Rating Attractiveness: Consensus Among Men, Not Women, Study Finds

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ScienceDaily (June 27, 2009) — Hot or not? Men agree on the answer. Women don't.

There is much more consensus among men about whom they find attractive than there is among women, according to a new study by Wake Forest University psychologist Dustin Wood.
The study, co-authored by Claudia Brumbaugh of Queens College, appears in the June issue of the Journal of Personality and Social Psychology.
"Men agree a lot more about who they find attractive and unattractive than women agree about who they find attractive and unattractive," says Wood, assistant professor of psychology. "This study shows we can quantify the extent to which men agree about which women are attractive and vice versa."
More than 4,000 participants in the study rated photographs of men and women (ages 18-25) for attractiveness on a 10-point scale ranging from "not at all" to "very." In exchange for their participation, raters were told what characteristics they found attractive compared with the average person. The raters ranged in age from 18 to more than 70.
Before the participants judged the photographs for attractiveness, the members of the research team rated the images for how seductive, confident, thin, sensitive, stylish, curvaceous (women), muscular (men), traditional, masculine/feminine, classy, well-groomed, or upbeat the people looked.
Breaking out these factors helped the researchers figure out what common characteristics appealed most to women and men.
Men's judgments of women's attractiveness were based primarily around physical features and they rated highly those who looked thin and seductive. Most of the men in the study also rated photographs of women who looked confident as more attractive.
As a group, the women rating men showed some preference for thin, muscular subjects, but disagreed on how attractive many men in the study were. Some women gave high attractiveness ratings to the men other women said were not attractive at all.
"As far as we know, this is the first study to investigate whether there are differences in the level of consensus male and female raters have in their attractiveness judgments," Wood says. "These differences have implications for the different experiences and strategies that could be expected for men and women in the dating marketplace."
For example, women may encounter less competition from other women for the men they find attractive, he says. Men may need to invest more time and energy in attracting and then guarding their mates from other potential suitors, given that the mates they judge attractive are likely to be found attractive by many other men.
Wood says the study results have implications for eating disorders and how expectations regarding attractiveness affect behavior.
"The study helps explain why women experience stronger norms than men to obtain or maintain certain physical characteristics," he says. "Women who are trying to impress men are likely to be found much more attractive if they meet certain physical standards, and much less if they don't. Although men are rated as more attractive by women when they meet these physical appearance standards too, their overall judged attractiveness isn't as tightly linked to their physical features."
The age of the participants also played a role in attractiveness ratings. Older participants were more likely to find people attractive if they were smiling.
Adapted from materials provided by Wake Forest University.

Some Video Games Can Make Children Kinder And More Likely To Help

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ScienceDaily (June 18, 2009) — Some video games can make children kinder and more likely to help—not hurt—other people.

That's the conclusion of new research published in the June 2009 issue of Personality and Social Psychology Bulletin.
The article presents the findings of three separate studies, conducted in different countries with different age groups, and using different scientific approaches. All the studies find that playing games with prosocial content causes players to be more helpful to others after the game is over.
The report is co-authored by a consortium of researchers from the United States, Japan, Singapore and Malaysia.
"Dozens of studies have documented a relationship between violent video games and aggressive behaviors," said lead author Douglas Gentile, an Iowa State University psychologist. "But this is one of the first that has documented the positive effects of playing prosocial games."
Prosocial video games involve characters who help and support each other in nonviolent ways.
"These studies show the same kind of impact on three different age groups from three very different cultures," said Brad Bushman, a University of Michigan co-author of the report. "In addition, the studies use different analytic approaches—correlational, longitudinal and experimental. The resulting triangulation of evidence provides the strongest possible proof that the findings are both valid and generalizable."
"These studies document that children and adolescents learn from practicing behaviors in games," said Rowell Huesmann, a U-M co-author of the report.
One study examined the link between video game habits and prosocial behavior among 727 secondary students in Singapore, with a mean age of 13. Students listed their favorite games and rated how often game characters helped, hurt or killed other characters. They also answered questions about how likely they were to spend time and money helping people in need, to cooperate with others and share their belongings, and to react aggressively in various situations.
As in numerous other studies, the researchers found a strong correlation between playing violent video games and hurting others. But the study also found a strong correlation between playing prosocial games and helping others.
The second study analyzed the long-term connection between video game habits and prosocial behavior in nearly 2,000 Japanese children ages 10 to 16. Participants completed a survey about their exposure to prosocial video games, and rated how often they had helped other people in the last month. Three to four months later, they were surveyed again, and researchers found a significant connection between exposure to prosocial games and helpful behavior months later.
"This suggests there is an upward spiral of prosocial gaming and helpful behavior, in contrast to the downward spiral that occurs with violent video gaming and aggressive behavior," said Bushman, a professor of communications and psychology and a research professor at the U-M Institute for Social Research (ISR).
For the third study, the researchers carried out an experiment with 161 U.S. college students, with a mean age of 19. After playing either a prosocial, violent, or neutral game, participants were asked to assign puzzles to a randomly selected partner. They could choose from puzzles that were easy, medium or hard to complete. Their partner could win $10 if they solved all the puzzles. Those who played a prosocial game were considerably more helpful than others, assigning more easy puzzles to their partners. And those who had played violent games were significantly more likely to assign the hardest puzzles.
"Taken together, these findings make it clear that playing video games is not in itself good or bad for children," Bushman said."The type of content in the game has a bigger impact than the overall amount of time spent playing."
Adapted from materials provided by University of Michigan.

