheromone Bond Last?

This bond between a mother and child created by pheromones is not limited to a mother and her infant. It is a lifelong tie that cannot be broken. Below is a phenomenal story of the extent of this pheromonal bond:

A woman was visiting Oxford, England, when she found her world turned on end. She was standing by a river when a group of young male students walked by. As the boys passed, the woman had the unmistakable and instant feeling that one of these youths was the infant son she had given up for adoption only a few hours after his birth. The young man said later that he had experienced a similar visceral, gut reaction to the female “stranger” standing by the water. As he walked by, a thought flew into his brain: That’s my mother! (Kodis, 1998, pp.12-13)

The thing that makes this story even more amazing is that, according to Kodis (1998), there were no physical similarities that could have signaled to either person that the other might be related to them. It was strictly on the pheromonal bond created in the womb between this mother and her child that they recognized each other as mother and son.

The mother-infant bond produced by pheromones is one that begins in the womb and is carried out as long as both mother and child are alive. While humans do not generally readily admit the work of pheromones in their lives, not wanting to admit any animalistic characteristics, it is hard to dispute that pheromones are just as active in humans as they are in nonhumans. From an infant identifying his or her mother’s scent when only a few days old, to a youth who identifies a mother he never knew, pheromones are constantly at work within all of us.

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

Related

• Introduction to Pheromones: The Science of Smell
• Conclusion: The Science of Smell
• Menstrual Cycle Modulator: The Science of Smell
• Opposite-Sex Attraction: The Science of Smell
• Same-Sex Attraction: The Science of Smell

Evidence supporting the biological reasoning for existence of homosexuality in the human species is growing. Even though there are still some who believe that homosexuality is a choice rather than an inborn trait, stemming either from a religious or conservative viewpoint, the recent research into pheromones has a reassuring sense about the overall biological explanation of homosexuality. Researchers continue to perform experiments on mice pheromones and organs involved in the detection of homosexual preferences, including consequent behavioral responses in mice, expanding the knowledge of human pheromones. This gives conclusive evidence to support the biological reasoning for homosexuality. The total effect of pheromones is uncertain and more research is underway, but there is enough data to support a mechanical pathway of determining the sexuality of human men. In the study of human pheromones, a chemical pathway has also been identified suggesting a train of reasoning for natural occurrences of homosexuality.

How Is This Hypothesis Being Tested

Mice have been the subjects of many studies which have been done to validate the same-sex attraction reasoning. There are many benefits to using mice as study samples: the mice are mammals with a wide array of olfactory genes coding for about 1,000 ORs and around 120 to 140 vomeronasal receptors. Mice can detect up to 100,000 compounds and there are at least six pheromones identified in the mouse urine (Buck 2004, Trinh & Storm 2004, Boschat et al. , 2002). Similarly, it is fairly easy to observe the pheromone-induced behaviors, and while in other mammals it may not always be the case, in mice the chemosensory communication is crucial to the survival and reproductive success of the animal. This means that, biologically, the protein-coding sequences of the DNA and the systems and organs used in chemosensory perception are highly conserved.

How do mice studies provide this “mechanical” and chemical insight into the existence of homosexuality in human males? There are two branches of research of mouse behavior that are of interest in respect to answering this question. Both of the branches include the VNO manipulations.

What Is the First Branch of Research?

The first branch of research involves surgical removal of the VNO at some point after maturation of the male mice. These mice have been compared with wild type mice that have undergone surgical procedure in which the VNO was not removed – known as sham surgery. In addition, the behavior of these animals has been compared to castrated mice as a way of providing a second control group since the behavior of castrated males has been studied and recorded in detail.

Pankewich, Baum, & Cherry (2004) conducted a study by comparing wild type mice with an intact VNO (labeled VNOi) and mice whose VNO has been removed (labeled VNOx). Both the control group – the wild-type mice – and the test group were put through the same surgical procedure as described above. In this study mice were tested by habituation-dishabituation tests. This involved testing the preference of males to male or female urinary odorants or the amount of time spent investigating each, and by comparing the mounting behavior of sexually experienced VNOi and VNOx towards castrated males and estrous females. Dishabituation is the term describing the initial interest in a particular odorant stimulus. Habituation is the term used when mice lose interest in that odorant after getting used to it.

VNOi and VNOx male mice were able to both detect and discriminate between the volatile urinary odors from intact males and estrous females. Thus, significant increases in investigation times (dishabituation) were seen in both groups of males during initial presentation of a urinary stimulus. Also, both groups showed significant increases in investigation times during the initial switch from male to estrous female urinary odors (or vice versa) presented outside the home cage. (Pankewich et al. , 2004, p.9453)

Similarly, once the mice were allowed to investigate the urinary odorants described above inside the cage, VNOi mice spent more time investigating the estrous female urine, while VNOx mice investigated both urine samples for equal duration of time.

A seemingly problematic section of the Pankewich et al. (2004) study is the report that both VNOi and VNOx males mount estrous females and castrated males at equal rates. But, the researchers do not go into detail in discussing their findings:

When VNOi and VNOx male mice were tested over a 1 month period with an estrous female and a castrated male (with intact male urine swabbed on the back) presented simultaneously, both groups “directed an equivalent (60-70%) percentage of their mounts toward the estrous female” (Pankewich et al. , 2004, p.9454).

Although, in this study, Pankewich et al. (2004) show interesting findings in regards to
the removal of the VNO from male mice.

In Figure 2, part C, in simultaneous presentation of urine the VNOx mice spend double the amount of time investigating intact male urine than estrous female urine (left part of the graph) when stimuli are outside the cage. Consequently, VNOx mice spend exact amount of time investigating both male and female urine while the stimulus is inside the cage.

In Figure 1, parts A, B, and C, although VNOx males spend equal amount of time investigating estrous and ovariectomized females, they spend more time than VNOi males in investigating both the castrated and intact male urines.

While this research study does prove that males with an uncompromised VNO are normal, it fails to prove that surgical manipulation of the VNO does not affect the male mice. Furthermore, while the title of the study includes that “olfactory sex discrimination persists” based on the fact that VNOx males “show no preference” for estrous females – their normal, expected results – the researchers stay conservative about implying that, according to their data, VNOx males seem to prefer investigating intact male urine to estrous female urine.

What Is the Second Branch of Research?

The second branch of research manipulates the effectiveness of the VNO by eliminating the genes for the receptors of pheromones on the DNA level. This manipulation leads us to one of the major lines of evidence as to how the functionality of the VNO affects the sexual behavior in mice. The following study shows why there should be a level of caution when examining studies on such genetically engineered specimens.

The study by Del Punta, Leinders-Zufall, Rodriguez, Jukam, Wysocki, & Ogawa, et al. (2002) attempted to genetically delete the V1R genes by chromosome engineering. The researchers tested female maternal aggression known to be dependent on the VNO, and four male behaviors including ultrasound vocaliziations, male-male aggression, male-male sexual behavior, and male-female sexual behavior. The researchers concluded:

First, mutant males have a reduced sexual drive and mutant females display a reduced level of maternal aggression. Second, their VNO exhibits specific chemosensory deficits… V1R ORF [open reading frame in DNA that codes for the gene] precludes axonal convergence to glomeruli [receiving neurons in the olfactory bulb]… As pheromones in other species often consist of blends of compounds that must be present in carefully balanced ratios to elicit distinct behaviors, the deletion of V1Ra and V1Rb gene families may produce specific avnosmias [handicaps] to certain cortical components leading to an altered representation of the blend in the brain and affecting behavior. Deletion of a V1R subset may ‘corrupt’ pheromone coding instead of blocking it. (Del Punta et al. , 2002, p.73).

The problem lies in the design of this experiment where a deletion of the gene caused unexpected results: the mutant mice were identical to the wild type in all aspects not connected to the VNO function. The mutant mice were inadequate in fully decoding the pheromonal messages.

Researchers in another study using similar techniques in genetic engineering had more success in blocking the pheromonal messaging by isolating a different protein
in the VNO neurons.

Using the tools of mouse genetics and multielectrode recording, we demonstrate that the sensory information of VNO neurons requires TRP2, a putative ion channel of the transient receptor potential family that is expressed exclusively in these neurons. (Stowers, Holy, Meister, Dulac, & Koentges, 2002. , p.1493).

The TRP2 protein is found in the microvilli of the VNO neurons, a “proposed site of pheromone sensory transduction” meaning that TRP2 plays a role in pheromone communication (Stowers et al. , 2002).

The researchers proposed that TRP2 may be the primary pathway for pheromonal signaling or it might act as a factor in additive fashion of pheromonal effect. They tested the importance of TRP2 by deleting the gene and comparing test subjects with the wild type mice.

The[se] results [of multielectrode testing] suggest that… genetic ablation of the TRP2 channel eliminates the sensory responses of VNO neurons to pheromonal cues… implying that TRP2… protein could be the primary conductance of the pheromone-evoked response, or it could act as an essential component of a multisubunit channel. (Stowers et al. , 2002, p.1495)

The same study examined mating behavior of TRP2-lacking mice. That study concludes that TRP2-lacking mice display mating behavior towards females as well as males based on their inability to discriminate between males and females due to inactivity of the VNO neurons in response to pheromone signaling. Stowers at al. (2002) effectively blocked the pheromonal pathway while not tampering with the formation of the proper neural connections between the VNO and the brain, unlike the Del Punta (et al. ) researchers.

Overall, these three mice studies show that a non-functional VNO disturbs the wild type behavior of mice, and because of a lack of correct pheromonal signaling these mice exhibit indiscriminate sexual behaviors and even show preference towards male-male interaction. Any mechanical tampering – surgical or genetic engineering – leading to a non-functional VNO or lack thereof can and usually does also lead to bi-sexual if not homosexual behavior in mice.

What Can Mice Teach Us about Human Sexuality?

As we have seen, a homosexual behavior can be induced manipulating the detection mechanism of pheromones in mice. Unfortunately, it is impossible to study pheromones in humans in the same fashion because of obvious ethical problems. Instead, researchers of the Kariolinska Institute in Sweden have isolated two chemicals proposed to be human pheromones and have conducted a study by comparing the effects of these chemicals on heterosexual men and women, and homosexual men. The data were obtained by two methods: positron emission tomography (PET) scans and magnetic resonance imaging (MRI) scans of the brain. PET is a common procedure used in medicine to detect certain diseases by scanning for tiny radioactive molecules administered to the patient intravenously. MRI is a similar procedure that scans the body with powerful magnets distinguishing among different tissues based on their density and magnetic resonance. The effects of two chemicals, previously mentioned 4, 16-androstadien-3-one (AND) a derivative of testosterone, and estra-1,3,5(10)16-tetraen-3-ol (EST) an estrogen-like steroid were compared to common odors and air. (Savic et al. , 2005)

The design of the experiment left nothing to chance. Twelve maximally gay men were compared to twelve straight women and twelve maximally straight men. Special testing was done to establish the sexuality of each test subject. Bloodwork was done each day at the same time of the day to test for levels of different hormones. The scanning was done at the same time of the day during which equal amount of time was spent smelling each of the odors. An excellent understanding of the human brain was described by researchers using several references. This description is necessary to understand the complete significance of the research. (Savic et al. , 2005) However, the two main areas of concern are the hypothalamus and olfactory cortex – regions discussed previously.

The hypothesis-based [region of interest] analysis showed that [homosexual men] processed AND congruently with [heterosexual women] rather than with [heterosexual men]… …The explorative statistical parametric mapping analysis confirmed that [heterosexual women] showed activation of the anterior hypothalamus with AND, whereas, in [heterosexual men], this area was recruited during smelling of EST. (Savic et al. , 2005, p.7359)

In retrospect, homosexual men and heterosexual women had similar responses to AND in the same way that heterosexual men responded to EST. Savic et al. point out in a previous study of effects of these chemicals on heterosexual students that they obtained similar results when students were smelling opposite sex stimuli whereas when these students smelled the same sex stimuli only the olfactory cortex of the brain was activated. (Savic-Berglund, 2004)

To explain these findings involves proposing the activation of two different pathways [of processing]: the ordinary olfactory response, which involves the olfactory tract and its usual connections, and another pathway activated by pheromones depending on the sex of the responder. (Savic-Berglund, 2004, p. 206)

The more recent study of these chemicals confirmed the researchers’ speculation about the effects of these chemicals, but not according to the sex of the test subject:

As discussed, signals form AND and EST seem to be bimodal, and primarily mediated either by the hypothalamus or by the olfactory regions. Consistent with the fact that both compounds were odorous, the conjunctional analysis showed involvement of olfactory areas even when hypothalamic pathway predominated. The major finding in the present study was that the preferred pathway in relation to the presented compound was associated with the responder’s sexual orientation (at least in men) rather than biological sex. (Savic et al, 2005, p.7359)

Dulac and Torello (2003) effectively discuss the overall significance of the combined pheromonal research in mice and humans in their discussion Box 1. They discuss the existence of key receptors (therefore genes) and organs that are involved in the detection of odors and pheromones.

