Glia cells also regulate learning and memory, new Tel Aviv University research finds     

Glia cells, named for the Greek word for "glue," hold the brain's neurons together and protect the cells that determine our thoughts and behaviors, but scientists have long puzzled over their prominence in the activities of the brain dedicated to learning and memory. Now Tel Aviv University researchers say that glia cells are central to the brain's plasticity — how the brain adapts, learns, and stores information. According to Ph.D. student Maurizio De Pittà of TAU's Schools of Physics and Astronomy and Electrical Engineering, glia cells do much more than hold the brain together. A mechanism within the glia cells also sorts information for learning purposes, De Pittà says. "Glia cells are like the brain's supervisors. By regulating the synapses, they control the transfer of information between neurons, affecting how the brain processes information and learns."

De Pittà's research, led by his TAU supervisor Prof. Eshel Ben-Jacob, along with Vladislav Volman of The Salk Institute and the University of California at San Diego and Hugues Berry of the Université de Lyon in France, has developed the first computer model that incorporates the influence of glia cells on synaptic information transfer. Detailed in the journal PLoS Computational Biology, the model can also be implemented in technologies based on brain networks such as microchips and computer software, Prof. Ben-Jacob says, and aid in research on brain disorders such as Alzheimer's disease and epilepsy.

Regulating the brain's "social network"

The brain is constituted of two main types of cells: neurons and glia. Neurons fire off signals that dictate how we think and behave, using synapses to pass along the message from one neuron to another, explains De Pittà. Scientists theorize that memory and learning are dictated by synaptic activity because they are "plastic," with the ability to adapt to different stimuli. But Ben-Jacob and colleagues suspected that glia cells were even more central to how the brain works. Glia cells are abundant in the brain's hippocampus and the cortex, the two parts of the brain that have the most control over the brain's ability to process information, learn and memorize. In fact, for every neuron cell, there are two to five glia cells. Taking into account previous experimental data, the researchers were able to build a model that could resolve the puzzle.

The brain is like a social network, says Prof. Ben-Jacob. Messages may originate with the neurons, which use the synapses as their delivery system, but the glia serve as an overall moderator, regulating which messages are sent on and when. These cells can either prompt the transfer of information, or slow activity if the synapses are becoming overactive. This makes the glia cells the guardians of our learning and memory processes, he notes, orchestrating the transmission of information for optimal brain function.

New brain-inspired technologies and therapies

The team's findings could have important implications for a number of brain disorders. Almost all neurodegenerative diseases are glia-related pathologies, Prof. Ben-Jacob notes. In epileptic seizures, for example, the neurons' activity at one brain location propagates and overtakes the normal activity at other locations. This can happen when the glia cells fail to properly regulate synaptic transmission. Alternatively, when brain activity is low, glia cells boost transmissions of information, keeping the connections between neurons "alive."

The model provides a "new view" of how the brain functions. While the study was in press, two experimental works appeared that supported the model's predictions. "A growing number of scientists are starting to recognize the fact that you need the glia to perform tasks that neurons alone can't accomplish in an efficient way," says De Pittà. The model will provide a new tool to begin revising the theories of computational neuroscience and lead to more realistic brain-inspired algorithms and microchips, which are designed to mimic neuronal networks.

Pro: Studies show that spanking, properly utilized, can lead to well-adjusted children. Con: Spanking is harmful and can hinder kids later in life. [read article from latimes.com]

New analysis casts doubt on results of tobacco industry studies into safety of cigarette additives

Published tobacco industry scientific research on the safety of cigarette additives cannot be taken at face value, according to an analysis led by Stanton Glantz from the Center for Tobacco Control Research and Education at the University of California in San Francisco, and published in this week's PLoS Medicine. In the PLoS Medicine study, the authors reanalyzed data from "Project MIX" in which chemical analyses of smoke, and the potential toxicity of 333 cigarette additives were conducted by scientists from the tobacco company Philip Morris. The results of these analyses were published in Food and Chemical Toxicology in 2002.

The authors of the independent analysis used documents made public as a result of litigation against the tobacco industry to investigate the origins and design of Project MIX, and to conduct their own analyses of the results. Internal documents revealed post-hoc changes in analytical protocols after the industry scientists found that the additives increased cigarette toxicity by increasing the number of particles in the cigarette smoke. Crucially, the authors also found that in the original Project MIX analysis, the published papers obscured findings of toxicity by adjusting the data by Total Particulate Matter concentration: when the authors conducted their own analysis by studying additives per cigarette, they found that 15 carcinogenic chemicals increased by 20% or more. The authors also found that the failure to identify many toxic biological effects was because the studies Philip Morris carried out were too small to reliably detect toxic effects.

The authors conclude that their independent analysis provides evidence for the elimination of the use of the studied additives (including menthol) from cigarettes on public health grounds. The authors say: "The results demonstrate that toxins in cigarette smoke increase substantially when additives are put in cigarettes, including the level of [Total Particulate Matter]. In particular, regulatory authorities, including the [Food and Drug Administration] and similar agencies elsewhere, could use the Project MIX data to eliminate the use of these 333 additives (including menthol) from cigarettes."