Be Your Best Friend If You'll Be Mine: Alliance Hypothesis For Human Friendship

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ScienceDaily (June 5, 2009) — University of Pennsylvania psychologists studying the cognitive mechanisms behind human friendship have determined that how you rank your best friends is closely related to how you think your friends rank you. The results are consistent with a new theory called the Alliance Hypothesis for Human Friendship, distinct from traditional explanations for human friendship that focused on wealth, popularity or similarity.

The study, performed by Penn cognitive psychologists Peter DeScioli and Robert Kurzban, has demonstrated that human friendship is caused, in part, by cognitive mechanisms aimed at creating a ready-made support group for potential conflicts. People call on friends for help in a variety of disputes, ranging from trivial arguments to violent fights. This study suggests that people have specialized decision processes that prioritize those individuals who tend to be most helpful in conflicts, those with fewer stronger commitments to others.
Researchers performed question-and-answer studies in which participants ranked their closest friends in a number of ways, including, for example, the benefits they receive from the friendship, the number of secrets shared and how long the friendship has been ongoing. Each time, whether participants were an online community, random passersby on a metropolitan street or undergraduate students in a laboratory, friendship rankings were most strongly correlated with individuals' own perceived rank among their partners' other friends.
"Historically, the main theory has been that humans build friendships in order to trade in goods and services," DeScioli, lead author, said. "The problem we focused on was that friendship involves more than exchange. People want friends who care about them and do not give just to get something back in return. We thought that theories about alliances might help explain why friends are primarily concerned with each others' needs rather than the benefits they can get in return for helping."
Traditional evolutionary approaches to explain human friendship apply the Theory of Reciprocal Altruism: Friends function as exchange partners; however, a wealth of empirical evidence from social psychology is inconsistent with the theory. For example, in prior studies it was shown that people do not keep regular tabs on the benefits given and received in close relationships. Also, people seem to help friends even when they are unlikely to be capable of repayment. For cognitive psychologists, it is unclear what humans and their complex brains are up to in creating these relationships.
The new Penn theory has origins in models of alliance building between nations, which prepare for conflict in advance but may not expect anything in return immediately.
"Friendships are about alliances," Kurzban, an associate professor, said. "We live in a world where conflict can arise and allies must be in position beforehand. This new hypothesis takes into account how we value those alliances. In a way, one of the main predictors of friendship is the value of the alliance. The value of an ally, or friend, drops with every additional alliance they must make, so the best alliance is one in which your ally ranks you above everyone else as well."
In short, the hypothesis is much more optimistic about the reasons for friendship than existing theories which point toward popularity, wealth and proximity as reasons for friendship.
"In this hypothesis," Kurzban said, "it's not what you can do for me, it's how much you like me. In this manner even the weakest nations, for example, or the least popular kid at the party with nary an alliance in the room is set up to be paired with someone looking for a friend."
More darkly, the new model also serves as an explanation for some petty human behaviors not explained by traditional friendship theories. For example, the Alliance Hypothesis explains why people are extremely concerned with comparisons to others in their social circle. It also explains how jealousies and aggression can erupt among groups of friends as alliances are shifted and maintained.
If the Alliance Hypothesis for Human Friendship is correct, then theories about alliances from game theory and international relations might help us better understand friendship. These theories suggest that people in conflict would benefit strategically from ranking their friends, hiding their friend-rankings and ranking friends according to their own position in partners' rankings. To employ these tactics in their friendships, people need to gather and store information about their friends' other friendships. That is, they have to readily understand the social world not only from their own perspective but also from the perspectives of their friends.
Although friendship is a core element of human social life, its evolved functions have been difficult to understand. Human friendship occurs among individuals who are neither relatives nor mates, so the function of this cooperative behavior is not as clear as when reproduction or genetic relatives are involved. Similar relationships have been observed in non-human species -- hyenas use partners to gain access to carcasses and male dolphins employ "wingmen" to attain females for mating — and considerable progress has been made in understanding these non-human relationships. But the functions of human friendship have been more elusive.
The study, appearing in the current issue of the online journal Public Library of Science One, was conducted by DeScioli and Kurzban of the Department of Psychology in the School of Arts and Sciences at Penn.
It was supported by a fellowship from the International Foundation for Research in Experimental Economics.
Adapted from materials provided by University of Pennsylvania, via EurekAlert!, a service of AAAS.