Two large families of G-protein-coupled receptors that are expressed in the VNO and hypothesized to be pheromone receptors have been found in mouse and rat. However, most of the human orthologues of those genes seem to be non-functional pseudogenes… mining of the human genome['s] 200 sequences with homology to the V1R family… one has been found in the olfactory mucosa (Dulac & Torello, 2003, p.552)

Nonetheless, we have learned that the detection of olfactory stimuli is not solely ascribed to the main olfactory epithelium, and pheromones are effectively transported among individuals. However, because the human VNO doesn’t play as great a role in pheromone communication as it does in mice, the chance for a “corrupted” signaling pathway as a response to pheromones greatly increases to possibility of persistence of human homosexuality.

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

Related

• Opposite-Sex Attraction: The Science of Smell
• Menstrual Cycle Modulator: The Science of Smell
• Introduction to Pheromones: The Science of Smell
• Conclusion: The Science of Smell
• Mother-Infant Bonding: The Science of Smell
• De-Sexing the Bonobo
• How much do college students really study?

When thinking about mate selection, rarely do thoughts turn to science and biology, although both are shown to play an important part of mate selection. There are no romantic comedies called Love at First Sniff or articles in Cosmopolitan entitled: How to Get the Best Body Odor. But as research shows, noses provide many biological mating cues. Some of these are found in the form of pheromones.

Humans’ sense of smell has by far been underestimated in the past. Like other animals, “humans use olfactory signals for the transmission of biologically relevant information” (Grammer, Fink, & Neave, 2004, p.141). Researchers investigating body odors have speculated that pheromones are key in mediating socio-sexual effects. “Pheromones, which are ubiquitous among animals, have only recently been seriously considered as signals in human mate choice” (Cornwell et al. , 2004, p.635). Researchers are still at odds about where pheromones are interpreted within humans, though Wysocki & Pereti (2004) believe that the olfactory system detects and interprets pheromones.

How and Where Does the VNO Function?

The VNO has been shown to detect pheromones in other species. Some researchers believe the VNO does not exist in humans, while others believe it does exist in humans but does not function as it is understood to function in other species. Grammer et al. (2004), on the other hand, theorizes that humans do possess a functional VNO which responds to pheromones in sexual-specific manners. The only commonly agreed upon fact regarding the VNO is that it is visible and functioning in the fetus. Yet researchers disagree about whether it shrinks or entirely disappears after the fetus is born.

While the VNO is a controversial subject, the majority of research shows that it is important to the processing of pheromones. The VNO is located above the hard palate on both sides of the nasal septum and it is lined with receptor cells whose axons project the accessory olfactory bulb, which sends its projects to the hypothalamic nuclei (Grammer et al. , 2004).

It is also believed that “the VNO system, through its close connections with the reproductive hypothalamus, is the primary pathway for bringing about neuroendocrine changes – the kind involved in puberty acceleration, estrous inductions, and pregnancy block” (Keverne, 2004, p.177). Keverne (2004) also states that the VNO links directly with limbic brain structures, which are important for the development and expression of primary motivated behavior (sexual, aggressive and maternal behavior). These behaviors are linked with reproduction. Other research suggests that the olfactory is where pheromones are detected and processed. The strength of this argument comes from the biological functioning of the ORs, which Grammer et al. (2004) suggests send projections to the neocortex for conscious processing (e.g. the nature of a particular aroma) but also to the limbic system for emotional processing” (e.g. memories and affect associated with a particular smell. )

How Do Humans Assess Mate Quality?

In humans, it has been known for some years that “the olfactory receptor genes are expressed in the testis and appear to be functionally linked to the Major Histocompatibility Complex (MHC) on various chromosomes” (Keverne, 2004, p.185). The MHC helps the body to recognize its own healthy cells. Humans have the largest MHC/olfactory receptor-linked cluster of any organism so far investigated.

Some researchers believe that our vision may have taken over for the VNO. According to Grammer et al. (2004). , the visual stimulus is important in socio-sexual contexts, but when personal intimacy is increased, it is likely that smell also plays a key role in a variety of socio-sexual behaviors. Together our vision and our olfactory receptors help us today to make mate selections. Grammer et al. (2004) suggest that humans use multiple signals as a way of reducing error when assessing mate quality. Pheromones are a biological measure to help reduce error.

Up to this point, human pheromones have been known chemically as volatile steroid molecules (Beier et al. ,2004). The most studied steroid within humans is called 4, 16-androstadien-3-one (AND) is found in secretory epithelium. Apocrine glands develop in the embryo, but become functional only with the onset of puberty. At sexual maturation, these glands produce steroidal secretions derived from 16-androstenes via testosterone. AND is significantly higher in males than females. (Grammer et al. , 2004) “The apocrine glands and AND work together to correlate structure and function with approaching sexual maturity and do not begin their secretory activity until puberty” (Beier et al. , 2004, p.61). Beier et al. (2004) hypothesizes that there is a direct link between androgen action and induction of pheromone production in the aprocrine glands of the human axilla.

High concentration of apocrine glands found in the armpits led to the term axillary organ (Grammer et al. , 2004). This is considered an independent organof the human odor production. Axillary secretions and odorants are centralized in areas where hair and sweat can be found together. The centralized point in men is positioned at the nose level of average-height women – men’s arm pits. When apocrine is first secreted, it is odorless, but it is then transformed by bacteria.

How Does Ovulation Affect a Woman’s Sense of Smell?

At the time of ovulation females’ smell sensitivity peaks and female subjects found androstenone to be more pleasant and appealing than at other times during their cycle. These results suggest that there is a recordable change in the emotional evaluation of males, and this could be triggered by androstenone. Female subjects generally report male body odor as unpleasant and unattractive, but during ovulation, when conception is imminent, these feelings change, and this change could have a strong impact on mate selection.

Studies have also been conducted on female odors to determine if men’s mate selection is affected in any way by pheromones and scent. In the vagina, aliphatic acids are secreted and their odors vary within the menstrual cycle. Doty used a questionnaire to evaluate the intensity and pleasantness of different vaginal fluids from a complete menstrual cycle (Grammer et al. , 2004). They found that odor at ovulation was both the most intense odor and least unpleasant. In one study, ovulatory fatty acid compositions stimulated male androgen secretion and changed the discriminatory cognitive capacities of males with regard to female attractiveness; males became less discriminating (Grammer et al. , 2004).

In a study by Cutler et al. , male volunteers recorded the occurrence of six socio-sexual behavior – petting/ affection/ kissing; formal dates; informal dates; sleeping next to a partner; sexual intercourse; and masturbation – over a total of eight weeks, which included a two-week baseline (Grammer et al. , 2004). The men added a synthetic male hormone to their usual cologne or aftershave. In general 58% of the pheromone group, compared to 19% of placebo group showed increases in two or more behaviors compared to baseline. Forty-one percent of the pheromone group compared to 9.5% of the placebo group showed increases in three or more behaviors compared to baseline. In a separate study by McCoy and Pitino, 36 female subjects recorded the occurrence of the following socio-sexual behaviors – sexual intercourse, sleeping next to a partner, formal dates, petting/affection/kissing, and male approaches – over a two-week baseline followed by a six-week span where they applied a synthetic female pheromone. In terms of percentages, three or more socio-sexual behaviors increased over their baseline in 74% of pheromone users, and only 23% in the placebo group (Grammer et al. , 2004). The high percentages found in both research groups, give a positive account that pheromones do, in fact, impact humans. Even with this research, there is some dissension among the researchers regarding whether pheromones actually influence our mate selection.

How Does Mate Selection Work?

Mate selection is a task of information processing. Evolution favors individuals who are able to quickly and reliably process information that allows them to make the appropriate mating decisions (Grammer et al. , 2004 p. 140). It is often hypothesized that since neither males nor females can adequately determine when a female is ovulating, women are able to “trick” men into staying in a relationship. Because males are unaware of females’ fertility, men are more or less forced to remain with the same mate until they are confident impregnation has occurred. If a female were to provide cues as to when she was ovulating, it could make finding a helping partner more difficult (Grammer et al. , 2004).

Some researchers and scientists believe that hidden ovulation gives women the upper hand in the mating world. Other researchers believe that women are seeking good genes during the mating process. Pheromones attribute to this theory. According to some studies, women seem to prefer the odors of immunocompatible men, meaning that each part of the couple donates immunity that the other partner does not donate. This gives the offspring more of an opportunity to survive after birth.

While the mating system of ancestral hominids is unknown, it is likely that during hominid evolution there was at least some male investment in mating and offspring upon which natural selection has shaped modern human mating behavior (Cornwell et al. , 2004).

Can Humans Interfere with Pheromones?

In regards to pheromone production and reception, there are two modern factors that researchers are concerned with: oral contraceptives and our Western obsession with cleanliness. In two studies conducted by Claus Wedekind and Sandra Furi (1997), female pill users tended to choose pheromone scents that were more aligned with their own MHC. Since the partners share the same immunities, the risk of inbreeding increases. Wedekind & Furi (1997) hypothesize that the reason pill users’ pheromone detection is impacted is because the pill is mimicking pregnancy. He also believes that pregnant women have different aims when it comes to mate selection; they are aiming for a “helper” during and after childbirth.

Another concern of researchers is our obsession with bodily cleanliness. Wedekind & Furi (1997), through their research, are convinced that even though we are obsessed with cleansers, perfumes, and deodorants, nature still functions. Our nose and olfactory glands are stronger and more robust than originally thought to be – still giving nature the ability to help chose our life partners so that our offspring has the best chance for survival.

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

Related

• Same-Sex Attraction: The Science of Smell
• Conclusion: The Science of Smell
• Introduction to Pheromones: The Science of Smell
• Menstrual Cycle Modulator: The Science of Smell
• Mother-Infant Bonding: The Science of Smell
• De-Sexing the Bonobo
• Love Styles: An Analysis

Bonobos represent one of the primate species that most often fall victim to these mistakes. The rare apes intrigue the public and researchers alike with their “erotic” lifestyles, filled with seemingly inhibited sexuality. Attracted to their “lascivious” existence, humans project their own fantasies and notions about sexuality onto the ape species. This intense focus on the sexuality of the bonobo may overstate the importance of sexual relations in their behavior. In reducing the bonobos to “horny apes” the general public, as well as researchers, deemphasize other extremely important aspects of bonobo behavior.

Of course undeniable similarities exist between bonobos and humans which must not be ignored. Because of their close phylogentic relationship to humans, these similarities should be addressed. Like humans, bonobos are sexually receptive for extended periods, they exhibit a powerful sexual life that is strongly connected to food, and they appear to walk easily on two legs (de Waal, 1996). While many other parallels exist, the high degree of sexuality among both species receives the most attention. This tendency can be very positive in bonobo research as “it is impossible to understand the social life of this ape without attention to its sex life; the two are inseparable” (de Waal, 1997). The focus, however, can carry negative consequences. Animals should not be studied merely because the general public and researchers find them titillating. After reading several bonobo studies and any pop literature on the species, a researcher would find it difficult to avoid the impression that “a more puritanical ape would be less worthy of [their] attentions” (Zuk, 2002)

In focusing on sexual similarities between humans and bonobos, researchers can forget or downplay the many dissimilarities between the two species -one of the most important of which is ecological differences. Diet almost surely affects gender relations and social structures. Perhaps bonobos are “gentler apes” because they exhibit a more heavily herbaceous diet than either chimps or humans. This diet allows the bonobos to forage in groups and circumvents tensions that result from feeding on clumped resources such as fruits (Strier, 2003). Aside from subsistence strategies, other differences between humans and the apes exist- there are, for instance, no observations of male cooperations among the apes, females are as mobile as males, and pair bonding is unknown in bonobos (de Waal, 1996).

