Roxanne Khamsi Is appreciation of music a uniquely human trait, or does any animal with decent hearing prefer pleasant combinations of notes? Cognitive scientists have discovered that tamarin monkeys have no taste for the consonant tones that mostly make up music, suggesting that musicality may be restricted to humans alone. Consonant tones are combinations of sound waves whose wavelengths are simple multiples of each other. The sounds overlap to create a smooth waveform that is pleasing to our ears. But dissonant sounds are produced when the wavelengths are very slightly different, so the two waves come in and out of phase, creating an unpleasant, jarring noise. For years, scientists have sought to explain why we prefer consonant sounds to dissonant ones. One theory is that our dislike of dissonance is related to the sensation of 'beats' that occur when the notes interfere. Previous research has shown that macaque monkeys and songbirds can tell the difference between consonant and dissonant sounds1. But the question of whether or not animals actually prefer consonant tones has been unanswered, until now. ©2004 Nature Publishing Group

Keyword: Hearing; Evolution
Link ID: 6565 - Posted: 06.24.2010

Cell replacement therapy offers a novel and powerful medical technology. A type of embryonic stem cell, called a neural crest stem cell, that persists into adulthood in hair follicles was recently discovered by Maya Sieber-Blum, Ph.D., of the Medical College of Wisconsin, Milos Grim, MD Ph.D., of Charles University Prague, and their collaborators. The discovery – reported recently in Developmental Dynamics, a journal of the American Association of Anatomists published by John Wiley & Sons, Inc. – may in many instances provide a non-controversial substitute for embryonic stem cells. Embryonic stem cells are unique, because they can differentiate into any cell type of the body. Their use, however, raises ethical concerns because embryos are being destroyed in the process. In contrast, neural crest stem cells from adults have several advantages: similar to embryonic stem cells, they have the innate ability to differentiate into many diverse cell types; they are easily accessible in the skin of adults; and the patient's own neural crest stem cells could be used for cell therapy. The latter avoids both rejection of the implant and graft-versus-host disease. Studies in the mouse showed that neural crest stem cells from adult hair follicles are able to differentiate into neurons, nerve supporting cells, cartilage/bone cells, smooth muscle cells, and pigment cells. Preliminary data indicate that equivalent stem cells reside in human hair follicles.

Keyword: Stem Cells
Link ID: 6564 - Posted: 06.24.2010

By JANE GROSS RADELL, N.J. - When Mark Plage, 15, forgets to padlock the door of his bedroom, his 13-year-old autistic brother, Derek, barges in and leaves the place a shambles. When Mark tries to toss a football with Derek, the boy turns his back and walks away. Mark's mother, by her own admission, used to scream at him for the smallest thing, unable to contain her frustration with Derek. Mark often wished she would come to his ice hockey games with his father. But Debi Plage had to stay home with her disabled son. Mark recounts these experiences without reproach and with insight well beyond his years. When Derek "messes something up," Mark said, "I just fix it." As for his brother's inability to play, he said, "I know that it's not that he won't do it, but that he can't." His mother's rages were "harder to deal with," Mark said, but "after a while I realized she wasn't really yelling at me." He can even brush aside her occasional threats to leave home and never come back. "I knew in the back of my mind she'd never do it," Mark said. "She was just saying stuff because she was really upset." Copyright 2004 The New York Times Company

Keyword: Autism
Link ID: 6563 - Posted: 12.10.2004

DURHAM, N.C. – A newly discovered genetic defect might represent an important risk factor for major depression, a condition which effects 20 million people in the U.S., according to Duke University Medical Center researchers. The mutation in the gene -- whose protein product plays a primary role in synthesizing the brain chemical serotonin -- could lead to the first diagnostic test for genetic predisposition to depression, the team said. "Abnormalities in brain levels of serotonin have been widely suspected as a key contributor to major depression and other neuropsychiatric disorders," said James B. Duke professor Marc Caron, Ph.D., a researcher in the department of cell biology, the Duke Institute for Genome Sciences and Policy and senior author of the study. "Our findings provide a novel molecular mechanism underlying dysfunction in serotonin neurotransmission in some patients with depression." The genetic defect is the first genetic variant of functional consequence in the production of serotonin identified in any psychiatric disorder, the researchers said. Patients with depression who carry the abnormal gene also show resistance to treatment with selective serotonin reuptake inhibitors (SSRIs), a class of drugs that includes paroxetine (PaxilTM), sertraline (ZoloftTM), and fluoxetine (ProzacTM), the team found. In addition to its diagnostic use, the genetic marker might therefore also aid in identifying, in advance, those patients who will likely fail to respond well to SSRI therapy.

