Brain Activity Differs For Creative And Noncreative Thinkers

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http://www.sciencedaily.com/releases/2007/10/071027102409.htm

ScienceDaily (Oct. 29, 2007) — Why do some people solve problems more creatively than others? Are people who think creatively different from those who tend to think in a more methodical fashion?
These questions are part of a long-standing debate, with some researchers arguing that what we call “creative thought” and “noncreative thought” are not basically different. If this is the case, then people who are thought of as creative do not really think in a fundamentally different way from those who are thought of as noncreative. On the other side of this debate, some researchers have argued that creative thought is fundamentally different from other forms of thought. If this is true, then those who tend to think creatively really are somehow different.
A new study led by John Kounios, professor of Psychology at Drexel University and Mark Jung-Beeman of Northwestern University answers these questions by comparing the brain activity of creative and noncreative problem solvers. The study, published in the journal Neuropsychologia, reveals a distinct pattern of brain activity, even at rest, in people who tend to solve problems with a sudden creative insight -- an “Aha! Moment” – compared to people who tend to solve problems more methodically.
At the beginning of the study, participants relaxed quietly for seven minutes while their electroencephalograms (EEGs) were recorded to show their brain activity. The participants were not given any task to perform and were told they could think about whatever they wanted to think about. Later, they were asked to solve a series of anagrams – scrambled letters that can be rearranged to form words [MPXAELE = EXAMPLE]. These can be solved by deliberately and methodically trying out different letter combinations, or they can be solved with a sudden insight or “Aha!” in which the solution pops into awareness. After each successful solution, participants indicated in which way the solution had come to them.
The participants were then divided into two groups – those who reported solving the problems mostly by sudden insight, and those who reported solving the problems more methodically – and resting-state brain activity for these groups was compared. As predicted, the two groups displayed strikingly different patterns of brain activity during the resting period at the beginning of the experiment – before they knew that they would have to solve problems or even knew what the study was about.
One difference was that the creative solvers exhibited greater activity in several regions of the right hemisphere. Previous research has suggested that the right hemisphere of the brain plays a special role in solving problems with creative insight, likely due to right-hemisphere involvement in the processing of loose or “remote” associations between the elements of a problem, which is understood to be an important component of creative thought. The current study shows that greater right-hemisphere activity occurs even during a “resting” state in those with a tendency to solve problems by creative insight. This finding suggests that even the spontaneous thought of creative individuals, such as in their daydreams, contains more remote associations.
Second, creative and methodical solvers exhibited different activity in areas of the brain that process visual information. The pattern of “alpha” and “beta” brainwaves in creative solvers was consistent with diffuse rather than focused visual attention. This may allow creative individuals to broadly sample the environment for experiences that can trigger remote associations to produce an Aha! Moment.
For example, a glimpse of an advertisement on a billboard or a word spoken in an overheard conversation could spark an association that leads to a solution. In contrast, the more focused attention of methodical solvers reduces their distractibility, allowing them to effectively solve problems for which the solution strategy is already known, as would be the case for balancing a checkbook or baking a cake using a known recipe.
Thus, the new study shows that basic differences in brain activity between creative and methodical problem solvers exist and are evident even when these individuals are not working on a problem. According to Kounios, “Problem solving, whether creative or methodical, doesn’t begin from scratch when a person starts to work on a problem. His or her pre-existing brain-state biases a person to use a creative or a methodical strategy.”
In addition to contributing to current knowledge about the neural basis of creativity, this study suggests the possible development of new brain imaging techniques for assessing potential for creative thought, and for assessing the effectiveness of methods for training individuals to think creatively.
Journal reference: Kounios, J., Fleck, J.I., Green, D.L., Payne, L., Stevenson, J.L., Bowden, E.M., & Jung-Beeman, M. The origins of insight in resting-state brain activity, Neuropsychologia (2007), doi:10.1016/j.neuropsychologia.2007.07.013
See also:
Jung-Beeman, M., Bowden, E.M., Haberman, J., Frymiare, J.L., Arambel-Liu, S., Greenblatt, R., Reber, P.J., & Kounios, J. (2004). Neural activity when people solve verbal problems with insight. PLoS Biology, 2, 500-510.
Kounios, J., Frymiare, J.L., Bowden, E.M., Fleck, J.I., Subramaniam, K., Parrish, T.B., & Jung-Beeman, M.J. (2006). The prepared mind: Neural activity prior to problem presentation predicts subsequent solution by sudden insight. Psychological Science, 17, 882-890.
Adapted from materials provided by Drexel University.