Due to human fascination with sex, researchers must remember to address interspecies differences and to consider that “while sex is central to bonobo life, that life and not the sex itself is the central focus to most scientific work” (Zuk, 2002). Because of their own culturally imbued reactions to bonobo behaviors, researchers might view bonobos as oversexed, salacious beings. Bonobos, however, lead their “erotic” lives without acknowledgement of taboo or prohibited actions. Because they articulate sexuality as a natural aspect of their behavior, “it would be a distortion to view their behavior as an expression of “sexual freedom” (de Waal 1996). Bonobos do not concern themselves with sexual morality- an issues that, even for humans represents a highly variant trait (de Waal, 1996).

Perhaps researchers fall victim to moralizing bonobo behavior because of how human-looking their sexual relations appear. Bonobo vaginas and clitorises are ventrally located, leading to greater ease of face to face copulations. Phone sex therapist Susan Block latched onto this trait and declared that “like tanctric sex practitioners or two people very much in love, bonobos often look deeply into each others eyes” (Zuk, 2002). Block has created a pseudo-psychological theory for better relationships based upon bonobo sexual relations. Her method, “Pleasure Eases Pain, Good Sex Defuses Tension, Love Lessens Violence” capitalizes on theories that bonobos use sex to reduce aggression and tension. While this may be true, it hardly seems appropriate to use a species without significant pair bonding as a role model for building strong relationships. Pseudo-theories such as this encourage the general public’s one-sided view of bonobos as “sexy apes.” Even respected researchers occasionally anthropomorphize bonobos into zealous lovers. In describing how bonobos use sex to diffuse tensions, Franz De Waal makes a passing comment about bonobos as the “original proponents of make love not war” (1996). “Love,” a culturally defined- as well as culturally variant concept, holds a tenuous place in the scientific study of primates.

While, probably more than any other researcher, Franz de Waal recognizes the pitfalls of over-focusing upon bonobo sexuality, he is not immune to it. Nor does he avoid taking advantage of the bonobo for feminist purposes. In a 1995 Scientific American article, he refers to the bonobos as a “gift to the feminist movment.” The movement had indeed combated early chauvinistic primatology models. Early primatology undoubtedly focused on male behavior, to the detriment of the field. Male researchers stressed male relations and dominances struggles while relegating females to the field of infant rearing (Strier, 2001; Zuk, 2002). This early approach led to several false conclusions such as incorrectly assuming that baboon society was male dominated (Strum, 2001). After the rise of the feminist movement, however, the field of primatology changed. Women now dominate the field and all primatologists are keenly aware of both genders of their subjects.

Some may argue, however, against using apes and monkeys as mascots for the feminist movement. The female alliances of bonobos present an attractive and easily co-optable argument for the movement. Unlike baboons, female bonobos cooperate without being genetically related (Zuk, 2002). They are a female transfer species with close female bonds. These close bonds have been demonstrated to create coalitions which “keep the males in place” (Wrangham, 1996). Such a take on female behavior presents an attractive model for the feminist movement to capitalize upon- one in which women band together to rise up against male oppression. While feminists should undoubtedly continue to struggle for women’s equality, adopting an animal as movement symbol presents significant scientific challenges. Overemphasizing the females of a species engenders that species as a whole.

With this view, animals such as chimpanzees become “male” species while bonobos are “females” (de Waal, 1997). The bonobo/chimp divide thus begins to represent human gender issues. This simplification of behavior ignores important data and imbues species with unempirical quality statements that lead to favoring one species over another. Bonobos and chimpanzees have been demonstrated as phylogentically equidistant from humans, yet many researchers debate about which species best represents human origins. This debate should be replaced with views that acknowledge the parallels among humans and both species. It should also focus upon the behaviors of both genders of a species.

Both bonobos and humans demonstrate an active interest in sex as well as a colorful sexlife. When studying primate behavior, however, the human fascination with bonobo sexuality should be carefully monitored. Bonobo sexuality represents a vital area of the ape’s life but researchers should be careful not to overstress the sexuality of the species. This extreme emphasis upon sexuality can lead to ignoring differences between the bonobo and human species and disregarding important ecological and behavioral data. Too much focus upon the erotic lives of the bonobos anthropomorphizes them into lusty animals, denying them existence as beings acting in a manner most natural to them. This focus can be abused by those without scientific intentions. Sex therapists and some in the feminist movement have already manipulated the bonobo for their own causes. Their actions transform the bonobo from a complex species into a caricature. For many years, researchers have been aware of the detrimental effects of anthropomorphizing their subjects. With further study of the bonobo, primatologists should be ever vigilant to the extreme sexualization with which the ape has been painted. Sexuality represents a central part of the bonobo’s life but researchers must not let it define the species.

Citations

De Waal F, 1995. Bonobo Sex and Society: The Behavior of a Close Relative Challenges Assumptions about Male Supremacy in Human Evolution. Scientific American March: 82-88.

De Waal F, 1997. Bonobo: The Forgotten Ape. Los Angeles: Berkeley and Los Angeles University of California Press.

De Waal F, 1996. Bonobos. In: Peacemaking among Primates. Cambrigde, MA: Harvard University Press; 171-227.

Strier K, 2003. Female Strategies. In: Primate Behavioral Ecology (Hanson K, ed). New York: Allyn and Bacon; 200-231.

Strum C, 2001. Starting Out. In: Almost Human: A Journey into the World of Baboons. Chicago: University of Chicago Press; 6-22

Wrangham R, Peterson D, 1996. The Gentle Ape. In: Demonic Males: Apes and the Origins of Human Violence (. New York: Mariner Books; 200-219.

Zuk M, 2002. Bonobos: Dolphins of the New Millennium. Sexual Selections: What We Can and Can’t Learn About Sex From Animals. Los Angeles: Berkeley and Los Angeles University of California Press; 107-120.

Related

• Opposite-Sex Attraction: The Science of Smell
• Introduction to Pheromones: The Science of Smell
• Conclusion: The Science of Smell
• A Sinking Earth
• Same-Sex Attraction: The Science of Smell

Memory is a tool on which many people rely heavily every day. How and what is remembered plays a significant role in determining how people act in their daily lives (Araya, Ekehammar & Akrami, 2003). It is important to understand how memory works as a way of understanding more about people in general, and specifically about how the brain stores information. With this information people can be helped to expand and build memory, those with learning disabilities can be treated, and eyewitness testimony can be filtered for accuracy (Dysart, Lindsay, Hammond & Dupuis, 2001). Understanding memory has and will continue to influence many disciplines and help uncover the myriad mysteries of the mind (McNamara & Wong, 2003).

Researchers have spent decades studying the mechanisms of memory (Ho, Cheung, & Chan 2003). There are several different types of memory, such as episodic, which allows people to remember specific events with striking clarity. Implicit memories are pieces of information people know, but are not aware of the source. Conversely, explicit memories are pieces of information people can remember and they can also remember when and how they acquired that information.

Most researchers believe that a piece of knowledge must pass through a series of “gates” before it is permanently stored in memory (Ward & Loftus, 1985). The first of these gates is called working memory, where objects that are being attended to at the present moment are stored. Objects in working memory can remain there anywhere from two seconds to several minutes before either being forgotten or passing though the next gate, known as short term memory.

Short term memory is similar to working memory, and not all researchers agree on the distinction between working memory and short term memory (Hinson, Jameson & Whitney, 2003) However, short term memory is considered to be the staging area where the fate of a piece of information is decided; it will either fail to be encoded as a memory, and so be forgotten, or it will pass into permastore, where long term memories are held. Approximately 7 items can be stored in short term memory at one time.

With this knowledge, researchers have been able to test memory skills under a variety of conditions and in many circumstances, to arrive at a better understanding of memory skills and function. In order to attain this knowledge, most of the research in memory has been aimed at short term or working memory (Hinson, Jameson & Whitney, 2003). For example, researchers know that information to which people are exposed in passing can sometimes remain, subconsciously, in memory and can influence future decisions (Bushman & Bonacci, 2002). This information is frequently used in advertising, where advertisers hope that frequent exposure to their products will prompt more purchases at the store. Extensive market research has shown that consumers are indeed influenced by this exposure (Bushman & Bonacci, 2002).

In the 2003 study by Hinson, Jameson and Whitney, it was found that individual differences in working memory are related to decision making that favors short-term over long-term consequences. People with more efficient working memories were better able to process and weigh the differences between a short-term reward, which appeared better at first glance, and a long-term reward, which was actually the better choice. There were some differences noted in the working memory processes of the individuals who chose the long-term reward.

One of the most popular areas of memory research is that of eyewitness testimony and identification (Dysart, Lindsay, Hammond & Dupuis, 2001). In a study by Dysart and colleagues (2001), there was significant evidence to show that eyewitnesses who had been shown mug shots of suspects prior to participating in a lineup were more likely to choose a suspect to whom they had been previously exposed. The implications of this research are monumental: A suspect can be incarcerated on the basis of testimony that may have inadvertently been planted in memory by the viewing of mug shots. With this research, the lives of many innocent people may be spared.

Another study on eyewitness performance by Ward and Loftus (1985) showed that when two people witness the same event, their memories will be different. They also found that people with certain personality traits were more likely to me misled by false information.

Verbal and visual memory are two more types of memory. Verbal refers to remembering associated with words, like how many words a person can remember when they hear them read aloud. Visual memory refers to the amount and accuracy of recollections having to do with visual stimuli, such as the details of the slide show in the current study. It has been found that verbal memory is affected by interference in working memory (Woodman, Vogel & Luck, 2001). For example, if a person is asked to remember a series of words that are read aloud, and then must complete a task that fills their working memory, they are much less likely to accurately recall the words. Since verbal and visual memory are closely related, logic would assume that the same rule would hold true for visual memory.

To this end, it is hypothesized that the more interference that is present between the stimulus and the desired response, the less accurate the participants’ responses will be. Group 1, which has only a time delay, should have the most accurate responses, and there should be a significant difference between the accuracy of the responses of group 2, which had the easy task interference condition, and group 3, which had the difficult task interference condition.

Method

Participants

Participants were 17 undergraduate students enrolled in the Thursday lab section of experimental psychology at Rutgers University. Group 1, the control group, consisted of 5 students, while groups 2 and 3 consisted of 6 students. Students were randomly assigned to groups as they entered the classroom. Students who participated were given class credit for their participation in this and several other experiments.

Procedure

It should be noted that this study was conducted after a very short study in this same lab period. Participants may have had less interest in this study because they were told it was the longer of the two, or they may have been impatient to leave. Participants were shown a brief slide show of a man visiting several stores, examining merchandise, and shoplifting several items. Group 1, the control group, was then required to sit quietly for 5 minutes, while group 2 completed an easy task and group 3 completed a difficult task. The easy task was to look for pictures of items in a newspaper and to record the page number on which they were found on a questionnaire. The difficult task was to complete the crossword puzzle in the newspaper and writing a brief assessment of one’s puzzle solving abilities.

After the 5 minute period, all participants read a narrative that told the same basic story as the slide show, but with some misleading and some reinforcing statements.

After the narrative, another 5 minute period followed in which group 1 was required to sit quietly, group 2 completed an easy task, and group 3 completed a difficult task. The easy task was again identifying pictures in a newspaper, while the difficult task consisted of answering questions based on information embedded in different newspaper articles.

After the second 5 minute period, all participants were tested on their memory of specific details from the slide show.

Results

The data indicated support for the hypothesis that the group with the most interference between the slide show and the questions would yield the most inaccurate responses. However, group 2 (easy task), out-performed both group 1 (control group), and group 3 (hard task). It appears that when slightly challenged, participants perform at their optimal level.

Group 1 performed better than Group 3, but not as well as Group 2. This may be attributable to the fact that the participants of Group 1 had nothing with which to occupy their minds except their own thoughts, and they may have grown bored and disinterested during the two periods of down time. Group 3 did have the fewest accurate responses, due to the fact that their tasks were the most challenging and required the most abstract thought. These results are in keeping with the hypothesis that, with too much interference, the brain is unable to store a lot of information in working memory. However, the hypothesis did not anticipate that no interference at all may in fact prove more distracting than a small amount of interference.