Basket Weaving May Have Taught Humans To Count

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ScienceDaily (June 3, 2009) — Did animals teach us one of the oldest forms of human technology? Did this technology contribute to our ability to count? These are just two of the themes due to be explored at a conference on basketry at the University of East Anglia.

The event, which takes place today and tomorrow (June 5-6), is part of Beyond the Basket, a major new research project led by the university exploring the development and use of basketry in human culture over 10,000 years.
Basketry has been practised for millennia and ranges from mats for sitting on, containers and traps for hunting, to fencing and barriers for animals or land, partitions and walls - all of which have been central to culture.
Beyond the Basket is a two-and-a-half year project funded by the Arts and Humanities Research Council as part of its Beyond Text programme. The research will explore the role of basketry in human culture and focus on various parts of the world, both in the past and present, from Europe to Amazonia, central Africa and Papua New Guinea.
The aim is to identify the mechanical traditions of making and the ways in which basketry is implicated in wider patterns of understanding, for example the order of society or the design of the universe. It will also show the impact of woven forms on other media, such as pottery, painting, and stone sculpture and architecture, and look at the future of basketry and the solutions it could offer to current issues, whether technical or social.
Project leader Sandy Heslop, of the School of World Art and Museology at UEA, said: “Basketry is a worldwide technology and is the interaction between human ingenuity and the environment. It tends to make use of, and therefore has to be adapted to, local conditions in terms of resources and environment.
“Without basketry there would be no civilisations. You can’t bring thousands of people together unless you can supply them, you can’t bring in supplies to feed populations without containers. In the early days of civilisations these containers were basketry.
“We may think of baskets as humble, but other people and cultures don’t. They have been used for storage, for important religious and ceremonial processes, even for bodies in the form of coffins.”
It is about 10,000 years ago that evidence for basketry starts to appear in North America, Asia, Europe and the Middle East. Today its uses and influences are still seen, from the bamboo scaffolding often used in Asia, to contemporary architecture, for example the ‘Boiler Suit’ - the name given to the ‘woven’ steel tiles encasing the boiler room at Guy’s Hospital in London.
Mr Heslop said: “Beyond its practical uses, basketry has arguably been even more influential on our lives, since it relies on the relationship of number, pattern and structure. It therefore provides a model for disciplines such as mathematics and engineering and for the organisation of social and political life.
“Given the range of uses of basketry the associations of the technology are very varied. Some are aggressive, others protective, some help create social hierarchies others are recreational.”
The conference, Beyond the Basket: Construction, Order and Understanding, will look at various themes including: design and production, environmental issues, commercial and historical perspectives, weaving in architecture, and the mathematics of basketry, as well as more anthropological and archaeological topics. Among the speakers will be experts from North and South America, as well as the UK.
Beyond the Basket will culminate in an exhibition and accompanying book in 2011. The exhibition will include ancient material recovered by excavation as well as more recent examples of basketry from around the world and will enable people to experience basketry directly.
For further information about Beyond the Basket and to view images visit http://projects.beyondtext.ac.uk/beyondthebasket
Adapted from materials provided by University of East Anglia, via AlphaGalileo.