Keyword: Depression; Genes & Behavior
Link ID: 6562 - Posted: 06.24.2010

ANN ARBOR, Mich.---Men are more likely to want to marry women who are their assistants at work rather than their colleagues or bosses, a University of Michigan study finds. The study, published in the current issue of Evolution and Human Behavior, highlights the importance of relational dominance in mate selection and discusses the evolutionary utility of male concerns about mating with dominant females. "These findings provide empirical support for the widespread belief that powerful women are at a disadvantage in the marriage market because men may prefer to marry less accomplished women," said Stephanie Brown, lead author of the study and a social psychologist at the U-M Institute for Social Research (ISR). For the study, supported in part by a grant from the National Institute of Mental Health, Brown and co-author Brian Lewis from UCLA tested 120 male and 208 female undergraduates by asking them to rate their attraction and desire to affiliate with a man and a woman they were said to know from work.

Keyword: Sexual Behavior; Evolution
Link ID: 6561 - Posted: 12.10.2004

Michael Hopkin Capuchins in the dry forests of northeastern Brazil have an unusual approach to food: they have been caught using tools to dig up tubers, a feat previously only seen in humans. "They're using their minds, not just brute force," claims Phyllis Lee of the University of Cambridge, UK, who reports the discovery with her colleague Antonio Moura in this week's Science1. Although many primates, particularly chimpanzees and orang utans, are thought to be good at reasoning things out for themselves, digging for food has never been seen before, in the wild or in captivity. Several species are known to use 'tools', such as the birds of prey that dash their hard-shelled prey on to rocks to crack them open. But the latest case of tool use differs from many of these examples because it may be based on an understanding of cause and effect. ©2004 Nature Publishing Group

Keyword: Evolution
Link ID: 6560 - Posted: 06.24.2010

Roxanne Khamsi Studies showing that magnetic stimulation of the brain induces spiritual experiences are being queried by researchers who cannot reproduce key results. If the traditional theory is wrong, scientists will be left struggling to explain how such thoughts and sensations are generated. In the past, scientists have claimed that religious or out-of-body experiences result from excessive bursts of electrical activity in the brain. In the 1980s, Michael Persinger, a neuroscientist at the Laurentian University in Ontario, Canada, began exploring this idea through a series of experiments. Participants wore helmets that targeted their temporal lobes with weak magnetic fields, of roughly the same strength as those generated by a computer monitor. Persinger found that this caused 80% of the people he tested to feel an unexplained presence in the room. Persinger suggested that magnetism causes bursts of electrical activity in the temporal lobes of the brain, and he linked this to the spiritual experiences. A group of Swedish researchers has now repeated the work, but they say their study involves one crucial difference. They ensured that neither the participants nor the experimenters interacting with them had any idea who was being exposed to the magnetic fields, a 'double-blind' protocol. ©2004 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 6559 - Posted: 06.24.2010

More research has been published linking smoking to health risks - with a study suggesting the habit affects IQ Researchers from the Universities of Aberdeen and Edinburgh looked at how the cognitive abilities of smokers and non-smokers changed over time. They found smokers performed significantly worse in five separate tests. The research, part of the Scottish Mental Health Survey, is published in New Scientist magazine. Around 465 people were tested on their mental abilities in 1947 when they were aged 11. They were then tested a second time between 2002 and 2002, when they reached the age of 64. On this occasion they underwent tests to evaluate their non-verbal reasoning, memory and learning, how quickly they processed information, decisions about how to act in particular circumstances and construction tasks. Current or former smokers were found to perform less well in the tests even after factors such as childhood IQ, education, occupation and alcohol consumption were taken into account. The effect appeared to be stronger in current smokers according to the study, which was also published in the journal Addictive Behaviors. The researchers suggest a "small but significant" negative effect of 4% linked to the combined effects of smoking and impaired lung function - itself linked to smoking. It has been suggested in previous studies that there could be a link between impaired lung function and a negative effect on the thinking processes, but it is not clear what the mechanism for that might be. (C)BBC