Though our experiment yielded results which seem to be an accurate demonstration of the capacities of memory, further research is highly suggested. Due to the fact that this lab class has only minimal students and several were absent during the experiment, the results may not be as reliable as possible. Having a large sample group is an important factor for any experiment. Because these experimental groups were so small, it would be advisable to try and re-create these results with a larger, more diverse subject pool.

In the questionnaire regarding the slide show, the questions were classified as reinforced: items in the slide show were mentioned correctly in the narrative (e.g. yellow candle); misled: items in the slide show were mentioned incorrectly in the narrative (e.g. white candle); slide only: items in the slide show were not mentioned in the narrative; and neutral: items in the slide show were mentioned in the slide show, but with no modifiers (e.g. candle). There were four (4) misleading questions, eight (8) slide only questions, four (4) neutral questions, and four (4) reinforced questions.

All groups performed the same or better with reinforced questions than with any other questions. Group 1, the control group, had a 90% overall accuracy for reinforced questions, 87.5% for slide only, 85% for neutral questions, and only 40% for misleading questions. Group 2, the easy task group, had 87.5% overall accuracy for both the reinforced and slide only questions, 79.2% for neutral questions, and 66.7% for misleading questions. Group 3, the hard task group, had 95.8% overall accuracy for reinforced questions, 85. 4% for slide only questions, 70.8% for neutral questions, and only 33.3% for misleading questions. Out of all the groups, group 3 had the best overall accuracy for reinforced questions, and the worst overall accuracy for misleading questions.

Group 2 had the least variance, a 20.8% difference, in their overall accuracy between the misleading and reinforced questions, group 1 had a 40% variance, and group 3 had 62.5%, the most variance.

All 3 groups rated themselves similarly to one another on confidence judgments, and across all categories of questions. Across all 20 questions, Group 2 rated themselves an overall confidence of 87.81%, Group 1 rated themselves an overall confidence of 88.48%, and Group 3 rated themselves an overall confidence of 88.57%. All groups rated their performance within 1% of each other. However, Group 3 (hard task), who yielded the least accurate responses, rated themselves highest in confidence. Group 2, (easy task), who yielded the most accurate responses, rated themselves lowest in confidence, and Group 1 (control group) rated themselves right in the middle.

Group 3 showed an overall accuracy for confidence judgments of 71.35%, Group 1 showed 75.63%, and Group 2 showed 80.21%. Group 2 did nearly 10% better than group 3 and nearly 5% better than group 1.

Conclusion

A most interesting phenomenon lies in the results of the confidence judgments. It appears that participants have no true idea of their actual accuracy in answering questions. Regardless of their actual accuracy, all 3 groups rated themselves fairly high on their confidence levels, and extremely close to one another. These results are in keeping with the findings of Elizabeth Loftus (1986), who demonstrated that individuals’ confidence of their answers has no bearing on their actual results.

It appears that, for working memory to function at an optimal level, some interference or distraction is desirable. When individuals are forced to concentrate too avidly on a task, they appear to lose interest and become easily distracted from their goal. When there is too much interference or distraction, however, the individual is unable to recall all the information from working or short term memory, probably due to the fact that they are forced to channel their concentration almost completely into other areas. Therefore, the data lead to the conclusion that a low level of distraction has the capability of driving the memory to achieve greater results.

It would be interesting to try to replicate these results with a larger group of participants, and also to create more distinction between the difficulties of each group’s task. Doing so may yield more detailed information on the intricacies of working memory.

Related

According to the Flight Safety Foundation, a leading organization dedicated to lowering the risks in aviation, the four most pressing aviation safety issues are Controlled Flight into Terrain (CFIT), Approach and Landing, Loss of Control and Human Factors. Of these four, the top priority for the Flight Safety Foundation is reducing accidents as a result of Controlled Flight into Terrain.

The FAA defines CFIT as occurring “when an airworthy aircraft is flown, under the control of a qualified pilot, into terrain (water or obstacles) with inadequate awareness on the part of the pilot of the impending collision.”[2] CFIT accidents are responsible for more than half of all commercial aviation fatalities during the past 10 years.[3] In General Aviation, CFIT accidents account for seventeen percent of all accidents.[4]

A CFIT accident is the accident category most clearly attributable to human error. In considering the definition, there is a qualified pilot flying a perfectly flyable airplane yet the flight ends in an accident. The definition includes assigning the blame as inadequate awareness on the part of the pilot, in other words, human error.  These types of accidents occur either because the pilot is laterally displaced from the intended position or the pilot is lower than intended, sometimes both.

Most aviation accidents can be traced back to a human error but CFIT accidents are particularly troubling due to the percentage of fatalities as a result of the accident.    The goal of prevention lies in giving the qualified pilot more resources to increase awareness and to prevent the CFIT accident. There are two ways to begin to decrease the risk of CFIT accidents. Either the qualified pilot receives more training or the qualified pilot is given better technological resources in the cockpit. Ideally, the qualified pilot will have both.

To eliminate as much human error as possible, technologies have been developed to assist the pilot. There are a variety of systems available for all areas of aviation but the technology of the Enhanced Ground Proximity Warning System is considered to be the most useful advance to date. Flying Magazine has called it “one of the most important safety advances in decades.”[5] EGPWS is prohibitively expensive for use in General Aviation so this paper will focus on the description and use of the EGPWS technology in the commercial airline industry.

What was needed in the cockpit was a system that would monitor the flight path and provide a warning to the pilots if impact with terrain was imminent before any unusual flight maneuvers would have to be employed. Prior warning systems were interfaced with the radio altimeter, which had limitations. The older systems would keep track of the airplane’s height via the radio altimeter settings and then give an aural alarm if a downward trend was detected. It would only give indications based on correct altimeter settings and did not have the ability to “look ahead” of the airplane to detect possible terrain collisions. The EGPWS was a major improvement for the simple fact that it would utilize a terrain map database via Global Positioning Systems to provide the pilots with a more reliable source of data. It would give a visual and an aural warning for terrain warnings.   The warnings sound approximately 60 seconds before terrain impact giving ample time for the pilot to make corrections. The older Terrain Warning Systems would give only 15-30 seconds warning before terrain impact.

The early EGPWS interfaced only with the Flight Management System on the aircraft. This interface worked well within the contiguous United States and Europe but in the more remote areas of the world such as Africa the EGPWS data had to rely on possibly outdated terrain data in the FMS. The original intent of Honeywell’s EGPWS was to have the system download independent GPS input and provide accurate terrain display no matter how old the FMS data might be.

The Austrian writer, Karl Kraus said, “The development of technology will leave only one problem: the infirmity of human nature.”[6] With all new technological advances, it would be a useless application if it were not an intuitive tool for the pilots for whom it may save. Before working on the technical aspect of the hardware, the engineers recognized that abiding by the FAA recommendation to consider the human factors in presenting a new function in the already familiar cockpit would be a solid course of action.

The FAA understands that before the engineers devise new technologies they should first consider the human factors framework in which this new technology will be used. To that end, the FAA published a report in 1996 which in part states, “Recommendation Processes-1: The FAA should task an aviation industry working group to produce a set of guiding principles for designers to use as a recommended practice in designing and integrating human-centered flight deck automation.”  And “Recommendation SA-3: The FAA should encourage the aviation industry to develop and implement new concepts to provide better terrain awareness.”[7]

The older terrain warning systems had a set of functions that are now considered standard. They include warnings for Rising Terrain, Excessive Descent Rate, Descent After Takeoff, Terrain Clearance, Descent Below Glideslope, Alltitude Callouts, Smart

500 foot Callout, Excessive Bank Angle Warning and Tail Strike Warning.

The enhanced features of the Enhanced Ground Proximity Warning System that earned the system it’s accolades are as follows:   Enroute Terrain Display – PEAKS, A Detailed Terrain Database, Obstacle Database, All publicly Known Airports, Look Ahead Algorithms, Terrain Alerting,  Pop-up feature, Geometric Altitude and Envelop Modulation.

Enroute Terrain Display-Peaks

Flying is a visual activity so care in considering how to display the information is of high priority. One display issue is what colors should be used for terrain awareness. One universal standard color scheme would be followed in the use of Red, Yellow and Green. Red is an urgent warning for the crew to take action, Yellow signifies that the crew should be aware of the terrain, Green symbolizes that the crew is in the clear and no action would be necessary. The color palate is used in the same manner as it is used in the outside world. For example, consider a traffic stoplight, Red is the color used to denote a definitive Stop signal, Yellow provides a caution warning and Green is an all clear. Utilizing aspects from other areas of life to match how to respond to various display indications in the cockpit will decrease the possibilities of negative transfer. Negative transfer is defined as “the interference of previous learning in the process of learning something new, such as switching from an old manual typewriter to a computer keyboard.”[8]

“The EGPWS terrain display utilizes five colors; red for terrain well above the aircraft, yellow for terrain slightly above and below the aircraft, green for terrain well below the aircraft, cyan for significant bodies of water and black for no threatening terrain.”[9]

During daylight hours the colors are more brightly displayed in order to be more visible to the flight crew. As slight a difference this may sound, the brightness factor could be critical. In an aircraft I recently started flying, I had thought that my Distance Measuring Equipment (DME) was INOP and I had chosen a different instrument approach than I had intended or even preferred. Later that evening, during dusk, I noticed that the DME was operating once again. It occurred to me that the DME was working all day but did not have a bright enough display to be seen during daylight hours. Fortunately, I did not have to rely on that cockpit instrument in order to safely complete the flight.

The PEAKS function will give highest and lowest terrain in feet of sea level numerically displayed on the side of the main map display. This allows for yet another level of increased awareness of the surrounding terrain.   The flight crew not only has the pictorial view of the terrain but it is reinforced by a graphical/numeric indication for a quick reference. The numeric display is color coded to correspond to the color coding on the terrain display. The number corresponding to the highest peak and lowest peak in the area will be displayed in whatever color it is represented on the display.

Detailed Terrain Database/Obstacle Database/All Publicly Known Airports

With Interfacing the Terrain display with a Global Positioning System the EGPWS is able to provide the flight crew with a more accurate terrain display than previous models used.

Look Ahead Algorithms

The display would not only need to show appropriate colors but also give correct terrain information in a timely manner. A major improvement that was needed to assist the flight crew was a longer lead time in order to respond to aural and visual warnings of impending terrain impact. Earlier systems would give a 15-20 second warning but often this was not enough time. Flight crews, when faced with a system that in the past has “cried wolf” and alerted the crew of impending terrain impact but was actually a false warning created an “accident waiting to happen” scenario. When a crew is given 15-20 seconds to respond to a terrain avoidance warning but takes time to discern whether or not it’s a true or false warning the hesitation to pull-up may put the flight in danger. One case to consider is the USAF 737-200 that crashed into a hillside while flying an NDB approach into Dubrovnik, Croatia carrying U.S. Secretary of Commerce, Ron Brown. The flight was off course, to the left of the inbound course of the approach, and installed on the airplane was an early model terrain avoidance system. The investigators could not confirm if the system was operational. If operational, the flight crew would have received a terrain warning 20 seconds before the impact. In this case, that was not enough time to execute the pull-up and avoid the accident.[10] The engineers on the EGPWS project were charged with the responsibility to increase the visual and aural warning to occur with enough lead time for the flight crew to respond. The EGPWS will provide warning indications 60 seconds before terrain impact. Considering that the flight crew might not be expecting this warning, the 60 second lead time gives adequate warning for the flight crew to react and respond.

A global terrain database with 100% coverage is resident within the EGPWS. By using the input latitude, longitude, altitude as well as flight path angle, turn rate and ground speed, the EGPWS can place the aircraft position within the terrain data and “look ahead” to potential conflicts with terrain. This eliminates the problem of abruptly rising terrain and gives greatly enhanced warning times for most CFIT situations. Software algorithms look down, based on flight path angle and nearest runway; ahead, based on aircraft ground speed; aside, based on roll angle; and up, by about 6 degrees.