School absenteeism is a significant problem, and students who are frequently absent from school more often have symptoms of psychiatric disorders. A new longitudinal study of more than 17,000 youths has found that frequently missing school is associated with a higher prevalence of mental health problems later on in adolescence, and that mental health problems during one year also predict missing additional school days in the following year for students in middle and high school. The study, published in the journal Child Development, was conducted by researchers at the University of California, Los Angeles (UCLA), the University of Florida, Boston University, the Child and Adolescent Services Research Center, the Oregon Social Learning Center, and Johns Hopkins University. "We've long known that students who are frequently absent from school are more likely to have symptoms of psychiatric disorders, but less clear is the reason why," says Jeffrey Wood, associate professor of educational psychology and psychiatry at UCLA, who led the study. "These two aspects of youths' adjustment may at times exacerbate one another, leading over the course of time to more of each."

The study found that between grades 2 and 8, students who already had mental health symptoms (such as antisocial behavior or depression) missed more school days over the course of a year than they had in the previous year and than students with few or no mental health symptoms. Conversely, middle and high school students who were chronically absent in an earlier year of the study tended to have more depression and antisocial problems in subsequent years. For example, 8th graders who were absent more than 20 days were more likely to have higher levels of anxiety and depression in 10th grade than were 8th graders who were absent fewer than 20 days.

"The findings can help inform the development of programs to reduce school absenteeism," according to Wood. "School personnel in middle schools and high schools could benefit from knowing that mental health issues and school absenteeism each influence the other over time. Helping students address mental health issues may in turn help prevent the emergence of chronic absenteeism. At the same time, working to help students who are developing a pattern of chronic absenteeism come to school more consistently may help prevent psychiatric problems." The researchers looked at more than 17,000 children in 1st through 12th grades using three datasets: the National Longitudinal Study of Adolescent Health, a longitudinal study of a nationally representative sample of adolescents in grades 7 to 12; the Johns Hopkins Prevention Intervention Research Center Study, a longitudinal study of classroom-based interventions involving children in grades 1 to 8; and the Linking the Interests of Families and Teachers trial, a longitudinal study of children in grades 1 through 12. Researchers interviewed students and parents annually or biennially, and they gathered information from school attendance records. In addition, students, parents, and teachers filled out questionnaires.

New Caledonian crows have, in the past, distinguished themselves with their advanced tool using abilities. A team of researchers from the University of Auckland and the University of Cambridge have now shown these crows can learn to use new types of tools. When confronted with the Aesop's fable paradigm, which requires stones to be dropped into a water-filled tube to bring floating food within reach, the crows quickly learned to use stones as tools. They then preferred to drop into the tube large rocks rather than small rocks, and heavy objects over light objects (which floated on the surface of the water and so were ineffective).

Further experiments showed that the crows' performances were not based on simple learning, which suggests that the crows had some understanding of how the task actually worked. The authors, therefore, concluded that these crows have cognitive mechanisms beyond simple associative learning that are capable of processing causal information about novel tool types.


For more insight into the intelligence of crows, watch A Murder of Crows (~50 min.) at pbs.org.

The ability to trust, love, and resolve conflict with loved ones starts in childhood—way earlier than you may think. That is one message of a new review of the literature in Current Directions in Psychological Science, a journal published by the Association for Psychological Science. "Your interpersonal experiences with your mother during the first 12 to 18 months of life predict your behavior in romantic relationships 20 years later," says psychologist Jeffry A. Simpson, the author, with University of Minnesota colleagues W. Andrew Collins and Jessica E. Salvatore. "Before you can remember, before you have language to describe it, and in ways you aren't aware of, implicit attitudes get encoded into the mind," about how you'll be treated or how worthy you are of love and affection.

While those attitudes can change with new relationships, introspection, and therapy, in times of stress old patterns often reassert themselves. The mistreated infant becomes the defensive arguer; the baby whose mom was attentive and supportive works through problems, secure in the goodwill of the other person. This is an "organizational" view of human social development. Explains Simpson: "People find a coherent, adaptive way, as best as they can, to respond to their current environments based on what's happened to them in the past." What happens to you as a baby affects the adult you become: It's not such a new idea for psychology—but solid evidence for it has been lacking.

Simpson, Collins, and Salvatore have been providing that evidence: investigating the links between mother-infant relationships and later love partnerships as part of the Minnesota Longitudinal Study of Risk and Adaptation. Their subjects are 75 children of low-income mothers whom they've been assessing from birth into their early 30s, including their close friends and romantic partners. When the children were infants, they were put into strange or stressful situations with their mothers to test how securely the pairs were bonded. Since then, the children—who are now adults—have returned regularly for assessments of their emotional and social development. The authors have focused on their skills and resilience in working through conflicts with school peers, teenage best friends, and finally, love partners.

Through multiple analyses, the research has yielded evidence of that early encoding—confirming earlier psychological theories. But their findings depart from their predecessors' ideas, too. "Psychologists started off thinking there was a lot of continuity in a person's traits and behavior over time," says Simpson. "We find a weak but important thread" between the infant in the mother's arms and the 20-year-old in his lover's. But "one thing has struck us over the years: It's often harder to find evidence for stable continuity than for change on many measures."

The good news: "If you can figure out what those old models are and verbalize them," and if you get involved with a committed, trustworthy partner, says Simpson, "you may be able to revise your models and calibrate your behavior differently." Old patterns can be overcome. A betrayed baby can become loyal. An unloved infant can learn to love.

Rats free trapped companions, even when given choice of chocolate instead

The first evidence of empathy-driven helping behavior in rodents has been observed in laboratory rats that repeatedly free companions from a restraint, according to a new study by University of Chicago neuroscientists. The observation, published in Science, places the origin of pro-social helping behavior earlier in the evolutionary tree than previously thought. Though empathetic behavior has been observed anecdotally in non-human primates and other wild species, the concept had not previously been observed in rodents in a laboratory setting. "This is the first evidence of helping behavior triggered by empathy in rats," said Jean Decety, PhD, Irving B. Harris Professor of Psychology and Psychiatry at the University of Chicago. "There are a lot of ideas in the literature showing that empathy is not unique to humans, and it has been well demonstrated in apes, but in rodents it was not very clear. We put together in one series of experiments evidence of helping behavior based on empathy in rodents, and that's really the first time it's been seen."