Keyword: Drug Abuse; Intelligence
Link ID: 6558 - Posted: 12.09.2004

University of Utah scientists taught baby sparrows to sing a complete song even though the birds were exposed only to overlapping segments of the tune rather than the full melody. The study provides clues about how musical memories are stored in the brain and how those memories help birds learn to sing. The results also may have implications for how people learn language, says Gary J. Rose, a University of Utah professor of biology and principal author of the study published in the Dec. 9 issue of the journal Nature. "There are strong parallels between song learning in birds and speech learning in humans," he says. "Like humans, songbirds learn particular regional dialects, so they represent excellent opportunities to study the physiological basis of language. If we can understand something about how song is represented in their brains, then maybe we can better understand how speech learning occurs in humans and, when it goes awry, how we might go about fixing it." Study co-author Stephanie Plamondon, a doctoral student in neuroscience, added: "We were able to give the birds just pieces of the song, and they were able to assemble a complete song from those pieces. … A full song or a complete sentence isn't required to learn the song, only an association between phrases [segments] of the song."

Keyword: Language; Sexual Behavior
Link ID: 6557 - Posted: 12.09.2004

Why is it that we can look at something, know what it is and still call a rose by a different name? Breaking from conventional wisdom, new research suggests that it isn't a rushed pace or distraction that makes us slip up, but rather a hiccup in how we plan what we're going to say that messes things up. People usually look at things before they name them. For instance, before they say "a hammer," they look at the hammer for a second. But what about when they see a hammer and unintentionally call it "an axe"? Zenzi M. Griffin, Georgia Institute of Technology, assumed people made the mistake when they didn't look at the hammer long enough, which could reflect rushed word preparation, forgetting to check the name they had mentally prepared against the object, or paying too much attention to other objects. But Griffin discovered that people who say "axe" when they mean "hammer" look at the hammer just as long as they do when they say "hammer." However, they look at the hammer longer after they call it "an axe," apparently as they prepare to correct their mistake. In her study, "The Eyes Are Right When the Mouth Is Wrong," Griffin concluded that, as with a gesture, a person's gaze may accurately reflect what he intends, even if his words do not. The study will be published in the December issue of Psychological Science, a journal of the American Psychological Society.

Keyword: Language
Link ID: 6556 - Posted: 12.09.2004

By Jennifer Viegas, Discovery News — A forthcoming book claims that the sixteenth president of the United States, Abraham Lincoln, was a homosexual, based on evidence ranging from a post-assassination interview with Lincoln's stepmother to a poem about gay marriage written by the Civil War leader. The book, entitled "The Intimate World of Abraham Lincoln," will be published on Jan. 11 by The Free Press, a Simon & Schuster company. It was authored by C.A. Tripp, associate professor of psychiatry at the State University of New York, and a researcher who worked closely with Alfred Kinsey on studies concerning human sexuality. Tripp died at the age of 83, just two weeks after finishing the book, which he worked on over the last 14 years of his life. To argue his case that Lincoln (1809-1865) was gay, Tripp gathered biographical texts contemporary to Lincoln's time, private correspondence, and other books and documents culled from his database of more than 600 Lincoln-related texts, which now are housed at the Lincoln Institute in Springfield, Ill. Copyright © 2004 Discovery Communications Inc.

Keyword: Sexual Behavior
Link ID: 6555 - Posted: 06.24.2010

By DAN NEPHIN, Associated Press Writer PITTSBURGH - A researcher studying sleep for NASA (news - web sites) has found the body has more difficulty adjusting to different sleep times than previously thought. The space agency has been advising astronauts to begin going to bed two hours later than normal over a period of time to prepare for their desired sleep schedule, according to Timothy Monk, a University of Pittsburgh Medical Center psychiatry professor who is leading a study to find the best way to shift sleep cycles. That may not be the best approach, however. "There's no doubt that changing your biological clock is difficult," Monks said Tuesday. "What we're trying to do here is basically address the question of how you cope with something that is difficult." Copyright © 2004 The Associated Press. Copyright © 2004 Yahoo! Inc.