Terrain Alerting

If any terrain is “seen” in the database by the algorithms, annunciators are illuminated and the voice “Caution Terrain” or “Terrain Terrain Pull Up” is given. The algorithms are designed to provide about 60 seconds advance alert to conflict with terrain. The first aural warning of “Caution Terrain” is in a more quiet or low tone so that it may be easily distinguished from the louder and more urgent callout of “Terrain!  Terrain! Pull Up!”[11]

Pop-up Feature

Another enhanced feature of the EGPWS is the ability to have the display map “pop-up” or be overlaid on the cockpit’s weather radar system so that the flight crew may have a more integrated picture of weather and terrain. Putting the two systems together with the Pop-Up feature may help eliminate errors when a flight crew member must look at two different displays in order to interpret the flight condition in relationship to terrain and weather.

Geometric Altitude

As mentioned previously, many of the CFIT accidents in prior years could be attributable to altimeter miss-sets. The EGPWS uses a geometric altitude that blends improved pressure altitude calculations, GPS altitude, radio altimeter, and terrain and runway information to eliminate the reliance on human data input. This feature alone may go a long way to reduce the number of CFIT accidents each year. One statistic claims that 25% of all CFIT accidents are attributable to miss-set altimeters.[12]

Envelop Modulation

One feature of the EGPWS is the capability to customize the alert system at certain geographical locations in order to reduce nuisance warnings and provide extra alert time if necessary.

Maintenance

In considering human factors in relationship to the maintenance of the EGPWS, automating the tasks of updating and maintenance is a prime concern of the design team. Automation should be incorporated to make a task simple to perform to achieve a more correct output. The role of human interaction should not be so difficult or tedious as to prohibit or discourage the task to be performed. The person responsible for ensuring the EGPWS is up to date and operating correctly should be able to accomplish these tasks effectively through automation.

Access to correct and updated databases is critical to flight safety. The EGPWS Terrain Database requires updates to remain the most useful to the flight crews but regulations are not in place to require such updates.   Even though not required to do so, Honeywell makes available three updates per year which they provide at no additional cost knowing that easy access to the information will help the flight crews stay informed on critical flight data.  The EGPWS operators are able to sign up for an email notification that a new database download is available. The database is available through the internet and takes only 30 minutes to complete once downloaded onto a card that interfaces with the EGPWS system.[13]

Honeywell makes available to EGPWS operators many tools to assess whether or not the EGPWS unit is working correctly. On their website the company has available a step-by-step self test guide as well as a real-time assessment of why a false terrain warning may have been activated.

With Human Factor considerations in mind the engineers worked to create a product that interfaced well between Humans and Technology. Unfortunately, it is impossible to prepare for all situations. There was one interesting problem that arose as a result of a disconnect between what the engineers designed and how avionic technicians interpreted the technological indication. An article in Avionics News stated the problem this way, “The biggest mistake technicians make when troubleshooting the EGPWS is using illumination of any cockpit failure annunciators (GPWS INOP, TERR INOP, W/S INOP) as a reason for removal.”[14]

Taking the statement on its face value, how could one fault the technicians for removing critical equipment that appeared to be indicating a failure. The Avionics News article goes on to explain the failure signal indicates a lack or failure of the required input signal and not a failure of the EGPWS unit itself. The technicians would remove the EGPWS unit and send the unit back to Honeywell for the company to test. Honeywell had so many returns of equipment in which no problems were found that they have begun to charge customers for returns of units for which no self test was performed prior to sending the units to Honeywell.

This disconnect issue was that on a different part of the display panel another indication would be illuminated to verify that the computer is fine. So if there is an INOP indication the technicians should have tried to troubleshoot via a self test procedure detailed in the manual rather than remove the equipment itself. The technicians did not make the connection between the two displays. The FAA suggests that when designing error messages the engineers should incorporate multilevel message. “The system shall provide more than one level of error messages, with successive levels providing increasingly detailed levels of explanation.”[15] If the failure indication utilized a more multilevel approach to error messages perhaps the technicians would have been able to more easily understand the failure indication thus not wasting company time in removing operable equipment.

No where in the article was it suggested that the engineers may have prevented this misunderstanding, that was quite prevalent, by considering Human Factors in the design of this failure of signal input indication.

The company does make available to EGPWS operators many tools to assess whether or not the EGPWS unit is working correctly. On their website the company has available a step-by-step self test guide as well as a real-time assessment of why false terrain warnings may have been activated which makes flight testing unnecessary. This is major cost cutting measure in terms of fuel for the operators of the EGPWS.[16]

The success of EGPWS can be measured by the number of CFIT accidents that have been prevented. To date, EGPWS has been responsible for saving 27 different aircraft from CFIT accidents.[17] One of the prohibitive factors in getting this cutting-edge technology in all aircraft is the expense. There has already been some forward movement by the US Presidential Commission on air safety to mandate that all commercial air-carriers include the EGPWS system on all their aircraft. This federal push comes from the success of a 1994 mandate in which the FAA mandated the installation of GPWS into regional turbine aircraft with 10 or more passenger seats. Since the 1994 mandate not one aircraft from that fleet of about 1600 aircraft has suffered a CFIT accident in the USA. It is unclear how a mandate to install this technology would impact the economics of the airline industry but it would be a giant step toward the goal for a zero accident rate for commercial air-carriers.

[1] EGPWS Review (2004, February) Flying magazine

[2] Federal Aviation Administration Advisory Circular  (Publication No.61-134)  General Aviation Controlled Flight Into Terrain Awareness (2003, April 1)

[3] Flight Safety Foundation Priorities. (2001-2004) Page 2 Retrieved from
http://www.flightsafety.org/

[4] Federal Aviation Administration Advisory Circular  (Publication No.61-134)  General Aviation Controlled Flight Into Terrain Awareness, (2003, April 1)

[5] EGPWS Review (2004 February) Flying magazine

[6] Karl Kraus (1874–1936), Austrian writer. Trans. by Harry Zohn, originally published in Beim Wortgenommen (1955). Half-Truths and One-and-a-Half Truths, University of Chicago Press (1990).

[7] Federal Aviation Administration Human Factors Team Report on: The Interfaces Between Flightcrews and Modern Flight Deck Systems”,(1996, June 18)

[8] The American Heritage Dictionary of the English Language, Fourth Edition, 2000

[9] Getting the Job Done-Part 1, Avionic News, March 2004

[10] Honeywell document 3.3;(2002,  January 21)  accessed from
http://www51.honeywell.com/aero/Products-Services/Avionics-Electronics/EGPWS-Home.html?c=21

[11] EGPWS Saves Lives (2004) [electronic version] Retrieved from
http://www.egpws.com/general_information/broxhures/EGPWS_Saves_Lives.pdf

[12] EGPWS Saves Lives (2004) [electronic version] Retrieved from
http://www.egpws.com/general_information/broxhures/EGPWS_Saves_Lives.pdf

[13] Honeywell document (2004, January) accessed from
http://www51.honeywell.com/aero/Products-Services/Avionics-Electronics/EGPWS-Home.html?c=21

[14] Getting the Job Done-Part 2, Avionic News, May 2004

[15] Federal Aviation Administration Human Factors Team Report, Human and Computers Interface, Error Messages, (1996, June 18)

[16] Honeywell document (2004, January) accessed from
http://www51.honeywell.com/aero/Products-Services/Avionics-Electronics/EGPWS-Home.html?c=21

[17] Honeywell document (2004, January) accessed from
http://www51.honeywell.com/aero/Products-Services/Avionics-Electronics/EGPWS-Home.html?c=21

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Human language differs from animal communication in many ways.  While humans use language to produce an infinite number of unique sentences as a form of communication, animals lack this ability.  Animals communicate by signal codes, which means they have a limited number of statements, generally as simple responses to certain situations.  As one researcher says, “…the natural sounds and gestures produced by all nonhuman primates show their signals to be highly stereotyped and limited in the type and number of messages they convey.”  Human language, on the other hand, is a true language – a system of arbitrary signs which allows us to convey unlimited interactions.

For one, human language differs because it has form and meaning, which means it has a structure which combines sounds, gestures, letters, and written words which when put together have a certain significance or meaning.  Secondly, human language differs because it is creative, meaning that we can (with language) produce (and understand) an infinite number of new sentences which have never before been spoken; we can lie and joke and even talk about things that don’t make any sense.  Thirdly, human language differs because it has displacement, which basically means that we as humans can talk about things in the past and future, and things that are either right in front of us or miles away.  While some animals, like bees, have shown signs of limited displacement, and while certain apes have been able to acquire a number of sign language messages, animal communication is restricted to very simple messages like “look out” or “danger!”  Animals cannot say “look out, I saw a snake in that tree yesterday” or make jokes, lie, and talk about the imaginary (which linguists refer to as the ability to use tropes).

Many researches have tried to teach primates language, and while some chimps and apes have been more successful than others in language acquisition, the end result has always shown that primates can only learn language to a certain extent, and usually only things related to stimulus-controlled phenomena like eating and drinking.  Language was only rarely spontaneous with these animals, they usually displayed redundancy and imitation, and no research shows them to have the same ability of language learning like a human child.  Gua was a chimp in the 1930s that was raised as a child along with the researcher’s own baby son.  Gua understood more words than the human boy at sixteen months, but never learned any more than that, while the boy of course did.  Among other things, primates have a different vocal apparatus than ours which prevents them from producing spoken language.  Research has simply shown that primates are not capable of learning human language.

Non-primates have shown an even lesser chance of acquiring human language.  Dolphins have shown the ability to understand and act on certain commands, but they have not displayed understanding for “novel utterances, metaphors, jokes, and lies.”  Not to mention the fact that producing spoken human language is simply impossible for these animals.

Like other animals, dolphins also have a limited number of messages which they produce amongst each other.  Dolphins, as well as apes and other animals have no way of communicating about the past, expressing their feelings, lying to each other, and among other things, talking smack about their enemies.  Human language, however, differs because it gives us the ability to do all of those things and more.

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The definition of a pheromone, according to the Oxford dictionary, is: “a chemical substance secreted and released by an animal for detection by another usually of the same species. ” Basically, pheromones are chemical messengers that activate physiological or behavioral responses in other like organisms. In most mammals pheromones are detected within the vomeronasal organ (VNO). In human beings, however, it is hypothesized that they are detected and processed in the olfactory bulbs within the brain. The olfactory bulbs are located near the hypothalamus, which is the part of the brain that controls sexuality.

Pheromones are actually modified hormones or molecules used in trace amounts in order to control bodily functions ranging from cell-cycle regulation to production and release of other chemicals and proteins. Most importantly, they are hormones responsible for the behavioral responses of individuals – sexual behavior included.

Where Are Pheromones Found?

Pheromones have been isolated in saliva, sweat, and urine of different species, including humans. Most mammals have a specific organ for the detection of pheromones; however, it has not yet been assessed whether the pheromonal communication depends solely on that organ. While “odorant detection is mediated by millions of olfactory sensory neurons located in the olfactory epithelium lining the nasal cavity” of the first olfactory system, “the vomeronasal organ, a separate olfactory structure in the nasal septum that opens into the nasal cavity” mediates the pheromone perception in the second olfactory system (Buck, 2004, p. 184). These two systems are very similar to each other.

It is proposed that humans can detect around 10,000 different odors and which is accomplished with the use of around 350 odorant (olfactory) receptors ,or ORs (Buck, 2004, Kien & Storm, 2004). ORs are transmembrane proteins embedded in the cell membrane of the sensory neurons or the olfactory epithelium. These transmembrane proteins are coded in the DNA and several studies show that “each neuron may express only one gene,” therefore only one type of an OR is found in the cell membrane (Buck, 2004, p.184).

How is it that humans only have 350 odorant detectors but can detect over 10,000 different compounds? The answer is that the 350 ORs have additive effects. Each OR binds to a specific chemical or odorant molecule which causes a cascading sequence of events within the cell

… one OR can recognize multiple odorants and that a single odorant is detected by multiple ORs, but, importantly, different odorants are recognized by different combinations of ORs. This indicated that the OR family is used in a combinatorial manner to encode odor identities. (Buck, 2004, p.185)

The combination of activation of several of the 350 ORs encodes a particular odor which is then passed trough the olfactory bulb to the olfactory cortex.