The study demonstrates the deep evolutionary roots of empathy-driven behavior, said Jeffrey Mogil, the E.P. Taylor Professor in Pain Studies at McGill University, who has studied emotional contagion of pain in mice. "On its face, this is more than empathy, this is pro-social behavior," said Mogil, who was not involved in the study. "It's more than has been shown before by a long shot, and that's very impressive, especially since there's no advanced technology here."

The experiments, designed by psychology graduate student and first author Inbal Ben-Ami Bartal with co-authors Decety and Peggy Mason, placed two rats that normally share a cage into a special test arena. One rat was held in a restrainer device — a closed tube with a door that can be nudged open from the outside. The second rat roamed free in the cage around the restrainer, able to see and hear the trapped cagemate but not required to take action. The researchers observed that the free rat acted more agitated when its cagemate was restrained, compared to its activity when the rat was placed in a cage with an empty restrainer. This response offered evidence of an "emotional contagion," a frequently observed phenomenon in humans and animals in which a subject shares in the fear, distress or even pain suffered by another subject.

While emotional contagion is the simplest form of empathy, the rats' subsequent actions clearly comprised active helping behavior, a far more complex expression of empathy. After several daily restraint sessions, the free rat learned how to open the restrainer door and free its cagemate. Though slow to act at first, once the rat discovered the ability to free its companion, it would take action almost immediately upon placement in the test arena. "We are not training these rats in any way," Bartal said. "These rats are learning because they are motivated by something internal. We're not showing them how to open the door, they don't get any previous exposure on opening the door, and it's hard to open the door. But they keep trying and trying, and it eventually works."

To control for motivations other than empathy that would lead the rat to free its companion, the researchers conducted further experiments. When a stuffed toy rat was placed in the restrainer, the free rat did not open the door. When opening the restrainer door released his companion into a separate compartment, the free rat continued to nudge open the door, ruling out the reward of social interaction as motivation. The experiments left behavior motivated by empathy as the simplest explanation for the rats' behavior. "There was no other reason to take this action, except to terminate the distress of the trapped rats," Bartal said. "In the rat model world, seeing the same behavior repeated over and over basically means that this action is rewarding to the rat."

As a test of the power of this reward, another experiment was designed to give the free rats a choice: free their companion or feast on chocolate. Two restrainers were placed in the cage with the rat, one containing the cagemate, another containing a pile of chocolate chips. Though the free rat had the option of eating all the chocolate before freeing its companion, the rat was equally likely to open the restrainer containing the cagemate before opening the chocolate container. "That was very compelling," said Mason, PhD, Professor of Neurobiology. "It said to us that essentially helping their cagemate is on a par with chocolate. He can hog the entire chocolate stash if he wanted to, and he does not. We were shocked."

Now that this model of empathic behavior has been established, the researchers are carrying out additional experiments. Because not every rat learned to open the door and free its companion, studies can compare these individuals to look for the biological source of these behavioral differences. Early results suggested that females were more likely to become door openers than males, perhaps reflecting the important role of empathy in motherhood and providing another avenue for study. "This model of empathy and helping behavior opens the path for elucidating aspects of the underlying neurophysiological mechanisms that were not accessible until now." Bartal said.

The experiments also provide further evidence that empathy-driven helping behavior is not unique to humans – and suggest that Homo sapiens could learn a lesson from its rat cousins. "When we act without empathy we are acting against our biological inheritance," Mason said. "If humans would listen and act on their biological inheritance more often, we'd be better off."

A father in Louisiana bludgeoned and beheaded his disabled 7-year-old son last August because he no longer wanted to care for the boy. For most people, such a heinous act is unconscionable. But it may be that a person can become callous enough to commit human atrocities because of a failure in the part of the brain that's critical for social interaction. A new study by researchers at Duke University and Princeton University suggests this function may disengage when people encounter others they consider disgusting, thus "dehumanizing" their victims by failing to acknowledge they have thoughts and feelings.

This shortcoming also may help explain how propaganda depicting Tutsi in Rwanda as cockroaches and Hitler's classification of Jews in Nazi Germany as vermin contributed to torture and genocide, the study said. "When we encounter a person, we usually infer something about their minds. Sometimes, we fail to do this, opening up the possibility that we do not perceive the person as fully human," said lead author Lasana Harris, an assistant professor in Duke University's Department of Psychology & Neuroscience and Center for Cognitive Neuroscience. Harris co-authored the study with Susan Fiske, a professor of psychology at Princeton University.

Social neuroscience has shown through MRI studies that people normally activate a network in the brain related to social cognition -- thoughts, feelings, empathy, for example -- when viewing pictures of others or thinking about their thoughts. But when participants in this study were asked to consider images of people they considered drug addicts, homeless people, and others they deemed low on the social ladder, parts of this network failed to engage. What's especially striking, the researchers said, is that people will easily ascribe social cognition -- a belief in an internal life such as emotions -- to animals and cars, but will avoid making eye contact with the homeless panhandler in the subway. "We need to think about other people's experience," Fiske said. "It's what makes them fully human to us."