Fausto Intilla
www.oloscience.com

What Are The Early Warning Signs Of Autism?

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http://www.sciencedaily.com/releases/2007/10/071029120427.htm

ScienceDaily (Oct. 29, 2007) — Two new clinical reports from the American Academy of Pediatrics will help pediatricians recognize autism spectrum disorders (ASDs) earlier and guide families to effective interventions, which will ultimately improve the lives of children with ASDs and their families. The first clinical report, “Identification and Evaluation of Children With Autism Spectrum Disorders,” provides detailed information on signs and symptoms so pediatricians can recognize and assess ASDs in their patients. Language delays usually prompt parents to raise concerns to their child’s pediatrician – usually around 18 months of age. However, there are earlier subtle signs that if detected could lead to earlier diagnosis.
These include:
not turning when the parent says the baby’s name;
not turning to look when the parent points says, “Look at…” and not pointing themselves to show parents an interesting object or event;
lack of back and forth babbling;
smiling late; and
failure to make eye contact with people.
Most children, at some time during early development, form attachments with a stuffed animal, special pillow or blanket. Children with ASDs may prefer hard items (ballpoint pens, flashlight, keys, action figures, etc.). They may insist on holding the object at all times.
The report advises pediatricians to be cognizant of signs of ASD, as well as other developmental concerns, at every well-child visit by simply asking the parents if they or their child’s other caregivers have any concerns about their child’s development or behavior. If concerns are present that may relate to ASD, the clinician is advised to use a standardized screening tool. The report also introduces universal screening, which means pediatricians conduct formal ASD screening on all children at 18 and 24 months regardless of whether there are any concerns.
“Red Flags” that are absolute indications for immediate evaluation include: no babbling or pointing or other gesture by 12 months; no single words by 16 months; no two-word spontaneous phrases by 24 months; and loss of language or social skills at any age. Early intervention can make a huge difference in the child’s prognosis. “Autism doesn’t go away, but therapy can help the child cope in regular environments,” said Chris Plauche Johnson, MD, MEd, FAAP, and co-author of the reports. “It helps children want to learn and communicate.”
Educational strategies and associated therapies, which are the cornerstones of treatment for ASDs, are reviewed in the second AAP clinical report, “Management of Children With Autism Spectrum Disorders.” Early intervention is crucial for effective treatment. The report strongly advises intervention as soon as an ASD diagnosis is seriously considered rather than deferring until a definitive diagnosis is made. The child should be actively engaged in intensive intervention at least 25 hours per week, 12 months per year with a low student-to-teacher ratio allowing for sufficient one-on-one time. Parents should also be included.
Pediatricians who treat children with ASDs should recognize that many of their patients will use nonstandard therapies. The report says it’s important for pediatricians to become knowledgeable about complementary and alternative medicine (CAM) therapies, ask families about current and past CAM use, and provide balanced information and advice about treatment options, including identifying risks or potential harmful effects. They should avoid becoming defensive or dismissing CAM in ways that convey a lack of sensitivity or concern, but they should also help families to understand how to evaluate scientific evidence and recognize unsubstantiated treatments.
“Many parents are interested in CAM treatments such as various vitamin and mineral supplements, chelation therapy, and diet restrictions. It’s important for pediatricians to maintain open communication and continue to work with these families even if there is disagreement about treatment choices, ” said co-author of the reports Scott M. Myers, MD, FAAP. “At the same time, it’s also important to critically evaluate the scientific evidence of effectiveness and risk of harm and convey this information to the families, just as one should for treatment with medication and for non-medical interventions.”
Although use of the gluten-free/casein-free diet for children with ASDs is popular, there is little evidence to support or refute this intervention. More studies are in progress, and it is anticipated that these studies will provide substantially more useful information regarding the efficacy of the gluten-free/casein-free diet.
Tantrums, aggressive behaviors, and self-injury are common among children with ASDs, and medical factors may cause or exacerbate these behaviors. Behavior management strategies are often the most effective treatment for challenging behaviors. In some children, medications are effective in addition to the behavioral strategies. The report addresses the medical issues that some children with ASDs encounter such as seizures, gastrointestinal problems, and sleep disturbance, and provides guidance for medication management.
Both reports will also be part of the new AAP practical resource for pediatricians "AUTISM: Caring for Children with Autism Spectrum Disorders: A Resource Toolkit for Clinicians,” which includes screening and surveillance tools, guideline summary charts, management checklists, developmental checklists, developmental growth charts, early intervention referral forms and tools, sample letters to insurance companies and family handouts.
Adapted from materials provided by American Academy of Pediatrics.