High Population Density Triggers Cultural Explosions

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ScienceDaily (June 5, 2009) — Increasing population density, rather than boosts in human brain power, appears to have catalysed the emergence of modern human behaviour, according to a new study by UCL (University College London) scientists published in the journal Science.

High population density leads to greater exchange of ideas and skills and prevents the loss of new innovations. It is this skill maintenance, combined with a greater probability of useful innovations, that led to modern human behaviour appearing at different times in different parts of the world.
In the study, the UCL team found that complex skills learnt across generations can only be maintained when there is a critical level of interaction between people. Using computer simulations of social learning, they showed that high and low-skilled groups could coexist over long periods of time and that the degree of skill they maintained depended on local population density or the degree of migration between them. Using genetic estimates of population size in the past, the team went on to show that density was similar in sub-Saharan Africa, Europe and the Middle-East when modern behaviour first appeared in each of these regions. The paper also points to evidence that population density would have dropped for climatic reasons at the time when modern human behaviour temporarily disappeared in sub-Saharan Africa.
Adam Powell, AHRC Centre for the Evolution of Cultural Diversity, says: "Our paper proposes a new model for why modern human behaviour started at different times in different regions of the world, why it disappeared in some places before coming back, and why in all cases it occurred more than 100,000 years after modern humans first appeared.
"By modern human behaviour, we mean a radical jump in technological and cultural complexity, which makes our species unique. This includes symbolic behavior, such as abstract and realistic art, and body decoration using threaded shell beads, ochre or tattoo kits; musical instruments; bone, antler and ivory artefacts; stone blades; and more sophisticated hunting and trapping technology, like bows, boomerangs and nets.
Professor Stephen Shennan, UCL Institute of Archaeology, says: "Modern humans have been around for at least 160,000 to 200,000 years but there is no archaeological evidence of any technology beyond basic stone tools until around 90,000 years ago. In Europe and western Asia this advanced technology and behaviour explodes around 45,000 years ago when humans arrive there, but doesn't appear in eastern and southern Asia and Australia until much later, despite a human presence. In sub-Saharan Africa the situation is more complex. Many of the features of modern human behaviour – including the first abstract art – are found some 90,000 years ago but then seem to disappear around 65,000 years ago, before re-emerging some 40,000 years ago.
"Scientists have offered many suggestions as to why these cultural explosions occurred where and when they did, including new mutations leading to better brains, advances in language, and expansions into new environments that required new technologies to survive. The problem is that none of these explanations can fully account for the appearance of modern human behaviour at different times in different places, or its temporary disappearance in sub-Saharan Africa."
Dr Mark Thomas, UCL Genetics, Evolution and Environment, says: "When we think of how we came to be the sophisticated creatures we are, we often imagine some sudden critical change, a bit like when the black monolith appears in the film 2001: A Space Odyssey. In reality, there is no evidence of a big change in our biological makeup when we started behaving in an intelligent way. Our model can explain this even if our mental capacities are the same today as they were when we first originated as a species some 200,000 years ago.
"Ironically, our finding that successful innovation depends less on how smart you are than how connected you are seems as relevant today as it was 90,000 years ago."
Journal reference:
Adam Powell, Stephen Shennan, and Mark G. Thomas. Late Pleistocene Demography and the Appearance of Modern Human Behavior. Science, 2009; 324 (5932): 1298 DOI: 10.1126/science.1170165
Adapted from materials provided by University College London, via EurekAlert!, a service of AAAS.

Why Emotionally Charged Events Are So Memorable

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http://www.sciencedaily.com/releases/2007/10/071004121045.htm

Science Daily — Both extensive psychological research and personal experiences confirm that events that happen during heightened states of emotion such as fear, anger and joy are far more memorable than less dramatic occurrences.