Keyword: Biological Rhythms
Link ID: 6554 - Posted: 06.24.2010

By Shankar Vedantam, Washington Post Staff Writer British health officials advised doctors yesterday not to prescribe antidepressants for about 70 percent of the patients who show up complaining of depression without first trying exercise, self-help, talk therapy or just waiting a couple of weeks to see if they got better. In issuing new treatment guidelines for doctors, the British regulators and a standards-setting panel said patients with mild depression who are able to go to work and function normally, even if they complain of symptoms such as a lack of interest in things, low energy, dark mood, difficulty sleeping or difficulty concentrating, should avoid widely used antidepressants at first because of the possibility of side effects and withdrawal symptoms. The regulatory panel is the same one that last year triggered a major reevaluation of the use of antidepressants in children after it concluded that the drugs were associated with an increased risk of suicidal tendencies in children. The recommendations that the drugs not be used as first-line treatment for mild depression are the latest evidence that some experts are reexamining the widespread enthusiasm for the medications. © 2004 The Washington Post Company

Keyword: Depression
Link ID: 6553 - Posted: 06.24.2010

What can cellular neuroscientists learn about the human brain from studying a marine snail? Much more than one might suspect. "On a cell biological level, the mechanisms of learning and memory are identical, as far as we can tell," said David Glanzman, a UCLA professor of physiological science and neurobiology, whose research has strengthened the view that the human brain and that of a snail named Aplysia are surprisingly similar. "Human brains have many more neurons than the Aplysia's, but it doesn't look like there is any difference on a molecular or synaptic level. "When this animal learns," Glanzman said, "many changes take place in its nervous system. I want to understand what causes these changes for certain forms of learning; I want to understand everything there is to understand. This knowledge will inform us about the kinds of changes that take place in our brains when we learn." Glanzman's quest for this knowledge will be helped by his selection in November as one of eight scientists awarded the prestigious Senator Jacob Javits Award in the Neurosciences, which provides up to seven years of research funding from the National Institute of Neurological Disorders and Stroke (NINDS). The Jacob Javits Award is presented to investigators who have "demonstrated exceptional scientific excellence and productivity in research areas supported by the NINDS and who are expected to conduct cutting-edge research over the next seven years."

Keyword: Learning & Memory
Link ID: 6552 - Posted: 12.08.2004

By Jennifer Viegas, Discovery News — An electrode-covered hat can translate brain waves into computer commands, a non-invasive thought decoder that could someday let the disabled communicate by using their brains alone, according to a new study. The hat may someday also be used to operate word processing programs or control movement of a robotic prosthesis. The study is published in the current Proceedings of the National Academy of Sciences. Jonathan Wolpaw, lead author of the study and chief of the Laboratory of Nervous System Disorders at the Wadsworth Center within the New York State Department of Health and the State University of New York, described the mind-reading hat to Discovery News. "It looks sort of like a light-weight elastic version of an old-fashioned rubber swimming cap, with small metal disks that are connected by a ribbon cable to EEG amplifiers and the computer," Wolpaw said. Copyright © 2004 Discovery Communications Inc.

Keyword: Robotics
Link ID: 6551 - Posted: 06.24.2010

COLLEGE STATION, Dec. 7, 2004 - Teen-agers suffering from bulimia may in fact be fighting a two-front war, coping with the effects of a devastating eating disorder while struggling with a chronic form of depression, reveals research by Texas A&M University psychologist Marisol Perez, who says the finding has critical implications for the way the disorder is treated. Often masked by the bulimia itself, dysthymia - a lower-level, chronic form of depression - is often present in bulimics and may even predispose them to the eating disorder, shows the research by Perez and her colleagues Thomas E. Joiner Jr. of Florida State University and Peter M. Lewinsohn of the Oregon Research Institute. Dysthymia, Perez explains, is different from the more familiar major depression in terms of its duration, severity and persistence of mood disturbance, all factors that can impact the course and treatment of eating disorders. "As pernicious as major depression can be, it tends to remit, even if untreated," she notes. "By contrast, dysthymia is unrelenting, often lasting decades, with the average episode length lasting more than 10 years."