The duo's previous research suggested that a lack of social cognition can be linked to not acknowledging the mind of other people when imagining a day in their life, and rating them differently on traits that we think differentiate humans from everything else. This latest study expands on that earlier work to show that these traits correlate with activation in brain regions beyond the social cognition network. These areas include those brain areas involved in disgust, attention and cognitive control. The result is what the researchers call "dehumanized perception," or failing to consider someone else's mind. Such a lack of empathy toward others can also help explain why some members of society are sometimes dehumanized, they said.

For this latest study, 119 undergraduates from Princeton completed judgment and decision-making surveys as they viewed images of people. The researchers sought to examine the students' responses to common emotions triggered by images such as:

• a female college student and male American firefighter (pride)
• a business woman and rich man (envy)
• an elderly man and disabled woman (pity)
• a female homeless person and male drug addict (disgust)

After imagining a day in the life of the people in the images, participants next rated the same person on various dimensions. They rated characteristics including the warmth, competence, similarity, familiarity, responsibility of the person for his/her situation, control of the person over their situation, intelligence, complex emotionality, self-awareness, ups-and-downs in life, and typical humanity. Participants then went into the MRI scanner and simply looked at pictures of people.

The study found that the neural network involved in social interaction failed to respond to images of drug addicts, the homeless, immigrants and poor people, replicating earlier results. "These results suggest multiple roots to dehumanization," Harris said. "This suggests that dehumanization is a complex phenomenon, and future research is necessary to more accurately specify this complexity."

The sample's mean age was 20, with 62 female participants. The ethnic composition of the Princeton students who participated in the study was 68 white, 19 Asian, 12 of mixed descent, and 6 black, with the remainder not reporting.

When children have been exposed to family violence, their brains become increasingly "tuned" for processing possible sources of threat, a new study reports. The findings, reported in the December 6th issue of Current Biology, a Cell Press publication, reveal the same pattern of brain activity in these children as seen previously in soldiers exposed to combat. The study is the first to apply functional brain imaging to explore the impact of physical abuse or domestic violence on the emotional development of children, according to the researchers.

"Enhanced reactivity to a biologically salient threat cue such as anger may represent an adaptive response for these children in the short term, helping keep them out of danger," said Eamon McCrory of University College London. "However, it may also constitute an underlying neurobiological risk factor increasing their vulnerability to later mental health problems, and particularly anxiety." Maltreatment is known to be one of the most potent environmental risk factors associated with anxiety and depression. Still, McCrory said, "relatively little is known how such adversity 'gets under the skin' and increases a child's later vulnerability, even into adulthood."

The new study shows that children with documented exposure to violence in the home differ in their brain response to angry versus sad faces. When presented with angry faces, children with a history of abuse show heightened activity in the brain's anterior insula and amygdala, regions involved in detecting threat and anticipating pain. McCrory says the changes don't reflect damage to the brain. Rather, the patterns represent the brain's way of adapting to a challenging or dangerous environment. Still, those shifts may come at the cost of increased vulnerability to later stress.

Although the results may not have immediate practical implications, they are nonetheless critical given that a significant minority of children are exposed to family violence, McCrory says. "This underlines the importance of taking seriously the impact for a child of living in a family characterized by violence. Even if such a child is not showing overt signs of anxiety or depression, these experiences still appear to have a measurable effect at the neural level."

The witness points out the criminal in a police lineup. She swears she'd remember that face forever. Then DNA evidence shows she's got the wrong guy. It happens so frequently that many courts are looking with extreme skepticism at eyewitness testimony.

Is there a way to get a more accurate reading of memory? A new study says yes. "Eye movements are drawn quickly to remembered objects," says Deborah Hannula, assistant professor at the University of Wisconsin Milwaukee, who conducted the study with Carol L. Baym and Neal J. Cohen of the University of Illinois, Urbana-Champaign and David E. Warren of the University of Iowa College of Medicine. Tracking where and for how long a person focuses his or her eyes "can distinguish previously seen from novel materials even when behavioral reports fail to do so." The findings will appear in an upcoming issue of Psychological Science, a journal published by the Association for Psychological Science.

The researchers gave university students 36 faces to study. These target faces were also morphed to produce images closely resembling them; the morphed phases were not seen during the study phase. The students were then shown 36 three-face displays, one at a time. Told that the studied faces wouldn't always be there, the participants had to press a button indicating which face was the studied one, or simply choose a face if they felt none had been studied. They then reported verbally whether the studied target face was present or not. While they looked at the 3-face display, their eye movements were recorded, tracking where the eyes focused first and what proportion of time was spent looking there. For the analysis, the psychologists divided the faces into three groups: studied targets; morphs mistaken for the "target" face; and morphs chosen and known to be incorrect.

Participants easily identified the target faces most of the time. They also spent more time looking at these faces, and did so soon after the 3-face display had been presented. "The really interesting finding is that before they chose a face and pressed a button, there was disproportionate viewing of the target faces as compared to either type of selected face," said Hannula. However, "after the response was made, viewing tended to mimic the behavioral endorsement of a face as studied or not, whether that endorsement was correct or incorrect." In other words, "pre-response viewing seems to reflect actual experience, and post-response viewing seems to reflect the decision making process and whether or not the face will be endorsed as studied."

Hannula theorizes as to what is happening: "Early disproportionate viewing of the target face may precede and help give rise to awareness that a particular face has been studied. Subsequently, we begin to think about the choice that we're making"—we look closely, compare and weigh the options—"these cognitive processes permit us to make a decision, but may also lead us down the wrong path. In this case, leading us to endorse a face as studied despite having never seen it before." Aside from the potential for practical application, says Hannula, eye movement methods could be used to examine memory in individuals—like some psychiatric patients and children – who may have trouble communicating what it is that they remember. "Eye movements might provide us with more information about what exactly these individuals remember than behavioral reports alone."