"This phenomenon is something everyone can identify with," said Roberto Malinow of the Cold Spring Harbor Laboratory in New York. "You can probably remember where you were when you heard about 9/11, but you probably don't know where you were on 9/10. We've identified one mechanism that may underlie this effect."
The parts of the brain where memories are stored need to distinguish between significant experiences and those that carry less importance, giving priority to the transformation of the former into long-term memory, the researchers explained.
One factor that scientists believe to be critical in that process is the emotional load of an event. Indeed, studies have shown that heightened states of emotion can facilitate learning and memory. In some situations, this process can even become pathological, Malinow said, as occurs in posttraumatic stress disorder (PTSD), a condition characterized by persistent vivid memories of traumatic events.
In a report in Cell, Johns Hopkins researchers and their collaborators at Cold Spring Harbor and New York University have identified the likely biological basis for this: a hormone released during emotional arousal "primes" nerve cells to remember events by increasing their chemical sensitivity at sites where nerves rewire to form new memory circuits.
Describing the brain as a big circuit board in which each new experience creates a new circuit, Hopkins neuroscience professor Richard Huganir, Ph.D. says that he and his team found that during emotional peaks, the hormone norepinephrine dramatically sensitizes synapses -- the site where nerve cells make an electro-chemical connection -- to enhance the sculpting of a memory into the big board.
Norepinephrine, more widely known as a "fight or flight" hormone, energizes the process by adding phosphate molecules to a nerve cell receptor called GluR1. The phosphates help guide the receptors to insert themselves adjacent to a synapse. "Now when the brain needs to form a memory, the nerves have plenty of available receptors to quickly adjust the strength of the connection and lock that memory into place," Huganir says.
Huganir and his team suspected that GluR1might be a target of norepinephrine since disruptions in this receptor cause spatial memory defects in mice. They tested the idea by either injecting healthy mice with adrenaline or exposing them to fox urine, both of which increase norepinephrine levels in brain. Analyzing brain slices of the mice, the researchers saw increased phosphates on the GluR1 receptors and an increased ability of these receptors to be recruited to synapses.
When the researchers put mice in a cage, gave a mild shock, took them out of that cage and put them back in it the next day, mice who had received adrenaline or fox urine tended to "freeze" in fear -- an indicator they associated the cage as the site of a shock -- more frequently, suggestive of enhanced memory.
However, in a similar experiment with mice genetically engineered to have a defective GluR1 receptor that phosphates cannot attach to, adrenaline injections had no effect on mouse memory, further evidence of the "priming" effect of the receptor in response to norepinephrine.
The researchers plan on continuing their work by going in the opposite direction and engineering another mouse strain that has a permanently phosphorylated or "primed" receptor. "We're curious to see how these mice will behave," Huganir says. "We suspect that they'll be pretty smart, but at the same time constantly anxious."
Reference: Hu et al.: "Emotion Enhances Learning via Norepinephrine Regulation of AMPA-Receptor Trafficking." Publishing in Cell 131, 160--173, October 5, 2007. DOI 10.1016/j.cell.2007.09.017
Authors on the paper are Hailan Hu, Eleonore Real, and Roberto Malinow of Cold Spring Harbor Laboratory; Joe LeDoux of New York University; and Kogo Takamiya, Myoung-Goo Kang, and Huganir of Johns Hopkins.
The research was funded by the National Institutes of Health, Damon Runyon Postdoctoral Fellowship, NARSAD, and the Ale Davis and Maxine Harrison Foundation
Note: This story has been adapted from material provided by Johns Hopkins Medical Institutions.

Fausto Intilla

www.oloscience.com

Brain Images Make Cognitive Research More Believable

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http://www.sciencedaily.com/releases/2007/10/071002151837.htm

Science Daily — People are more likely to believe findings from a neuroscience study when the report is paired with a colored image of a brain as opposed to other representational images of data such as bar graphs, according to a new Colorado State University study.

Persuasive influence on public perception:

Scientists and journalists have recently suggested that brain images have a persuasive influence on the public perception of research on cognition. This idea was tested directly in a series of experiments reported by David McCabe, an assistant professor in the Department of Psychology at Colorado State, and his colleague Alan Castel, an assistant professor at University of California-Los Angeles. The forthcoming paper, to be published in the journal Cognition, was recently published online.
"We found the use of brain images to represent the level of brain activity associated with cognitive processes clearly influenced ratings of scientific merit," McCabe said. "This sort of visual evidence of physical systems at work is typical in areas of science like chemistry and physics, but has not traditionally been associated with research on cognition.
"We think this is the reason people find brain images compelling. The images provide a physical basis for thinking."