Keyword: Anorexia & Bulimia; Depression
Link ID: 6550 - Posted: 12.08.2004

Michael Hopkin Left-handed people thrive best in the most murderous societies, according to a study of tribes across the world. The discovery may help to answer the riddle of why a minority of left-handers persist in human populations. Being a southpaw is an advantage in a host of confrontational situations. Lefties are far more common at the top of sports such as boxing and fencing than in normal society. The benefit comes from the element of surprise: most opponents will be less used to facing a left-handed adversary. But left-handedness comes at a cost. Developmental experts think that stress during development or birth may divert the nervous system from its default, right-handed path. And developmental stress is also linked to reduced lifespan, low birthweight and increased incidence of immune and nervous disorders, meaning that natural selection might be expected to weed out lefties altogether. ©2004 Nature Publishing Group

Keyword: Aggression; Laterality
Link ID: 6549 - Posted: 06.24.2010

David Cyranoski A lens resembling an octopus eye has been created by US researchers. The sphere consists of hundreds of thousands of layers of plastic and could revolutionize cameras, telescopes and spectacles. Traditional glass lenses use a curved surface to focus incoming light towards a central point. The stronger the lens, the more curved its surface must be and therefore the thicker and heavier it is. In nature, eyes avoid this problem by using materials whose density varies in a certain way. Light is bent, or refracted, when it travels between two substances that have different densities (or refractive indices), such as air and water. The greater the difference between the two materials, the more the light is refracted. So a flat object that has a greater refractive index towards its edges can focus light like a curved lens. Many biological lenses consist of up to hundreds of thousands of nanolayers, each of which has a slightly different refractive index. The layers form a smooth density gradient that helps to focus light. ©2004 Nature Publishing Group

Keyword: Vision
Link ID: 6548 - Posted: 06.24.2010

Scientists have developed a treatment which may be effective against the most common and deadly form of brain cancer. Glioblastoma multiforme (GBM) usually grows so quickly that it kills within a year of diagnosis, and neither surgery, drugs or radiotherapy can stop it. But a team from Cedars-Sinai Medical Center in Los Angeles has boosted survival of lab rats with the tumour by injecting them with a protein. Details are published in the journal Molecular Therapy. The researchers used a genetically modified virus to deliver a small protein called hsFlt3L into the brains of lab rats who had developed GBM. They found that the protein increased the number of immune cells in the brain, and significantly slowed tumour growth. Seven out of 10 rats given a high dose of the protein survived for over a year. There were no signs of adverse side effects. In contrast, rats treated with a dummy injection died from their tumours within one week. Among rats treated with hsFlt3L, 33% were completely tumour free at three months, while all those who survived for six months or longer had no tumours at all. (C) BBC

Keyword: Glia
Link ID: 6547 - Posted: 12.07.2004

Children born in May have an increased risk of going on to develop multiple sclerosis, research has suggested. The analysis of MS rates among over 42,000 people born in the northern hemisphere showed a significantly lower risk for those born in November. The effect was most evident in Scotland, where the prevalence of MS was the highest. The study, published online by the British Medical Journal, was carried out by Oxford University researchers. The team suggest that complex interactions between genes and the environment before or shortly after birth may help to explain the links they found. They analysed data on the birth month, medical and family histories of 17,874 Canadian patients and 11,502 British patients with MS. They were compared with a matched group of people from the general population and unaffected brothers and sisters of those with MS In Canada, significantly fewer people with MS were born in November compared with the general population or sibling groups. And in Britain, fewer people with MS had been born in November and significantly more had been born in May. The number born in December was also significantly lower. The researchers also looked at data from Denmark and Sweden, which again showed a May peak and a November fall. (C)BBC

Keyword: Multiple Sclerosis; Biological Rhythms
Link ID: 6546 - Posted: 12.07.2004