Human minds have hit an evolutionary "sweet spot" and - unlike computers - cannot continually get smarter without trade-offs elsewhere, according to research by the University of Warwick. Researchers asked the question why we are not more intelligent than we are given the adaptive evolutionary process. Their conclusions show that you can have too much of a good thing when it comes to mental performance. The evidence suggests that for every gain in cognitive functions, for example better memory, increased attention or improved intelligence, there is a price to pay elsewhere - meaning a highly-evolved "supermind" is the stuff of science fiction.

University of Warwick psychology researcher Thomas Hills and Ralph Hertwig of the University of Basel looked at a range of studies, including research into the use of drugs like Ritalan which help with attention, studies of people with autism as well as a study of the Ashkenazi Jewish population. For instance, among individuals with enhanced cognitive abilities- such as savants, people with photographic memories, and even genetically segregated populations of individuals with above average IQ, these individuals often suffer from related disorders, such as autism, debilitating synaesthesia and neural disorders linked with enhanced brain growth.

Similarly, drugs like Ritalan only help people with lower attention spans whereas people who don't have trouble focusing can actually perform worse when they take attention-enhancing drugs. Dr Hills said: "These kinds of studies suggest there is an upper limit to how much people can or should improve their mental functions like attention, memory or intelligence. Take a complex task like driving, where the mind needs to be dynamically focused, attending to the right things such as the road ahead and other road users – which are changing all the time. If you enhance your ability to focus too much, and end up over-focusing on specific details, like the driver trying to hide in your blind spot, then you may fail to see another driver suddenly veering into your lane from the other direction. Or if you drink coffee to make yourself more alert, the trade-off is that it is likely to increase your anxiety levels and lose your fine motor control. There are always trade-offs. In other words, there is a 'sweet spot' in terms of enhancing our mental abilities – if you go beyond that spot - just like in the fairy-tales - you have to pay the price."

States that prescribe abstinence-only sex education programs in public schools have significantly higher teenage pregnancy and birth rates than states with more comprehensive sex education programs, researchers from the University of Georgia have determined. The researchers looked at teen pregnancy and birth data from 48 U.S. states to evaluate the effectiveness of those states' approaches to sex education, as prescribed by local laws and policies. "Our analysis adds to the overwhelming evidence indicating that abstinence-only education does not reduce teen pregnancy rates," said Kathrin Stanger-Hall, assistant professor of plant biology and biological sciences in the Franklin College of Arts and Sciences. Hall is first author on the resulting paper, which has been published online in the journal PLoS ONE.

The study is the first large-scale evidence that the type of sex education provided in public schools has a significant effect on teen pregnancy rates, Hall said. "This clearly shows that prescribed abstinence-only education in public schools does not lead to abstinent behavior," said David Hall, second author and assistant professor of genetics in the Franklin College. "It may even contribute to the high teen pregnancy rates in the U.S. compared to other industrialized countries."

Along with teen pregnancy rates and sex education methods, Hall and Stanger-Hall looked at the influence of socioeconomic status, education level, access to Medicaid waivers and ethnicity of each state's teen population. Even when accounting for these factors, which could potentially impact teen pregnancy rates, the significant relationship between sex education methods and teen pregnancy remained: the more strongly abstinence education is emphasized in state laws and policies, the higher the average teenage pregnancy and birth rates. "Because correlation does not imply causation, our analysis cannot demonstrate that emphasizing abstinence causes increased teen pregnancy. However, if abstinence education reduced teen pregnancy as proponents claim, the correlation would be in the opposite direction," said Stanger-Hall.

The paper indicates that states with the lowest teen pregnancy rates were those that prescribed comprehensive sex and/or HIV education, covering abstinence alongside proper contraception and condom use. States whose laws stressed the teaching of abstinence until marriage were significantly less successful in preventing teen pregnancies. These results come at an important time for legislators. A new evidence-based Teen Pregnancy Prevention Initiative was signed into federal law in December 2009 and awarded $114 million for implementation. However, federal abstinence-only funding was renewed for 2010 and beyond by including $250 million of mandatory abstinence-only funding as part of an amendment to the Senate Finance Committee's health-reform legislation. With two types of federal funding programs available, legislators of individual states now have the opportunity to decide which type of sex education -- and which funding option -- to choose for their state and possibly reconsider their state's sex education policies for public schools, while pursuing the ultimate goal of reducing teen pregnancy rates.

Stanger-Hall and Hall conducted this large-scale analysis to provide scientific evidence to inform this decision. "Advocates for continued abstinence-only education need to ask themselves: If teens don't learn about human reproduction, including safe sexual health practices to prevent unintended pregnancies and sexually transmitted diseases, as well as how to plan their reproductive adult life in school, then when should they learn it and from whom?" said Stanger-Hall.

Amphetamine use in adolescence can cause neurobiological imbalances and increase risk-taking behavior, and these effects can persist into adulthood, even when subjects are drug free. These are the conclusions of a new study using animal models conducted by McGill University Health Centre (MUHC) researcher Dr. Gabriella Gobbi and her colleagues. The study, published in The International Journal of Neuropsychopharmacology, is one of the first to shed light on how long-term amphetamine use in adolescence affects brain chemistry and behavior. "We looked at the effects of long-term amphetamine use on important neurotransmitters and on risk-taking behavior in adolescent rats," says Dr. Gobbi, a researcher in Mental Illness and Addiction from the Research Institute of the MUHC and associate professor at the Faculty of Medicine at McGill University. "The brain chemistry of these rodents is very similar to that of humans, so this model provided us with very useful insights into amphetamine use in a human population."