Brain images compelling:

In a series of three experiments, undergraduate students were either asked to read brief articles that made fictitious and unsubstantiated claims such as "watching television increases math skills," or they read a real article describing research showing that brain imaging can be used as a lie detector.
When the research participants were asked to rate their agreement with the conclusions reached in the article, ratings were higher when a brain image had accompanied the article, compared to when it did not include a brain image or included a bar graph representing the data. This effect occurred regardless of whether the article described a fictitious, implausible finding or realistic research.
Conclusions often oversimplified and misrepresented
"Cognitive neuroscience studies which appear in mainstream media are often oversimplified and conclusions can be misrepresented," McCabe said. "We hope that our findings get people thinking more before making sensational claims based on brain imaging data, such as when they claim there is a 'God spot' in the brain."
Article: "Seeing is believing: The effect of brain images on judgments and scientific reasoning."
Note: This story has been adapted from material provided by Colorado State University.

Fausto Intilla

www.oloscience.com

Pedophiles Have Deficits In Brain Activation, Study Suggests

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http://www.sciencedaily.com/releases/2007/09/070920091209.htm

Science Daily — Pedophilia, the sexual attraction of adults to children, is a significant public health concern and it does not respond well to treatment. Additionally, the brain mechanisms underlying pedophilia are not well understood.
A new study being published in the September 15th issue of Biological Psychiatry is the first of its kind to use functional brain imaging to describe neural circuits contributing to pedophilia.
Using functional magnetic resonance imaging, or fMRI, Walter and colleagues report that pedophilic patients showed reduced activation of the hypothalamus, a brain region involved in regulating physiologic arousal and hormone release, as compared to healthy individuals when they were viewing sexually arousing pictures of adults.
Deficits of activation in the frontal cortex were associated with the extent of pedophilic behavior. In other words, when shown erotic pictures of adults, the brains of the pedophilic patients had reduced reactions in the pleasure center of the brain, indicating an altered sexual interest.
John H. Krystal, M.D., Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System, comments that, "the ability to intervene rationally in this disorder is limited by shortcomings in our understanding of its neurobiology. The findings provide clues to the complexity of this disorder, [and] this deficit may predispose individuals who are vulnerable to pedophilia to seek other forms of stimulation." It is important to acknowledge and consider however, that it is currently unknown "whether this pattern of brain activation is a risk factor for the development of pedophilia or a consequence of their pedophilic sexual experiences," according to Dr. Krystal, and future research will be needed.
One of the study's authors, Georg Northoff, M.D., Ph.D., adds, "[These findings] may open the door for better understanding the neurobiology of this disorder which is of forensic, criminal and public concern. Our results may thus be seen as the first step towards establishing a neurobiology of pedophilia which ultimately may contribute to the development of new and effective means of therapies for this debilitating disorder."
The article is "Pedophilia Is Linked to Reduced Activation in Hypothalamus and Lateral Prefrontal Cortex During Visual Erotic Stimulation" by Martin Walter, Joachim Witzel, Christine Wiebking, Udo Gubka, Michael Rotte, Kolja Schiltz, Felix Bermpohl, Claus Tempelmann, Bernhard Bogerts, Hans Jochen Heinze, and Georg Northoff. Drs. Walter, Wiebking, Schiltz, Bogerts and Northoff are with the Department of Psychiatry, Otto-von-Guericke University of Magdeburg, Germany, while Drs. Rotte, Tempelmann, and Heinze are with the Department of Neurology. Drs. Witzel and Gubka are affiliated with the State Hospital for Forensic Psychiatry of Saxonia Anhaltina, Germany. Dr. Bermpohl is with the Department of Psychiatry and Psychotherapy at Charité Medical School, University Medicine Berlin, Germany. The article appears in Biological Psychiatry, Volume 62, Issue 6 (September 15, 2007), published by Elsevier.
Note: This story has been adapted from a news release issued by Elsevier.

Fausto Intilla
www.oloscience.com

Brain Center For 'Sound Space' Identified

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http://www.sciencedaily.com/releases/2007/09/070919121602.htm

Science Daily — While the visual regions of the brain have been intensively mapped, many important regions for auditory processing remain terra incognita. Now, researchers have identified the region responsible for a key auditory process--perceiving "sound space," the location of sounds.