The second system that uses the VNO has a similar processing pathway. There are between 120 and 140 receptors in the VNO in mice – significantly less than around a 1,000 found in the olfactory epithelium of mice (Buck, 2004). This is a general trend in most mammals. There are usually two families of receptors: V1Rs and V2Rs – vomeronasal receptors which are not to be confused with the olfactory receptors. These receptors are similar in form and function to the ORs and can detect a variety of chemicals. Once pheromones are detected by vomeronasal receptors “sensory signals are relayed from this organ [VNO] through the accessory olfactory bulb and then targeted to the medial amygdala and hypothalamus, areas implicated in the hormonal and behavioral effects of pheromones” (Buck, 2004, p.184). One major difference between the two systems is that while a few of the vomeronasal neurons equipped with VRs can detect more than one pheromone, most neurons that can detect only one pheromone – a single receptor-type pheromone indicating a lock and key mechanism (Buck, 2004, Von Campenhausen, 2000).

How Many Types of Pheromones Exist?

Pheromones are essential to nonverbal communication between members of the same species. Human beings are, however, unaware of pheromones and the influence they have on the mating process as well as other areas of life. Pheromones play significant roles in the areas of relationships and reproduction. There are four main types of pheromones; releaser pheromones, primer pheromones, signaler pheromones, and modulator hormones. Releaser pheromones elicit an immediate response that is quick and reliable. Primer pheromones require more time than releaser pheromones to affect their intended. Signaler pheromones provide information and modulator pheromones can both alter and sync bodily functions.

Releaser pheromones are generally associated with sexual attraction. Primer pheromones affect the development or reproduction physiology, including puberty, cyclicity in females, the success or failure of pregnancy, and shifts in hormone levels (Wysocki & Pereti, 2004). It has been hypothesized by Wysocki & Pereti (2004) that in other mammals, if a female is exposed to male pheromones from a male other than the one who impregnated her, primer pheromones can cause the pregnant female to spontaneously abort the fetus. Signaler pheromones allow human mothers to recognize their newborns by scent alone. Fathers who attempt this sameprocedure fail. The signaler pheromones give us our genetic odor print, which is as unique as a fingerprint. Modulator pheromones, in the form of sweat, when placed on the upper lip of females shifted the mood of the subject. They were more relaxed and less tense than the control group, and they also have an impact on women’s monthly cycle.

Of these four types of pheromones there are also four specific functions of pheromones: opposite sex attractants, same sex repellents, mother infant bonding, and menstrual cycle modulators. Pheromones activate specific regions within the brain. They affect social behavior, regulate ovulation, and modulate physiological parameters such as the serum levels of testosterone, luetinizing hormone and follicle stimulating hormone. Pheromones have also been shown to affect respiration and cardiac frequency in a gender specific way (Beier, K. , Ginez, I. , & Schaller, H. , 2004).

1 – Introduction to Pheromones

2 – Opposite-Sex Attraction

3 – Same-Sex Attraction

4 – Mother-Infant Bonding

5 – Menstrual Cycle Modulator

6 – Conclusion & References

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Ponty then goes on to discuss more specifically why physiology alone, or why psychology alone cannot account for the phenomenon of phantom limbs. Rather Ponty attempts to understand how each complements the other; the body the mind and the mind the body.

He begins with the example of a man who has lost his leg. Stimulus is applied to, instead of the leg, the path between the stump and the man’s brain. It is then realized that the man will experience, once again, the feeling of his leg. Why is this? Ponty begins with the physiological, mechanistic approach, but soon reveals its shortcomings.

“What has modern physiology to say about this [phenomenon]? Anesthesia with cocaine does not do away with the phantom limb, and there are cases of phantom limbs without amputation as a result of brain injury. Finally, the imaginary limb is often found to retain the position in which the real arm was at the moment of injury” (428). This leads Ponty to the conclusion that physiology alone cannot account for this phenomenon; the psychic realm must also play a role.

He believes the phenomenon of phantom limb can be understood more completely if we are able to understand a similar phenomenon, that of anosognosia. Anosognosia is the phenomenon that occurs when a patient retains a limb, but refuses to acknowledge its presence. Ponty explains these patients “who systematically ignore their paralyzed right hand, and hold out their left hand when asked for their right, refer to their paralyzed arm as ‘a long, cold snake’, which rules out any hypothesis of anesthesia and suggests one in terms of the refusal to recognize the deficiency” (428). This phenomenon clearly demands a psychological explanation. But is a psychological explanation enough to account for phantom limbs? Ponty doesn’t think so: “…no psychological explanation can overlook the fact that the severance of the nerves abolished the phantom limb. What has to be understood, then, is how the psychic determining factors and the physiological conditions gear into each other.”

But this phenomenon cannot be understood simply as a combination of the psychic and the physical forces. It must be understood in terms of the person, as the living body rising toward the world with its various projects in mind as it does so; it must be understood as the relationship between the subjective person and the objective world.

Ponty then applies this view of the subject/object to the physiological and psychological explanations, pointing out their essential shortcomings. Along the way he begins to borrow an idea from psychoanalysis, the idea of repression. A purely physiological explanation of anosognosia and the phantom limb could be conceived of as the repression of what Ponty calls “interoceptive” stimulations. According to this idea, anosognosia would be the “absence of a fragment of representation which ought to be given, since the corresponding limb is there; the phantom limb is the presence of the part of the representation of the body which should not be given, since the corresponding limb is not there” (430). But this makes no sense, if a part does not exist it should not be represented, and vice versa. But the psychological account doesn’t do much better.

In the psychological account, the phantom limb is viewed as a memory or a perception, while anosognosia is forgetfulness or a negative perception. In this case the phantom limb is viewed as an actual positive perception of an entity which does not exist, while anosognosia is thought of as the absence of an actual presence, which, again, makes little sense.

Ponty resolves these issues by realizing that in both cases we are relying on the outside world and its inherent characteristics, which is problematic. He says, “In both cases we are imprisoned in the categories of the objective world, in which there is no middle term between presence and absence. In reality the anosognosic is not simply ignorant of the existence of his paralyzed limb: he can evade his deficiency only because he knows…what he does not want to face, otherwise he would not have been able to avoid it successfully” (430).

This is a critical point Ponty is trying to make. Just as in the psychoanalytic tradition, the patient can only be aware of and act on the basis of what he or she knows. In the case of the phantom limb patient and the anosognosic, each is aware of the deficiency and is attempting to make up for it on what could be considered the subconscious level. The anosognosic denies knowledge of the paralyzed limb in order not to feel the pain of the handicap, while the phantom limb patient demands that his exists for the same reason, so as not to be rendered handicapped.

This is what Ponty means when he says, “The phantom arm is not the representation of the arm, but the ambivalent presence of the arm” (430-431). There is no deliberate decision made by the patient to deny existence or assert existence (depending on the case), but it comes from something deeper. Ponty says that it finds its genesis elsewhere, not in the patient declaring: “I think that…”, but it needs-to-be for the patient.

This idea hinges on the aforementioned projective outlook of the living-body toward the world. The living-body views the world in terms of projects it wishes to accomplish, and to do this the body becomes unperceived as it learns to perform certain skills. The body, in this sense, is comprised of two layers: the habitual and the present. The habitual is that which we have learned to do and can do without thinking (turning a doorknob or tying a shoe). These skills are put at the disposal of the present body, and because one does not have to think about them, to bring them into the present body, they do not intrude upon the present body. When, as a young child, one learns to turn a doorknob, this becomes part of the habitual body and can be utilized by the present body.

The problem approaches when something interrupts this transmission from habitual body to present body, i.e. a disfigurement or a handicap. In this case, an amputated arm for example, the present body can no longer rely on the habitual. The tying-of-the-shoes becomes impossible, as well as the opening-of-the-door. This causes great pain for the patient and may result in the phenomenon of phantom limb or anosognosia, as a way for the patient to continue it his or her existence. The patient never really deals with the situation, but covers it up somewhat; thus the analogy to psychoanalytic repression.

So here we can come to understand that a merely physical or psychological explanation of the phenomenon of phantom limbs or anosognosia are lacking. The patient must be viewed as occupying a middle ground between the two. He builds a self through his past and relies on it in the present and in toward a future horizon. When this reliance is disturbed through a handicap, the patient must act (or not act) in someway so that he may continue in his existence. Often this results in a repression of the malady so that the patient believes he will continue on his same path, relying on his past and directing his living-body toward the future.

Citations

Mooney, Timothy & Moran Dermot, eds. The Phenomenology Reader. Routledge Publishing, London and New York. 2004. (Reprint of The Body as Object and Mechanistic Pysiology)

Related

Thriving in cold polar seas, volcanic springs more than 100°C, and even highly acidic solfataric fields, extremophiles can call any place on this planet their home. Extremophiles live life on the edge of what is considered the norm, having adaptations to extreme pressure, pH, salinity, and temperature (2). There are wide varieties of extremophilic organisms inhabiting virtually every point on the globe; however, the majority of these are Archean (2). Extremophiles can be broken down into groups based on which particular biotype they thrive in. Thermophiles thrive at very high temperatures, while psychrophiles live in very cold environments (2). Alkaliphiles can live at high pH, while their acidophile counterparts have an optimum pH at levels much lower than neutral (2). Also, there are halophiles who live within extremely high salt concentrations, and piezophiles who can live at pressures much higher than one atmosphere (2).

Thermophiles are perhaps one of the most interesting varieties of the extremophilic organisms. These microorganisms are those that can thrive at temperatures over 50°C (9). Based on their optimal temperature, thermophiles can be subdivided into three groups: slight thermophiles with an optimal temperature between 50°C and 64°C and a maximum at 70°C, extreme thermophiles with an optimal temperature between 65°C and 85°C, and finally hyperthermophiles with an optimal temperature above 85°C and a maximum above 90°C (9). (For the purposes of this paper, the term “thermophile” will refer all organisms with the ability to thrive at temperatures above 50°C, unless otherwise noted.) It was previously believed that life could not thrive at temperatures above 113°C, however recent discoveries have found a microbe called strain 121 that is able to grow at 121°C and can survive at 130°C (1). This changed the way many scientists look at the temperature dependence of life.

As of 2001, over sixty species of Bacteria and Archea have been isolated and grown between 80°C and 110°C (9). Of the thermophiles, there are a much higher number of anaerobes than aerobes. This is most likely due to the fact that oxygen is much less soluble at higher temperatures and therefore is not available for organisms to use in metabolic processes (9). Thermophiles can grow in both terrestrial and marine environments, including: solfataric fields, geothermal soils, volcanically heated surface waters, hot fumaroles, deep-sea vents, and even black smokers (2). These can also thrive in biotopes created by man, such as smoldering coal refuse and geothermal powerplants (2).

Due to the hazards of living at such extreme temperatures, thermophiles have evolved a variety of mechanisms that allow them to survive at temperatures no other organisms can thrive at. These traits include unique membrane lipid composition, thermostable membrane proteins, and higher turnover rates for various protein enzymes (9). One of the most important attributes to the maintenance of homeostasis within the organism is that of the plasma membrane surrounding the organism. Archaean thermophiles, and also acidophiles, have membranes containing unique ether lipids (2). These tetraether lipids span the entire membrane forming a rigid monolayer that is impermeable to both ions and protons (2). Ether-type lipids, such as these, are much stronger than the ester-type lipids found in non-thermophilic Bacteria and Eukarya (2).

Also, the lipid composition in the membranes of the thermophiles consists of more branched and saturated fatty acids than other organisms (9). Having a stronger lipid complex within the membrane helps the Archaean thermophiles to withstand higher temperatures better than other organisms. Aside from having to stabilize the plasma membrane at high temperatures, thermophiles must also stabilize their proteins, DNA, RNA, and ATP. As of now, the process of heat stabilization for DNA, RNA, and ATP is unknown (2).

Thermophiles have developed distinct ways of heat stabilizing the proteins that are required for the maintenance of life. For one, the surface energy of the protein, along with the hydration of the non-polar groups that are exposed, are minimized (2). Also, hydrophobic regions are packed into a very dense core of the protein by charge-charge interactions between amino acids (2). There is also an increase in salt bridges and other networks, which help to stabilize the structures at higher temperatures (2). Finally, it has been shown that there is a distinct increase in the synthesis of chaperonin proteins after a heat shock (2). Chaperonins are proteins that unfold and help refold proteins that are not folded properly enough to perform their required function (4). Increasing the number of these during high temperatures, most likely allows the cells to have second chance at folding proteins that misfolded due to high heat (2).