Fausto Intilla
www.oloscience.com

Humans Perceive Others' Fear Faster Than Other Emotions

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http://www.sciencedaily.com/releases/2007/10/071014081055.htm

Science Daily — You may not be fully dressed without a smile, but a look of horror will make a faster first impression. Vanderbilt University researchers have discovered that the brain becomes aware of fearful faces more quickly than those showing other emotions.

"There are reasons to believe that the brain has evolved mechanisms to detect things in the environment that signal threat. One of those signals is a look of fear," David Zald, associate professor of psychology and a co-author of the new study, said. "We believe that the brain can detect certain cues even before we are aware of them, so that we can direct our attention to potentially threatening situations in our environment."
Randolph Blake, Centennial Professor of Psychology, and Eunice Yang, doctoral student, were co-authors of the study, which will appear in the November 2007 issue of Emotion.
The researchers set out to determine if we become aware of fearful, neutral or happy expressions at the same speed, or if one of these expressions reaches our awareness faster than the others. To do this, they needed to find a way to slow down the speed at which subjects processed facial information -- which usually takes less than 40 milliseconds. At those high speeds it is difficult to tell which images rise to awareness the fastest.
Yang, the lead author of the study, realized that a technique being used in Blake's lab might provide a solution to the problem. The technique, continuous flash suppression, keeps people from becoming aware of what they are seeing for up to 10 seconds. Using this technique, the team had research subjects look at a screen through a viewer, similar to the eyepieces on a microscope, which allowed different images to be presented to each eye.
Many images were rapidly presented to one eye while a static image of a face was presented to the other. The multiple images served as visual 'noise,' suppressing the image of the face. The subjects indicated when they first became aware of seeing a face, enabling the researchers to determine if the expression on the face had any impact on how quickly the subject became aware of it.
The team found that subjects became aware of faces that had fearful expressions before neutral or happy faces. They believe a brain area called the amygdala, which shortcuts the normal brain pathway for processing visual images, is responsible.
"The amygdala receives information before it goes to the cortex, which is where most visual information goes first. We think the amygdala has some crude ability to process stimuli and that it can cue some other visual areas to what they need to focus on," Zald said.
Zald and his colleagues believe the eyes of the fearful face play a key role.
"Fearful eyes are a particular shape, where you get more of the whites of the eye showing," he said."That may be the sort of simple feature that the amygdala can pick up on, because it's only getting a fairly crude representation. That fearful eye may be something that's relatively hardwired in there."
A surprising finding was that subjects perceived happy faces the slowest.
"What we believe is happening is that the happy faces signal safety. If something is safe, you don't have to pay attention to it," Zald said.
Next, the researchers will explore how this information influences our behavior.
"We are interested in now exploring what this means for behavior," Yang said. "Since these expressions are being processed without our awareness, do they affect our behavior and our decision making? If so, how?"
The research was supported by funding from the National Institutes of Health. Blake and Zald are Vanderbilt Kennedy Center for Research on Human Development investigators.
Note: This story has been adapted from material provided by Vanderbilt University.