The findings settle a controversy in earlier studies that failed to establish the auditory region, called the planum temporale, as responsible for perceiving auditory space. Leon Y. Deouell and colleagues published their findings in the journal Neuron.
Studies by other researchers had shown that the planum temporale was activated when people were asked to perform tasks in which they located sounds in space. However, many researchers believed that the region was responsible only for intentional processing of such information. And in fact, previous studies had failed to establish that the planum temporale was responsible for automatic, nonintentional representation of spatial location.
However, Deouell and colleagues used an improved experimental design that enabled them to more sensitively determine the brain's auditory spatial location center. For example, they presented their human subjects with sounds against a background of silence, used headphones that more accurately reproduced sound location, used noise with a rich spectrum which has been shown to be more readily locatable in space, and created an individually tailored sound space for each subject by using sounds previously recorded directly from the subjects' own ears.
In their experiments, they presented bursts of the noise to the volunteers wearing the headphones while the subjects' brains were scanned by functional magnetic resonance imaging. In this widely used brain-scanning technique, harmless magnetic fields and radio waves are used to image blood flow in brain regions, which reflects brain activity in those locations.
The subjects were instructed to ignore the sounds. And, to divert their attention, they either watched a movie with the sound turned off or were given a simple button-pushing task.
When the position of the noise bursts was varied in space, the researchers found that the planum temporale in the subjects' brain was, indeed, activated. What's more, the greater the number of distinct sound locations subjects heard during test runs, the greater the activity in the planum temporale.
The researchers concluded that their experiments "suggest that neurons in this region represent, in a nonintentional or preattentive fashion, the location of sound sources in the environment." They wrote that "Space representation in this region may provide the neural substrate needed for an orientation response to critical auditory events and for linking auditory information with information acquired through other modalities."
The researchers include Leon Y. Deouell of The Hebrew University of Jerusalem and University of California at Berkeley; Aaron S. Heller of University of California at Berkeley; Rafael Malach of Weizmann Institute of Science in Rehovot; and Mark D'Esposito and Robert T. Knight of University of California at Berkeley.
This work was supported by NINDS Grant NS21135 to R.T.K. and an Israel Science Foundation grant 477-05 to L.Y.D.
Reference: Deouell et al.: "Cerebral Responses to Change in Spatial Location of Unattended Sounds." Publishing in Neuron 55, 985--996, September 20, 2007. DOI 10.1016/j.neuron.2007.08.019.
Note: This story has been adapted from a news release issued by Cell Press.

Fausto Intilla

www.oloscience.com

Brain Network Related To Intelligence Identified

Source:

http://www.sciencedaily.com/releases/2007/09/070911092117.htm

Science Daily — A primary mystery puzzling neuroscientists – where in the brain lies intelligence? – just may have a unified answer.

In a review of 37 imaging studies related to intelligence, including their own, Richard Haier of the University of California, Irvine and Rex Jung of the University of New Mexico have uncovered evidence of a distinct neurobiology of human intelligence. Their Parieto-Frontal Integration Theory (P-FIT) identifies a brain network related to intelligence, one that primarily involves areas in the frontal and the parietal lobes.
“Recent neuroscience studies suggest that intelligence is related to how well information travels throughout the brain,” said Haier, a professor of psychology in the School of Medicine and longtime human intelligence researcher. “Our review of imaging studies identifies the stations along the routes intelligent information processing takes. Once we know where the stations are, we can study how they relate to intelligence.”
The data suggest that some of the brain areas related to intelligence are the same areas related to attention and memory and to more complex functions like language. Haier and Jung say this possible integration of cognitive functions suggests that intelligence levels might be based on how efficient the frontal-parietal networks process information.
Brain imaging studies of intelligence are relatively new, with Haier doing some of the first ones only 20 years ago. Although there is still discussion about how to define and measure intelligence, Haier and Jung found surprising consistency in the studies they reviewed despite the fact the studies represented a variety of approaches.
A detailed report on this research including peer commentary from 19 researchers appears online in the journal Behavioral and Brain Sciences.
In his peer commentary, University of Washington psychologist Earl Hunt writes: “The Jung & Haier P-FIT model shows how far we have progressed toward understanding the biological basis of intelligence. Twenty-five years ago researchers in the field were engaged in an unedifying discussion of the relation between skull sizes and intelligence test scores. By taking advantage of the huge advances in measurement of the brain that have occurred in the past quarter century, [Jung and Haier] can take the far more sophisticated view that individual differences in intelligence depend, in part, upon individual differences in specific areas of the brain and in the connections between them.”
Haier and Jung have made some of the seminal findings in intelligence studies. In a 2004 study, they found that regions related to general intelligence are located throughout the brain and that a single “intelligence center,” such as the frontal lobe, is unlikely. And in a 2005 study, they found that while there are essentially no disparities in general intelligence between the sexes, women have more white matter and men more gray matter related to intelligence test scores, suggesting that no single neuroanatomical structure determines general intelligence and that different types of brain designs can produce equivalent intellectual performance.
“Genetic research has demonstrated that intelligence levels can be inherited, and since genes work through biology, there must be a biological basis for intelligence,” Haier said. “We have a long way to go before we understand the details, but our P-FIT model provides a framework for testing new hypotheses in future experiments.”
Note: This story has been adapted from a news release issued by University of California - Irvine.