Amphetamine is a psychostimulant drug which produces increased wakefulness and focus, in association with decreased fatigue and appetite. This drug, commonly known as "speed", is also used recreationally and as a performance enhancer. According to the United Nations Office on Drugs and Crime (UNODOC) report (2011), more than 10 per cent of adolescents in the U.S. have used amphetamines. In Europe, between two and seven per cent of adolescents have tried amphetamines, and in Canada the number is estimated at just over five per cent.

Study subjects were given one of three dosing regimens of amphetamine during adolescence. When they reached adulthood, drugs were withdrawn and their neurophysiological activity and risk-taking behavior were studied. "We focused on the key neurotransmitters serotonin, dopamine and norepinephrine," Dr. Gobbi explains. "We found abnormalities in brain activity associated with all three of these neurochemicals, called "monoamines". Imbalances of monoamines are associated with emotional disturbances and mental diseases such as depression or addiction." Researchers also noted behavioral changes in all dosing groups. Hyperactivity was observed in rodents exposed to a moderate dose of amphetamine during adolescence, while risk-taking behavior increased in every dosage group. "Obviously we have to be very cautious about applying these results to a human population," says Dr. Gobbi. "However, given the basic similarities between human and rodent brains, these results are cause for concern. They suggest that the effects of amphetamine use can persist into adulthood, even if the subject is no longer taking drugs, and that these effects include a tendency toward risk-taking behavior."

A cognitive map enables orientation

The cerebellum is far more intensively involved in helping us navigate than previously thought. To move and learn effectively in spatial environments our brain, and particularly our hippocampus, creates a "cognitive" map of the environment. The cerebellum contributes to the creation of this map through altering the chemical communication between its neurones. If this ability is inactivated, the brain is no longer able to to create an effective spatial representation and thus navigation in an environment becomes impaired. The details of these observations were recently published in Science by the Ruhr University neuroscientist, Marion André who is a student of the International Graduate School of Neuroscience( IGSN), along with her colleagues in France.

A cognitive map in the hippocampus
In order to navigate efficiently in an environment, we need to create and maintain a reliable internal representation of the external world. A key region enabling such representation is the hippocampus which contains specialized pyramidal neurons named place cells. Each place cell is activated at specific location of the environment and gives dynamic information about self-location relative to the external world. These neurons thus generate a cognitive map in the hippocampal system through the integration of multi sensory inputs combining external information (such as visual, auditory, olfactory and tactile cues) and inputs generated by self-motion (i.e. optic flow, proprioceptive and vestibular information).

Decisive: synaptic plasticity
Our ability to navigate also relies on the potential to use this cognitive map to form an optimal trajectory toward a goal. The cerebellum, a foliate region based at the back of the brain, has been recently shown to participate in the formation of the optimal trajectory. This structure contains neurons that are able to increase or decrease their chemical communication, a mechanism called synaptic plasticity. A decrease in the synaptic transmission of the cerebellar neurons, named long-term depression (LTD) participates in the optimization of the path toward a goal.

No orientation without LTD
Using transgenic mice that had a mutation impairing exclusively LTD of the cerebellar neurons, the neuroscientists were able to show that the cerebellum participates also in the formation of the hippocampal cognitive map. Indeed mice lacking this form of cerebellar plasticity were unable to build a reliable cognitive representation of the environment when they had to use self-motion information. Consequently, they were unable to navigate efficiently towards a goal in the absence of external information (for instance in the dark). This work highlights for the first time an unsuspected function of the cerebellum in shaping the representation of our body in space.

Racial minorities pay systemically more for basic water and sewer services than white people, according to a study by Michigan State University researchers. This "structural inequality" is not necessarily a product of racism, argues sociologist Stephen Gasteyer, but rather the result of whites fleeing urban areas and leaving minority residents to bear the costs of maintaining aging water and sewer infrastructure. "This study demonstrates a disturbing racial effect to the cost of basic services," said Gasteyer, assistant professor of sociology. "People of color have the fewest opportunities to leave urban centers and are left to pay for the crumbling legacy of a bygone economic era." The findings by Gasteyer and Rachel Butts will appear in an upcoming issue of the research journal Environmental Practice.

The researchers analyzed Census data on self-reported water and sewer costs in Michigan. The study found that urban residents actually pay more than rural residents, which refutes conventional wisdom, Gasteyer said. But perhaps more importantly, Gasteyer said, water and sewer services cost more in areas with greater proportions of racial minorities.

Detroit is the "poster child" for this problem, Gasteyer said. The city has lost more than 60 percent of its population since 1950, and the water and sewer infrastructure is as much as a century old in some areas. Billions of gallons of water are lost through leaks in the aging lines every year, and the entire system has been under federal oversight since 1977 for wastewater violations. "A fair proportion of Detroit's large low-income population cannot afford the burden of rate increases meant to offset infrastructure repairs, leading to tens of thousands of customers getting their water turned off every year," Gasteyer said.

Water and sewer lines are aging throughout the country. According to the U.S. Environmental Protection Agency, hundreds of billions of dollars will be needed to repair deteriorating systems over the next 20 years. Paying for those upgrades likely will be a major issue in shrinking cities such as Cleveland, Pittsburgh, St. Louis, Birmingham, Ala., and many others, Gasteyer said. "Everything is wearing out, and we are going to have to grapple with how we pay for these so-called liquid assets that need to be upgraded," Gasteyer said. "At the same time, we need to be cognizant of who may be paying an unsustainable burden as those rates go up."