Fausto Intilla

www.oloscience.com

Why Emotionally Charged Events Are So Memorable

Source:

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

Black Gay Men, Lesbians, Have Fewer Mental Disorders Than Whites, Says Study

Source:

http://www.sciencedaily.com/releases/2007/10/071002111541.htm

Science Daily — According to a study conducted at Columbia University's Mailman School of Public Health among lesbian, gay, and bisexual populations, blacks and Latinos do not have more mental disorders than whites. Based on the theory that stress related to prejudice would increase risk for mental disorders, researchers typically expect that black lesbians, gay men, and bisexuals face prejudice related to both racism and homophobia and therefore would have more disorders than their white counterparts.
Contrary to this expectation, however, the Mailman School study found that black lesbians, gay men, and bisexuals had significantly fewer disorders than white individuals. Latinos had a prevalence of disorders similar to whites.
"These findings suggest that black lesbians, gay men, and bisexuals have effective ways to cope with prejudice related to racism and homophobia" noted Ilan H. Meyer, PhD, associate professor of clinical Sociomedical Sciences at the Mailman School of Public Health and principal investigator of the study.
The study of 388 white, black and Latino New York City residents aged 18 -- 59 who identified themselves as lesbian, gay, or bisexual is the first population-based study of its kind to examine the prevalence of mental disorders among black and Latino, versus white, lesbians, gay men, and bisexual individuals.
By contrast to the findings about mental disorders, more black and Latino gay men, lesbians, and bisexuals than whites reported a history of serious suicide attempts. "Because these suicide attempts occurred at an early age, typically during the teenage, we can speculate that they coincided with a coming-out period and were related to the social disapprobation afforded to lesbian, gay, and bisexual identities," Dr. Meyer said.
The findings were consistent with the notion that these problems may be more potent among lesbians, gay men, and bisexual youth in Latino and other communities of color. "In the absence of higher prevalence of mood disorders in this population, these findings pose challenge to mental health professionals" said Dr. Meyer. "If this is indeed the case, public health professionals should address what prevention efforts are required to reduce suicide risk among lesbian, gay, and bisexual youths in these communities," Dr. Meyer said.
The study also found that, across all race/ethnic groups, younger cohorts of lesbians, gay men, and bisexuals (those in age groups 18 -- 29 and 30 -- 44 as compared with 45 -- 59 years old) had lower prevalence of almost all mental disorders categories, and the difference was statistically significant for mood disorders. Younger cohorts also had fewer serious suicide attempts than did older cohorts (but this was statistically significant only for the middle cohort).
"The finding regarding younger cohorts of lesbians, gay men, and bisexuals is consistent with social stress theories that predicted that the liberalization of social attitudes toward homosexuality over the past few decades can lead to a decline in stress and related mental disorders and suicide among lesbians, gay men, and bisexual individuals," said Dr. Meyer.
In other findings, the study reported that bisexual identity was related to higher prevalence of substance use disorders but not of anxiety or mood disorders and it confirmed previous observations that among gay populations, men and women do not differ substantially in disorder prevalence.
The findings will be reported in the November 2007 American Journal of Public Health.
The study was funded by the National Institute of Mental Health.
Note: This story has been adapted from material provided by Columbia University's Mailman School of Public Health.

Fausto Intilla
www.oloscience.com

Parents May Underestimate Children's Difficulties Falling Asleep

Source:

http://www.sciencedaily.com/releases/2007/10/071001081632.htm

Science Daily — Children have more difficulty initiating sleep than maintaining sleep. Further, parents tend to underestimate their children's sleep problems. This highlights the importance of having treatment options available to help a child overcome a sleep disorder, according to a study published in the October 1 issue of the journal Sleep.
The study, authored by Leonie Fricke-Oerkermann, PhD, of the University of Cologne in Germany, centered on 832 children and their parents, who were surveyed using questionnaires three times on an annual basis. The average age of the children was 9.4, 10.7 and 11.7 years at the three assessments.
According to the results, in child and parental reports, about 30 to 40 percent of the children had problems falling asleep at the first assessment. One year later, the child and parental reports indicated that about 60 percent of those children continued to have difficulties initiating sleep.
One of the striking results of the study, notes Dr. Fricke-Oerkermann, is the difference between the children and their parents in the assessment of the children's sleep problems. Children described significantly more difficulties initiating and maintaining sleep than what their parents reported on their behalf.
For example, in the parental reports, four to six percent of the children "often" had difficulties initiating sleep, whereas up to five to 10 percent of the children reported difficulties initiating sleep. About 40 percent of the children reported difficulties initiating sleep which occur "sometimes", compared to 25 to 30 percent of what the parents reported for their children. Sleep onset problems in all surveys were present in 13.5 percent of the children according to their parents and 24 percent of the children according to the children's ratings.
These findings are supported by other studies, and imply that in epidemiological studies and in practical work, the inclusion of children's and adolescent's self-reports is necessary. It might be that parents are not informed about the sleep problems by their child, Dr. Fricke-Oerkermann speculates. On the other hand, it might be that children in this age range have difficulties estimating the severity of their sleep problems.
Difficulties maintaining sleep are less common, with three percent (parent-reported) versus six percent (child-reported). These results indicate that children of this age group have a higher risk of developing difficulties initiating sleep than difficulties maintaining sleep after one year, adds Dr. Fricke-Oerkermann.
"Sleep problems in childhood and adolescence are a frequent phenomenon," says Dr. Fricke-Oerkermann. "Sleep problems decrease only marginally with age. Sleep problems might become chronic, requiring medical treatment."
It is recommended that children in pre-school sleep between 11-13 hours a night, school-aged children between 10-11 hours of sleep a night, and adolescents about nine hours a night.
The American Academy of Sleep Medicine (AASM) offers some tips to help your child sleep better:
Follow a consistent bedtime routine. Set aside 10 to 30 minutes to get your child ready to go to sleep each night.
Establish a relaxing setting at bedtime.
Interact with your child at bedtime. Don't let the TV, computer or video games take your place.
Keep your children from TV programs, movies, and video games that are not right for their age.
Do not let your child fall asleep while being held, rocked, fed a bottle, or while nursing.
At bedtime, do not allow your child to have foods or drinks that contain caffeine. This includes chocolate and sodas. Try not to give him or her any medicine that has a stimulant at bedtime. This includes cough medicines and decongestants.
Children are encouraged to inform their parents of any sleep problems they may have. Parents who suspect that their child might be suffering from a sleep disorder are encouraged to consult with their child's pediatrician or a sleep specialist.
Article: "Prevalence and Course of Sleep Problems in Childhood"
Note: This story has been adapted from material provided by American Academy of Sleep Medicine.

Fausto Intilla
www.oloscience.com

Genes May Hold The Keys To How Humans Learn

Source:

http://www.sciencedaily.com/releases/2007/10/071001172835.htm

Science Daily — New research is giving scientists fresh insights into how genetics are a prime factor in how we learn.
Michael Frank, an assistant professor of psychology and director of the Laboratory for Neural Computation and Cognition at The University of Arizona, headed a team whose results are reported in the Oct. 1 issue of Early Edition, an online site hosted by the Proceedings of the National Academy of Sciences.
Frank and his colleagues found links to learning behaviors in three separate genes associated with dopamine. Dopamine is a neurotransmitter, a chemical in the brain that is often associated with pleasure, learning and other behaviors. Several neurological disorders, such as Parkinson's disease, are also linked to abnormal levels of dopamine.
Frank's study points to fundamental genetic differences between "positive" and "negative" learners.
"All three genes affect brain dopamine functioning, but in different ways, and in different parts of the brain" Frank said. "The genes predicted people's ability to learn from both the positive and negative outcomes of their decisions."
Two of the genes - DARPP-32 and DRD2 - predicted learning about the average, long-term probability of rewards and punishments, not unlike your personal preference for why, for example, you might choose steak over salmon.
"When making these kinds of choices, you do not explicitly recall each individual positive and negative outcome of all of your previous such choices. Instead, you often go with your 'gut,' which may involve a more implicit representation of the probability of rewarding outcomes based on past experience," Frank said.
The DARPP-32 and DRD2 genes control dopamine function in a region of the brain called the striatum, thought to be necessary for this kind of implicit reward learning. A third gene, COMT, did not predict long-term reward or punishment learning, but instead predicted a person's tendencies to change choice strategies after a single instance of negative feedback. Frank said this gene affects dopamine function in the prefrontal cortex of the brain, the area associated with conscious processing and working memory. This would be akin to switching from steak to salmon upon remembering your last experience with overdone steak.
The overall research program was designed to test a computer model that simulates the key roles of dopamine in reinforcement learning in different parts of the brain, as motivated by a body of biological research.
"The reason we looked at these three individual genes in the first place, out of a huge number of possible genes, is that we have a computer model that examines how dopamine mediates these kinds of reinforcement processes in the striatum and prefrontal cortex," Frank said. "The model makes specific predictions on how subtle changes in different aspects of dopamine function can affect behavior, and one way to get at this question is to test individual genes."
Among the evidence incorporated in the model and motivating the genetic study is research showing that bursts of dopamine production follow in the wake of unexpected rewards. Conversely, dopamine production declines when rewards are expected but not received.
To test their hypothesis, the researchers collected DNA from 69 healthy individuals who were asked to perform a computerized learning program. The volunteers were asked to pick one of two Japanese characters that appeared on a screen and were "rewarded" for a "correct" response, and "punished" for an "incorrect" one.
Frank said more research is needed to confirm that genetic effects are accompanied by brain-related changes in behavior. But, he said, the research offers insights into the genetic basis for learning differences and insights into improving human cognition and learning, both normal and abnormal.
"Understanding how dopaminergic variations affects learning and decision-making processes may have substantial implications for patient populations, such as (those with) Parkinson's disease, attention-deficit hyperactivity disorder (ADHD) and schizophrenia," Frank said. "The genetics might also help us identify individuals who might gain from different types of learning environments in the classroom."
Note: This story has been adapted from material provided by University of Arizona.

Fausto Intilla
www.oloscience.com

Native Language Governs The Way Toddlers Interpret Speech Sounds

Source:

http://www.sciencedaily.com/releases/2007/10/071001172817.htm

Science Daily — Toddlers are learning language skills earlier than expected and by the age of 18 months understand enough of the lexicon of their own language to recognize how speakers use sounds to convey meaning.
They also ignore sounds that don't play a significant role in speaking their native tongue, according to a study by a University of Pennsylvania psychologist.
The study shows how important the child's first year is in acquiring language. By listening to their parents and learning words, children discover how speech in their language works, a process that is vital for gaining command of vocabulary and grammar.
This is the first time scientists have shown that children as young as 18 months actively interpret the phonetic characteristics of their particular language when they learn words. Previously, scientists had speculated that this ability would emerge much later in life, once children had already amassed large vocabularies.
Previous research showed that at birth infants can distinguish most of the phonetic contrasts used by all the world's languages. This ''universal'' capacity shifts over the first year to a language-specific pattern in which infants retain or improve categorization of native-language sounds but fail to discriminate many non-native sounds. Eventually, they learn to ignore subtle speech distinctions that their language does not use.
This is why Japanese toddlers, like Japanese adults, cannot tell apart the English "r" and "l" sounds and why English speakers have trouble with certain French vowels because they all sound the same to non-native speakers due to language learning in infancy. The Penn study shows that even when two words sound very different, toddlers know whether to take this difference seriously or to chalk it up to random variation depending on how their language works.
"The results demonstrate that at 18 months children have a rudimentary understanding of the 'sound system' of their language and that knowledge guides their interpretation of the sounds they encounter," said Daniel Swingley, assistant professor in the Department of Psychology at Penn who worked with colleagues from the University of British Columbia and the Max-Planck-Institute for Psycholinguistics.
"Children can easily hear how the same word can be pronounced in different ways. We might say, 'Is that your kiiiiiitty"' or, 'Show me the kitty.' In English, we're still talking about the same cat. But children have to figure this out. In other languages, like Japanese or Finnish, those two versions of "kitty" could mean completely different things. Our study showed that 18-month-olds have already learned this and apply that knowledge when learning new words."
Psychologists tested vowel duration ("kitty" versus "kiiiitty") in three experiments comparing Dutch- and English-learning 18-month-olds. Children were shown two different toys. With one toy, researchers repeated a word dozens of times, naming it a "tam." The other toy was named too, with the same label only with the vowel acoustically longer in duration ("taam").
Dutch children, learning a language that includes words differentiated by how long the vowel is pronounced, interpret the variations as meaningful and learn which word goes with each object. English speakers ignored the elongation of vowel sounds.
English learners did not somehow lack the cognitive power to learn both words. They can hear the difference between the words, and they succeed on words that really are different in English ("tam" vs. "tem"). The difference arose from the phonological generalizations children had already made from their brief experience with English: "tam" and "taam", like "kitty" and "kiiiitty", mean the same thing. Dutch children, on the other hand, interpreted vowel duration as lexically contrastive in keeping with the properties of their language.
The study, to appear in the Oct. 1 issue of the Proceedings of the National Academy of Sciences, was funded by the Max-Planck-Gesellschaft, the Nederlandse Organisatie voor Wetenschappelijk Onderzoek's Spinoza Prize, the National Science Foundation, the National Institutes of Health and the Canadian Natural Sciences and Engineering Research Council.
The study was performed by Swingley, Christiane Dietrich of the Max-Planck-Institute for Psycholinguistics and Janet F. Werker of the University of British Columbia.
Note: This story has been adapted from material provided by University of Pennsylvania.