Fausto Intilla

www.oloscience.com

Adult Brain Can Change, Study Confirms

Source:

http://www.sciencedaily.com/releases/2007/09/070905155440.htm

Science Daily — It is well established that a child's brain has a remarkable capacity for change, but controversy continues about the extent to which such plasticity exists in the adult human primary sensory cortex.

Now, neuroscientists from MIT and Johns Hopkins University have used converging evidence from brain imaging and behavioral studies to show that the adult visual cortex does indeed reorganize--and that the change affects visual perception.
The authors believe that as scientists find ways to use this adaptive ability, the work could have relevance to topics ranging from learning to designing interventions for improving recovery following stroke, brain injury, or visual disorders.
Animal studies conducted two decades ago and using single cell recording of neurons found that the adult animal brain can change, but shed little information about the adult human brain. In 2005, a functional magnetic resonance imaging (fMRI) study led by Professor Nancy Kanwisher at the McGovern Institute for Brain Research at MIT found evidence of plasticity in the visual cortex of adults with macular degeneration, an eye disease that deprives regions of the cortex of visual information.
But another fMRI study of macular degeneration found no such evidence, and an animal study using both single cell recordings and fMRI also questioned the 20-year-old animal work.
Lead author Daniel Dilks, a postdoctoral associate in Kanwisher's lab who conducted the current work while a graduate student at Johns Hopkins in senior author Michael McCloskey's lab, jumped into the fray when he found BL, a stroke patient.
BL's stroke damaged the optic radiation fibers, which transmit information from the eye to the primary visual cortex, but the cortex itself remained intact. The damage eliminated input from the upper left visual field to the corresponding region of the primary visual cortex, thereby depriving a region of cortex and creating a blind area in the upper left visual field.
The researchers wanted to find out what happened to that deprived piece of cortex. "We discovered that it took on new functional properties, and BL sees differently as a consequence of that cortical reorganization," explains Dilks.
BL had reported that things "looked distorted" in the lower left visual field (below his blind area). The researchers hypothesized that the distortions resulted from cortical reorganization in the deprived cortex. To isolate that distortion, they had BL fixate on a center dot while objects, such as squares, appeared in various parts of the visual field. As expected, BL saw nothing when a square appeared in his blind area.
But when the square appeared just below the blind area, he perceived the square as a rectangle extending upwards into the blind area. Likewise, he saw triangles as "pencil-like", and circles as "cigar-like".
Subsequent fMRI studies confirmed that the visually deprived cortex (representing the upper left visual field) was responding to information coming from the lower left visual field. The deprived cortex assumed new properties, a hallmark of plasticity, and that explained the visual distortions.
Dilks is continuing this work in postdoctoral studies in Kanwisher's lab. In addition to Michael McCloskey, John Serences of University of California Irvine, and Benjamin Rosenau and Steven Yantis, both of Johns Hopkins, coauthored the Journal of Neuroscience paper. An Integrative Graduate Education and Research Traineeship and a Graduate Research Fellowship, both from the National Science Foundation, and the NIH funded the Johns Hopkins work.
The study appears online Sept. 5 in an advance publication of the Journal of Neuroscience.
Note: This story has been adapted from a news release issued by Massachusetts Institute of Technology.

Fausto Intilla

www.oloscience.com