Middle-class children ask their teachers for help more often and more assertively than working-class children and, in doing so, receive more support and assistance from teachers according to a study from the University of Pennsylvania. The findings are reported in the December issue of the American Sociological Review in a paper entitled, "'I Need Help!' Social Class and Children's Help-Seeking in Elementary School" by Jessica McCrory Calarco, a Ph.D. candidate in Sociology in Penn's School of Arts and Sciences. The paper is based on Calarco's dissertation research, a longitudinal ethnographic study of students in one socioeconomically diverse, public elementary school.

For three years, she followed a cohort of students as they progressed from third through fifth grade, observing them regularly in school and interviewing teachers, parents, and students to show that children's social-class backgrounds shaped when and how they sought help in the classroom. "We know that middle-class parents are better able than working-class parents to secure advantages for themselves and their children, but not when and where they learned to do so, or whether they teach their children to do the same," Calarco said. "My research answers those questions by looking at children's role in stratification—how they try to secure their own advantages in the classroom."

Her study showed that middle-class children regularly approached teachers with questions and requests and were much more proactive and assertive in asking for help. Rather than wait for assistance, the middle-class children called out or approached teachers directly, even interrupting to make requests. Working-class children, on the other hand, rarely asked for help from teachers, doing so only as a last resort. Furthermore, when working-class children did ask for help, they tended to do so in less obvious ways (e.g., hanging back or sitting with their hand raised), meaning that they often waited longer for teachers to notice and respond. "Teachers want kids to ask for help if they are struggling, but they rarely make those expectations explicit. That leaves kids to figure out when and how to ask for help," Calarco explained.

In another related project, Calarco found that children learn whether and how to ask for help at school, in part, through the training that they receive from their parents at home. She noted that, "unlike their working-class counterparts, middle-class parents explicitly encourage children to feel comfortable asking for help from teachers, and also deliberately coach children on the language and strategies to use in making these requests." As a result, middle-class children came to school better equipped to secure the support that they needed to complete their assignments quickly and correctly, and also appeared more engaged in the learning process.

Calarco said that while teachers don't mean to privilege some children over others, they tend to be more responsive to middle-class children's help-seeking styles, giving those who ask for help more attention and support in the classroom, and also seeing them as more "proactive" learners. "What that means is that middle-class kids' help-seeking skills and strategies effectively become a form of 'cultural capital' in the classroom—by activating those resources, middle-class kids can secure their own advantages in the classroom," she explained. "It also means that children play a more active role in stratification than previous research has recognized."

The ASR study concludes that inequalities in education are not just the product of differences in the resources that families and schools provide for children; they also reflect differences in the resources that children can secure for themselves in the classroom.

Consumers often attempt to match causes to consequences to make sense of events that unfold in their lives or in the world, but this strategy leads to erroneous conclusions, according to a new study in the Journal of Consumer Research.

"Why did my mobile phone stop working? Why did I get this job? Why did the stock market go down today? People often need to decide which cause, out of a large set of candidate causes, was responsible for an event," write authors Robyn A. LeBoeuf (University of Florida) and Michael I. Norton (Harvard University). "This research shows that people allow arbitrary, unrelated downstream consequences of an event to bias their views of what caused the event in the first place."

The authors conducted a series of experiments in which they presented participants with an event and a consequence. Some participants learned that the event had a large consequence, and others learned that the same event had a small consequence.

For example, participants in one experiment read about a student whose computer crashed, causing him to lose a term paper. In one scenario, the professor did not grant the student an extension. The student failed the course, did not graduate, and lost a job offer. Other participants read that the professor granted an extension, which allowed the student to graduate and get the job. When it came to deciding whether the computer crash had a large cause (a widespread virus) or a small cause (a malfunctioning cooling fan), the participants who read about the student losing his job were more likely to select the "large cause." And they had a more negative attitude toward the student's anti-virus software. "These effects arose even though the crash itself was identical in both cases and the consequences were uninformative about the causes," the authors write. The authors found similar results when participants matched causes to consequences in geopolitical and public health issues.

"Life in general, and decision-making in particular, is often fraught with uncertainty; matching causes to consequences may be just one small way in which people manage the largely uncertain world they navigate," the authors conclude.

If you tell yourself that someone who's being mean is just having a bad day—it's not about you—you may actually be able to stave off bad feelings, according to a new study which will be published in an upcoming issue of Psychological Science, a journal of the Association for Psychological Science.

Having someone angry at you isn't pleasant. A strategy commonly suggested in cognitive-behavioral psychotherapy is to find another way to look at the angry person. For example, you might tell yourself that they've probably just lost their dog or gotten a cancer diagnosis and are taking it out on you. Stanford researchers Jens Blechert, Gal Sheppes, Carolina Di Tella, Hants Williams, and James J. Gross wanted to study the efficiency and the speed of the process of reappraising emotions. "You can see this as a kind of race between the emotional information and the reappraisal information in the brain: emotional processing proceeds from the back to the front of the brain, and the reappraisal is generated in the front of the brain and proceeds toward the back of the brain where it modifies emotional processing" Blechert says.

Blechert and his colleagues came up with two experiments to study this process. Participants were shown several series of faces and tested on their reactions. For example, in one set, they were told to consider that the people they'd seen had had a bad day, but it's nothing to do you with you. "So we trained the participants a little bit, not to take this emotion personally, but directed at someone else," Blechert says.