Fausto Intilla
www.oloscience.com

Female Anxiety: Females More Likely To Believe Negative Past Events Predict Future

Source:

http://www.sciencedaily.com/releases/2007/09/070928092126.htm

Science Daily — A new study finds that young girls and women are more likely to believe that negative past events predict future events, compared to boys and men. And that, according to researchers, may help explain why females have more frequent and intense worries, perceive more risk, have greater intolerance for uncertainty, and experience higher rates of anxiety than males.
The findings, from studies conducted at the University of California, Davis, are published in the journal Child Development.
In two studies involving 128 people, a researcher investigated 3- to 6-year-olds' as well as adults' knowledge that worry and preventative behaviors can be caused by thinking that a negative event from the past will or might reoccur in the future. The ability to explain emotions and behaviors in relation to past events is considered a fundamental part of adult social understanding that is important for processing past trauma, assessing risk, and making decisions.
In the first study, participants listened to six stories featuring characters that experienced negative events and then, many days later, felt worried or changed their behaviors when they saw the person or animal that had caused them prior harm. Children and adults were asked to explain the cause of the character's worry or behavior and then to predict how a naïve friend would react to the same situation.
The second study was the same as the first, except that the person or animal in the final scene only looked similar to the one that had caused harm in the past. In addition, for some trials, participants were asked to predict how the character was likely to respond to seeing this new person or animal.
Although there were no gender differences in the frequency with which participants provided past-to-future explanations, in both studies, female children and adults more frequently explained characters' reactions as motivated by possible versus certain harm (that is, what might happen versus what will happen). Moreover, female children and adults more frequently predicted that characters who encountered "similar perpetrators" would feel worried because they thought the new person or animal might cause the same harm as the one from the past.
The studies also found that children and adults believe negative past events forecast negative future events, even when the person or animal only resembles the past perpetrator of harm. Between 3 and 6 years of age, children increasingly understand that people's worry and behavior can be caused by allowing memories about past negative events to influence their anticipation of the future, and they are more aware that others who didn't experience or know about the negative past would feel differently and make different decisions.
"These results are significant because they reveal that knowledge about the impact of past-to-future thinking on emotions and behaviors develops during the preschool years," according to Kristin Hansen Lagattuta, assistant professor of psychology, a researcher at the Center for Mind and Brain at the University of California, Davis, and the author of the study.
Summarized from Child Development, Vol. 78, Issue 5, Thinking About the Future Because of the Past: Young Children's Knowledge About the Causes of Worry and Preventative Decisions by Lagattuta, KH (University of California, Davis).
Note: This story has been adapted from material provided by Society for Research in Child Development.

Fausto Intilla
www.oloscience.com