Another group of extremophiles that have adapted themselves to an extreme environment are the halophiles. These organisms have the ability to grow at very high salt concentrations (2). In this case, the salt concentrations can be anywhere from 3% to 35% (2). Commonly, this group of extremophiles can be found in such environments as sea water, hypersaline lakes (the Dead Sea, the Great Salt Lake), and saline souls (2). Halophilic organisms can also be found in man-made saline environments such as salted foods and tanned hides (2). Much like thermophiles, halophiles can also be broken down into three different groups; instead of optimum growth temperature, the groups are based on optimum salinity. There are slight halophiles that grow at an optimum salinity 2% to 5%, moderate halophiles that grow at an optimum salinity of 5% to 20%, and finally extreme halophiles that grow at an optimum salinity of 20% to 30% (6). Also, some organisms are referred to as “halotolerant,” meaning that the organism has the ability to grow in bother hypersaline environments and non-saline environments, but saline is not required for optimum growth (6).

An interesting feature of hypersaline environments is the formation of gradients in concentration with respect to time. As small bodies of hypersaline waters evaporate, the salinity gradually increases. The salinity of water can start at 1M NaCl, but as times goes by the salinity can increase to over 5M NaCl (6). This causes natural fluctuations in the halophilic species that inhabit that particular body of water. For example, when water is around 1M to 3M NaCl, the environment tends to be filled with algae, protests, and yeasts (6). However, when evaporation occurs, and the salinity increases 5M, those organisms die off because they cannot survive at such high salt concentrations. Organisms that can survive at these higher salt concentrations, such as red-orange halobacteria, drastically increase in numbers until the body is completely dried up or diluted back to a lower concentration (6). The increases in red-orange halobacteria populations are very dramatic and blooms can be as dense as 10^8 cells per mL (6). However, no matter what level of salinity the organism can thrive at, all halophiles face difficulties in surviving.

One of the biggest problems faced by halophiles in maintaining homeostasis is the balance of osmotic pressure. Since these organisms are in hypertonic solution, water diffuses out of the cells and into the surrounding environment. This even would cause non-halophilic organisms to plasmolyze or, if the organism does not have a cell wall, the organism would shrivel. Both of these reactions would be lethal to the organism (4). Usually, the organism would take up sodium ions to create equilibrium between the interior and the exterior cellular environments. However, since sodium ions at such high concentrations would be potentially lethal within a cell, most halophiles accumulate potassium ions while actively expelling sodium ions to create osmotic equilibrium (2). Aside from potassium ions, halophiles also accumulate other non-disruptive solutes to maintain equilibrium. These can include amino acids, glycine, betaine, ecotine, and sucrose (6).

Other problems faced by halophiles include: protein structure and membrane structure. In order to combat denaturation, aggregation, and precipitation of proteins at high salt concentrations, halophiles proteins often contain a high ration of acidic to basic amino acids, thus giving the surface of the proteins a negative charge (6). It is believed that this negative charge allows the proteins to be solvated in a high salt environment (6). Halophile membranes are unique in their composition, just as thermophiles are. Some halophiles make use of the protein bacteriorhodopsin (6). This compound of bacterioopsin and retinal is found in the membranes of some halophiles in lattice shaped areas, giving the membrane a purple color and sometimes covering more than 50% of the entire membrane surface (6). The function of this protein is to act as a light dependant proton pump (6). When induced by a drop in oxygen levels or a high intensity of light, this protein can help support phototropic growth (6). Halophiles also have novel gas vesicles to allow flotation of the organisms in liquid and into higher depths where more oxygen may be available, or where the salt concentration is at optimum range (6).

Another form of extremophilic living is the ability to live in pH levels lower than neutral. Organisms that inhabit the niche between pH 0 and pH 4 are termed acidophiles (2). These organisms often have the ability to grow at high temperatures as well; organisms that can do as such are called thermoacidophiles (2). Acidophiles can inhabit any niche within the bounds of low pH, however the only one genus is known to thrive at pH 0; the genus Picrophilus has the uncanny ability to grow aerobically at 60°C and at pH 0 (8).

Living at such low pH’s is not easy, so acidophiles have evolved ways to overcome the difficulties. For one, the internal pH of the cell is maintained as close to neutral as possible, usually between pH 5 and pH 7, n order to avoid the denaturation of proteins and other molecules (8). However, Picrophilus oshimae has been recorded as having an internal pH of 4.6 (8). Also, the cellular membranes have a very low protein permeability to keep stray protons from an acid out of the cytoplasm (8). In order to maintain the internal pH, acidophiles either actively excrete protons or use them in various metabolic reactions such as the reduction of oxygen in the membrane, before the acidic protons can cause internal cellular damage (8). Acidophiles also utilize non-energy processes to maintain internal pH. These include the maintenance of fixed negative charges on intracellular molecules and the upkeep of a proton diffusion potential (8). Protein enzymes must also be modified in order to keep from being denatured. Acidophilic enzymes have the charged amino acids replaced by neutral polar amino acids in their polypeptide chains (8). This reduces the electrostatic repulsion that occurs between charged groups at low pH, thus enhancing stability (8).

Living at the opposite end of the spectrum from acidophiles are alkaliphiles. These organisms thrive in environments with a pH between 10 and 12, with an optimum growth pH of about 9 (7). Alkaliphiles also have the ability to live in neutral and even acidic environments (7). Of interesting note, is the fact that when alkaliphiles are placed in a neutral or acidic environment, they have the ability to change the environmental pH to a more optimal level (7). In order to survive at these levels, alkaliphiles have novel adaptations to cell wall structure. It has been shown that the cell wall of alkaliphiles contains a variety of acidic compounds, including: phosphoric acid, aspartic acid, galacturonic acid, glutamic acid, and gluconic acid (7). Having these negatively charged amino acids in the membrane allows the cells to better absorb sodium ions and hydronium ions (due to their positive charges),while at the same time repel the hydroxide ions which are in high concentrations at high pH levels (7). Having a membrane capable of this feat allows alkaliphiles to grow at pH levels higher than any other organism.

A final type of extremophilic organism is the group called piezophiles. Piezophiles are organisms that have the ability to grow at pressures higher than normal atmospheric pressure (10). The majority of piezophiles can also be categorized by the temperatures where they thrive: thermopeizophiles grow in high temperatures and pressure while psychropeizophiles grow in low temperatures and high pressure (10). Piezophiles are found underwater, at virtually all depths. Depending on the location of their underwater home, piezophiles are subjected o different temperatures. For example, the thermopiezophiles would be found around deep-sea vents (10). As for how these organisms have the ability to survive at high pressure, it has been difficult for scientists to show how piezophiles overcome this extreme. However, scientists are beginning to look at the cell membrane to see if piezophiles have a unique membrane composition or structure that would allow them to survive at the greatly increased pressures (10).

Thermophiles, halophiles, acidophiles, alkaliphiles, and piezophiles all take life to the extreme. By studying these unique organisms, scientists can gain insight into how life arose on the Earth and even infer as to how life would be able to exist on other planets. According to professor Michael Danson, a biochemistry professor at the University of Bath in the UK, “By studying how organisms live and thrive in places like the Antarctic, if we can understand how these organisms operate, then we will have a good starting base by which to find life and study life on Europa” (3). As for the origins of life on Earth, some scientists are looking to the extremophilic microbe Dienococcus radiodurans. This extremophile has the unique ability to survive radiation at several thousand times the lethal dose for humans (5). Researchers in St. Petersburg attempted to induce this type of radioactive resistance in E. coli. They subjected the bacteria to gamma rays to kill 99.9% of the population. After allowing he survivors to recuperate, they repeated the cycle. After 44 cycles of gamma radiation, it took 50 times the original dose to kill 99.9% of the population (5). Using their data, they found that it would take thousands of these cycles before the E. coli were as resistant to radiation as the Dienococcus. They have calculated that it would take somewhere between one million and a hundred million years for Dienococcus to have acquired this resistance on Earth (5). However, these researchers feel that if this microbe had evolved on Mars, it would have been able to acquire this level of resistance in a much more reasonable time due to the amount of radiation that Mars’ surface is subjected to (5). However, it has not yet been shown that this organism did evolve this ability from living on Mars, as of now it is merely a story.

Stories like the previous are bound to appear. Extremophiles have found a way to fill niches on Earth that no other organism can even fathom to survive in- showing that life will find a way to survive almost any conditions it happens to find itself. The environments on Mars and Europa are not a far step from the extreme locales here on Earth. The variety of unique adaptations that extremophiles here on Earth have developed could very well translate to other worlds. By continuing to study these organisms, scientists will continue to discover just how extreme life really is.

Works Cited

1. (2003) Some like it hotter. Science News. 163(123), 366.
2. Antranikian, Garabed. (January 2001). Extremophiles. In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.
3. Black, H. (2002). Extremophiles: They love living on the edge; these microbes, with possible ties to outerspace, call fire and permafrost home. The Scientist. 16(14), 36-37.
4. Campbell, Neil A., and Reece, Jane B. (2002) Biology (6^th ed.). San Francisco: Benjamin Cummings.
5. Clark, S. (2002). Did living on Mars build up a microbe’s resistance to radiation?.
   New Scientist. 175(2362), 16.
6. DasSarma, Shiladity, and Arora, Priya. (July 1999). Halophiles. In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.
7. Horikoshi, Koki. (April 1999). Alkaliphiles. In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.
8. Norris, Paul R. (March 2001) Acidophiles In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.
9. Weigal, Juergen, and Canganella, Francesco. (October 2000). Extreme Thermophiles. In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.
10. Yayanos, A. Aristides. (December 2001). Barophiles and Peizophiles. In: Nature Encyclopedia of Life Sciences. London: Nature Publishing Group.

Related

The rise and development of humankind is the primary source for the mass extinction that occurs today. From the times of Jesus until the year 1800, man contributed to the loss of one species every 55 years. This statistic could almost be considered natural, but then should be taken into account the later years. From 1800 to 1900, one species was sacrificed by and for mankind every 1.5 years. Between 1900 and 1990 that number rose to one lost species every year. The years between 1990 and 1995 contained a surge in population and use of resources and in effect killed 3 species each day. Today, the number is ever rising.

A rapid growth in human population has strained the Earth’s resources as well as its species. Around 40 to 50 years ago, the population of the world was about two billion. Today, that number is over six billion. The estimated population in the year 2030 is eight billion, which seems to be more than our planet is capable of handling under the current abusive circumstances. Most of the Earth’s resources are not able to be replenished and so will continuously deteriorate as the human population continues to escalate in its demand for them. These same resources also provide food and shelter for the animals which are or would become endangered; as the supplies of Earth are used up, the endangered species become extinct.

In addition to the problems of resource abuse, poaching, and habitat destruction, the introduction of exotic species into new habitats is one of the major factors that contributes to the loss of so many species that were native to that land. For example: in California, trout were introduced into a previously-fishless body of water to heighten the fishing industry. The effect of this decision, however, was the rapid decline in the population of frogs and other amphibians which lived in the immediate area. The best explanation reasons that the fish eat the frogs’ eggs and tadpoles, thus cutting off the lives of the amphibians before they have a chance of survival. Millions of dollars have been spent to eliminate non-native species from environments such as this to preserve the native species and ecosystems. Hopefully, the amount of money working against exotic species will discourage species displacement.

It is a proven fact that the diversity of species is the most important factor in the survival of an ecosystem. Pollinators, such as bees, help plant-life reproduce by transferring pollen from one flower to the next. These plants provide food for herbivores such as rabbits and deer. The herbivores’ numbers are kept in-check by their predators, the carnivores, which include wolves and big cats. In this way, neither the plants nor the herbivores are allowed to multiply exceedingly, and a balance is achieved. When this cycle is interrupted, however, and one species is lessened or completely removed, the results would be catastrophic to the species that are involved in even the least direct way. Half of the world’s diversity in species is contained in rainforests, which once covered 25% of the earth’s surface. Through the ravaging by mankind and through the afore-mentioned effects, however, they now cover merely 6%, and are growing thinner every day.

There are those who argue that the extinction of species is not a matter that needs immediate attention. The fact that some species that were once presumed extinct have resurfaced is very true; the cases of the black-footed ferret and Edward’s pheasant are only two in hundreds of such revivals. The problem, however, does not lie in the complete extinction of a certain species; the mere deterioration in a species’ population is enough to upset the ecological balance of a system. No one can tell for sure whether the last of any species has died; humans cannot feasibly scour the earth for a survivor. We can, however, notice when a species that was once abundant falls to a mere handful due to human intervention.