They found that, once people had adjusted their attitude toward someone, they weren't disturbed by that person's angry face the next time it appeared. On the other hand, when participants were told to just feel the emotions brought on by an angry face, they continued to be upset by that face. In a second study, the researchers recorded electrical brain activity from the scalp and found that reappraising wiped out the signals of the negative emotions people felt when they just looked at the faces.

Psychologists used to think that people had to feel the negative emotion, and then get rid of it; this research suggests that, if people are prepared, it's actually a much faster and deeper process. "If you're trained with reappraisal, and you know your boss is frequently in a bad mood, you can prepare yourself to go into a meeting," says Blechert, who also works as a therapist. "He can scream and yell and shout but there'll be nothing." But this study only looked at still pictures of angry faces; next, Blechert would like to test how people respond to a video of someone yelling at them.

With record levels of student stress reported in a recent UCLA survey, can a simple stress-reducing meditation technique be a viable solution?

A new study published in the Journal of Instructional Psychology found the Transcendental Meditation (TM) technique significantly decreased psychological distress in public school students. The study, conducted with at-risk minority secondary school students, showed a 36 percent reduction in overall psychological distress. Significant decreases were also found in trait anxiety and depressive symptoms.

Rising Stress Levels Affect Emotional and Physical Health
The percentage of students in the UCLA survey reporting good or above-average high school emotional health dropped from 55.3 percent in 2009 to 51.9 percent in 2010. This marks the lowest level within the past 25 years. Dr. Charles Elder, MD, lead author of the TM study, and investigator at Kaiser Permanente Center for Health Research, emphasized the important implications of the findings on reduced stress. "It is vital that we start addressing the high levels of emotional stress being reported by high school and college students. Decreased stress can have a positive impact on mental health, and can also reduce the risk for hypertension, obesity, and diabetes—major risk factors for heart disease," explained Dr. Elder. Educational research has also linked student stress to negative school behavior and poor academic performance.

Promising Findings for Education
"These new findings on reduced stress, along with the recent research on academic achievement gains, hold tremendous promise for public education," said Sanford Nidich, EdD, principal investigator, and professor of education at Maharishi University of Management. "There is a growing body of evidence showing Transcendental Meditation to be an easy to implement, value-added educational program that promotes emotional health and increases academic achievement in at-risk students," said Dr. Nidich.

A total of 106 secondary school students, 87% racial and ethnic minorities, took part in the study. Results showed that over a four-month period, students practicing Transcendental Meditation as part of their schools' Quiet Time program exhibited significant reductions in psychological distress factors compared to controls.

According to James Dierke, 2008 National Association of Secondary School Principals—National Middle School Principal of the Year, "Stress is the number one enemy of public education, especially in inner-city schools. It creates tension, violence, and compromises the cognitive and psychological capacity of students to learn and grow. The TM/Quiet Time program is the most powerful, effective program I have come across in my 39 years as a public school educator for addressing this problem. It is nourishing children and providing them an immensely valuable tool for life. It is saving lives." 

The witness points out the criminal in a police lineup. She swears she'd remember that face forever. Then DNA evidence shows she's got the wrong guy. It happens so frequently that many courts are looking with extreme skepticism at eyewitness testimony.

Is there a way to get a more accurate reading of memory? A new study says yes. "Eye movements are drawn quickly to remembered objects," says Deborah Hannula, assistant professor at the University of Wisconsin Milwaukee, who conducted the study with Carol L. Baym and Neal J. Cohen of the University of Illinois, Urbana-Champaign and David E. Warren of the University of Iowa College of Medicine. Tracking where and for how long a person focuses his or her eyes "can distinguish previously seen from novel materials even when behavioral reports fail to do so." The findings will appear in an upcoming issue of Psychological Science, a journal published by the Association for Psychological Science.

The researchers gave university students 36 faces to study. These target faces were also morphed to produce images closely resembling them; the morphed phases were not seen during the study phase. The students were then shown 36 three-face displays, one at a time. Told that the studied faces wouldn't always be there, the participants had to press a button indicating which face was the studied one, or simply choose a face if they felt none had been studied. They then reported verbally whether the studied target face was present or not. While they looked at the 3-face display, their eye movements were recorded, tracking where the eyes focused first and what proportion of time was spent looking there. For the analysis, the psychologists divided the faces into three groups: studied targets; morphs mistaken for the "target" face; and morphs chosen and known to be incorrect.

Participants easily identified the target faces most of the time. They also spent more time looking at these faces, and did so soon after the 3-face display had been presented. "The really interesting finding is that before they chose a face and pressed a button, there was disproportionate viewing of the target faces as compared to either type of selected face," said Hannula. However, "after the response was made, viewing tended to mimic the behavioral endorsement of a face as studied or not, whether that endorsement was correct or incorrect." In other words, "pre-response viewing seems to reflect actual experience, and post-response viewing seems to reflect the decision making process and whether or not the face will be endorsed as studied."

Hannula theorizes as to what is happening: "Early disproportionate viewing of the target face may precede and help give rise to awareness that a particular face has been studied. Subsequently, we begin to think about the choice that we're making"—we look closely, compare and weigh the options—"these cognitive processes permit us to make a decision, but may also lead us down the wrong path. In this case, leading us to endorse a face as studied despite having never seen it before." Aside from the potential for practical application, says Hannula, eye movement methods could be used to examine memory in individuals—like some psychiatric patients and children – who may have trouble communicating what it is that they remember. "Eye movements might provide us with more information about what exactly these individuals remember than behavioral reports alone."