Some skeptics continue to argue that environmentalists are keeping the natural extinction processes at bay by attempting to save endangered species. The current extinction rate, however, ranges from 1000 to 10,000 times higher than natural extinction rates. This number is very alarming when the health of the ecosystem is taken into consideration. If the world continues on the path it is on now, two million species of plants and animals will be extinct by the end of this century.

There is an ethical duty to endangered species that lies within mankind. Species that become rare or extinct have an effect on other species, including humans, if only in an indirect way. By destroying resources, poaching, and ultimately rearranging the ecosystems of the world, humankind is in actuality playing God. No one can argue that we are qualified to do so. Man has the power to stop the chain reaction that is happening all over the Earth, and a deep responsibility exists to correct our own mistakes.

There are efforts in place to assist in the fight against extinction. In 1973, President Nixon signed the Endangered Species Act, which proved that the United States Congress recognized the plight of endangered species and the importance of saving them from extinction. By placing endangered animals on a protective list that made destroying these animals and their habitats illegal, these species were given the chance to multiply and regain the population they once had. In the years since the passing of this Act, nearly 1,000 endangered species of plants and animals have been placed on the list, and more than 40 percent of these are stable or improving. The Act is not perfect, however; there is a lack of enforcement of the laws it stresses, and so it is not as effective as originally intended.

Wildlife Reserve Networks are also being used to keep animals isolated from human civilizations and possible harm. These networks include three or more areas of untouched wilderness that span as wide as a population of a given species and are protected against human entry. Corridors connect these areas to allow for migration, and are also blocked off from humans. This system of zones allows humankind and endangered animals to share the land and resources without one taking advantage over the other.

Another solution, often called a last resort, is captive breeding. Endangered animals that are on the brink of extinction are captured and bred under sterile and stable conditions to ensure healthy offspring. These captive-bred animals then must be reintroduced into the wild in order to increase the population of that species. This, however, is a task that is seldom achieved to expectations. Animals that were raised in captivity are not prepared for the harsh wilderness and so have a smaller probability of surviving their first year on their own. The option of captive breeding is often the only one available; The efforts continue.

All species of plants and animals play a part in its fragile ecosystems and natural balance. No matter how small that part is, one species’ extinction could cause a chain reaction that could devastate the world as we know it. In order to help them, the Endangered Species Act must be taken as seriously as any other document of law. Punishments should be harsher and the tolerance level should remain unwavering and strict. The zones and passages in Wildlife Reserve Networks should be better protected; poachers still enter these areas and continue to destroy the endangered species that thrive within. Finally, the captive-breeding programs in zoos and other wildlife facilities should continue, and hopefully research will unveil a way to reintroduce these animals without worry of survival.

The world is a ship in treacherous waters, and the species that live on its surface are the only rivets holding the vessel together. Mankind has the power to choke the decline of populations, and there is yet more that can be done to save this ship from sinking.

Helen Cothran, ed., Opposing Viewpoints: Endangered Species (San Diego, C.A.: Greenhaven Press, Inc., 2001)”Total Midyear Population of the World: 1950-2050,” International Programs Center, US Census Bureau, http://www.census.gov/ipc/www/idb/

James P. Sterba, ed., Earth Ethics: Environmental Ethics, Animal Rights, and Practical Applications (Eaglewood Cliffs, N.J.: Prentice-Hall, Inc., 1995)

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The purpose of this lab was to identify an unknown mixture of two compounds using powder diffraction techniques combined with scanning electron microscopy and the “PC Identify” computer software. The X-ray powder diffraction pattern of the unknown mixture was analyzed on the computer in the laboratory. A peak search-match showed possible compounds contained in the mixture for further identification. An elemental analysis was conducted using a scanning electron microscope to determine which elements were present in the unknown mixture. Information from the XRD pattern and the elemental analysis helped identify the two compounds in the unknown by comparing it with the powder diffraction files. It was determined that unknown mixture mx3 contains potassium bromate (KBrO₃) and nickel oxide (NiO). The two compounds were verified using the “PC Identify” computer software.

Introduction:

Similar to the past week’s labs, this particular lab employed the use of powder diffraction techniques to identify an unknown material. In X-ray diffraction, specimens are powdered so that all orientations are uniformly represented. X-rays are electromagnetic radiation of wavelength 0.5-2.5 A, and occur in the electromagnetic spectrum between gamma-rays and ultraviolet light. In this experiment, a monochromatic source of X-rays was used. The X-ray powder diffraction technique is used to fingerprint crystalline materials and determine their structures. Each crystalline solid has a unique characteristic XRD powder pattern. Once a material is identified, X-ray crystallography can be used to determine its structure. In this experiment, an unknown mixture of two compounds was identified. The X-ray powder diffraction pattern of the unknown mixture was a superposition of each compound’s individual XRD pattern. By examining the XRD powder pattern with a peak search-match, the computer found possible compounds in the unknown mixture for further identification.

In the second part of the lab, scanning electron microscopy (SEM) was used to conduct an elemental analysis of the unknown mixture. The SEM uses electrons instead of light to form an image. A beam of electrons is produced at the top of the microscope by heating of a metallic filament. The electron beam follows a vertical path through a column of the microscope. The electron beam travels through electromagnetic lenses which focus and direct the beam down towards the sample. Once the beam hits the sample, either backscattered or secondary electrons are ejected from it. The interaction of the electrons in the SEM with the sample results in the generation of characteristic X-rays. Detectors collect the secondary and backscattered electrons, along with the characteristic X-rays, and convert them into a signal that is sent to a viewing screen producing an image. This process was used to determine the individual elements in the unknown mixture. For unknown mixture mx3 the elements detected were potassium, nickel, bromide, and oxygen.

In the third part of the experiment, the information from the elemental analysis and XRD pattern were used along with the powder diffraction files to determine the two compounds in the unknown. It was determined that unknown mixture mx3 contains potassium bromate (KBrO₃) and nickel oxide (NiO). This result was verified with the “PC Identify” software.

Experimental Procedures:

Part One: Powder Diffraction

The first steps to this experiment included logging into the X-ray diffraction computer program in the laboratory, choosing an unknown mixture of two compounds, and downloading the XRD powder pattern intensity graph. The intensity graph was optimized by stripping away the Ka₂ and smoothing the peaks. A chart of the d-spacings, relative intensity and scattering angle of the unknown mixture was created. D-spacing labels were applied to the graph. The graph and chart were printed and saved for later use. A peak search-match was done without restriction to find all possible compounds that might be in the mixture. These were recorded and taken to the scanning electron microscopy room.

Part Two: Scanning Electron Microscopy

The SEM was used to conduct an elemental analysis of the unknown mixture. The day this lab was conducted, Thursday October 13, 2005, the SEM was not working properly. Mr. Al Stewart ran the experiment earlier that morning and gave us his results. First a picture was taken of the sample. This picture is in the appendix and labeled Figure One: Scanning Electron Microscopy of mx3. Next, an elemental analysis of the mixture was carried out. Each compound in the mixture was analyzed by placing an “X” on it and EDEXing. On the resulting graph, the strong peaks show which elements are in each compound.

Part Three: Identification

The elemental information from part two was used with the diffraction data from part one to correctly identify the two compounds in the unknown. The diffraction data used to determine the compounds included the d-spacings, relative intensities and scattering angles. This information was compared with the powder diffraction files. In unknown mx3, the compounds were identified as potassium bromate and nickel oxide. The intensity graph from part one was re-opened. This time when trying to identify the unknown on the computer, the elements resulting from part two of the lab were set as restrictions. The “PC Identify” software verified the two compounds in the mixture. The computer also identifies which peak belongs to which compound on the XRD pattern. Powder diffraction files were used to determine which peak coincides with each compound. The crystal structure, lattice parameters, and space group for each compound were determined. Finally, the measured experimental relative intensities of each compound were compared with the theoretical data found in the powder diffraction file. An error analysis was completed on the results.

Results/ Calculations:

In part one, an unknown mixture’s XRD pattern was downloaded and analyzed. Several possible compounds resulted from the peak search-match. Among these were potassium bromate, nickel oxide and several others. The original experimental data is attached at the end of this lab.

In part two, first a picture of the sample was taken. This picture is located in the appendix and labeled Figure One: Scanning Electron Microscopy of mx3. An elemental analysis was conducted and revealed that the elements in the unknown mixture were potassium, bromide, nickel and oxide. This data is also in the appendix and labeled Figure Two: Elemental Analysis of mx3. Next, each compound in the mixture was analyzed. The results from the first compound are shown in Figure Three: Compound One. The strong peaks show that this compound consists of bromide and potassium. The results from the second compound are shown in Figure Four: Compound Two. The strong peaks indicate that this compound contains nickel and oxygen.

In part three, a comparison of the d-spacings, relative intensities and scattering angles to the powder diffraction files, allowed identification of the two compounds as potassium bromate and nickel oxide. This result was verified with the “PC Identify” software in the laboratory.

Nickel oxide is rhombohedral and has theoretical lattice parameters of a = 2.9552 A and c = 7.2275 A. The space group of nickel oxide is R3m. On the mixture’s XRD pattern, NiO has peaks at (101) and (012). Potassium bromate also has a rhombohedral crystal structure. Its theoretical lattice parameters are a = 6.014 A and c = 8.156 A. The space group of potassium bromate is R3m. On the mixture’s XRD pattern, KBrO₃ has peaks at (101), (012), (110), (003), (021), (202), (113), (211), (104), (122), (300), and (024). The (hkl) for each compound are labeled on the mixture’s XRD powder pattern in the appendix in Figure Five: mx3 XRD pattern with labeled (hkl).

The PDF card file for each compound is in the appendix labeled Figure Six and Figure Seven. The measured relative intensities for each compound were compared with the card file for the compound and an error analysis was conducted. The results are in the next two tables.

Table One: Comparison of Relative Intensities for Potassium Bromate

Table Two: Comparison of Relative Intensities for Nickel Oxide

Discussion:

The information from the X-ray powder diffraction and the scanning electron microscopy allowed for us to identify the compounds in the unknown mixture. This information was verified with the “PC Identify” computer software. We were able to identify the compounds and then determine each compound’s crystal structure, (hkl) values, lattice parameters and space group and compare the relative intensities of the experimental and theoretical data.

For the nickel oxide compound, the experimental relative intensities were very similar to the theoretical ones. However, for the potassium bromate compound, the experimental relative intensities varied greatly from the theoretical data. This may have resulted from either systematic or random errors. For example, a random error may have occurred in the counting statistics. This is the probability of the event occurring and is a measurement error. The scattering angle, theta, may not have been read properly. This is another example of a random error. The differences in relative intensity may also have been caused by a systematic error. For example, the scattering angle, theta, may not have been properly set to scale. Also, the mixture might have had a low “Z” value. In this case, the X-rays will just penetrate through the thin sample.

Summary:

The purpose of this lab was achieved. Two compounds in an unknown mixture were identified using powder diffraction techniques, scanning electron microscopy and the “PC Identify” computer software. The unknown mixture’s XRD powder pattern was downloaded from the computer and analyzed. Possible compounds in the mixture resulted from a peak search-match on the XRD powder pattern. The scanning electron microscope was used to examine the unknown mixture again and identify which elements were contained in it. Comparing the d-spacings, relative intensities and scattering angles from the XRD powder pattern to the PDF powder diffraction files helped identify the two compounds in the unknown mixture, along with the elemental analysis. It was determined that the two compounds in unknown mixture mx3 were potassium bromate (KBrO₃) and nickel oxide (NiO). These compounds were verified using the “PC Identify” software.

After identifying the compounds, we were able to determine each compound’s crystal structure, (hkl) values, lattice parameters and space group, and then compare the relative intensities of the experimental and theoretical data. The experimental relative intensities for the nickel oxide compound were very similar to the theoretical ones. However, for the potassium bromate compound, the experimental relative intensities varied greatly from the theoretical data, which may have been the effect of either the random or systematic errors described earlier.

Since the scanning electron microscope was not working Thursday October 13, 2005, we may want to retry part two on our own. This way we will be confident in using the SEM for future work.

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