The relationship between the size of a brain structure and the ability to recover from traumatic experiences also may influence overall personality type, according to a study from Massachusetts General Hospital (MGH) researchers. In a followup to earlier findings that an area of the brain called the medial orbitofrontal cortex (mOFC) appears thicker in those who can better control their emotional response to unpleasant memories, the investigators found that study participants who exhibited better fear inhibition also score higher in measures of extraversion – an energetic, outgoing personality. The report appears in the Nov. 28 issue of NeuroReport.

"Some studies have demonstrated links between extraversion or the trait of neuroticism and the overall activity of brain regions that include the mOFC. But this is the first time anyone has looked at the potential relation of both brain structure and fear extinction to personality traits," says Mohammed Milad, PhD, of the MGH Department of Psychiatry, a co-lead author of the study.

Most individuals initially respond with physical and emotional distress to situations that bring back memories of traumatic events, but such responses usually diminish over time, as the situations are repeated without unpleasant occurrences. The ability to suppress those negative responses is called "extinction memory," and its deficiency may lead to anxiety disorders such as post-traumatic stress disorder. In their previous study, the MGH team focused on the ventromedial prefrontal cortex – an area on the lower surface of the brain that includes the mOFC and is believed to inhibit the activity of the amygdala, a structure known to be involved with fear. The current report combined the data analyzed in that study – published in the July 26, 2005, Proceedings of the National Academy of Science – with the results from a standard personality test. Since earlier research has associated levels of extraversion and neuroticism – oversensitivity and emotional instability – with vulnerability to anxiety disorders, the current experiment focused on those traits.

As described in the PNAS study, over two days 14 study participants viewed a series of digital photos that featured lamps with either a red or a blue light shining. On the first day, participants viewed the photos several times with a mild electric shock – described as annoying but not painful – delivered to their hands after one, but not the other, colored light appeared. They then viewed the photos again with no shocks administered. On the second day, participants' anxiety levels, determined by perspiration on the palm of the hand, were measured while they once again viewed the photos with both colors displayed but no shocks given. Structural magnetic resonance (MR) images of the volunteers' brains showed that those who responded with less anxiety on the second day also had a thicker mOFC, and no other areas of the brain appeared to be correlated with extinction retention.

Combining the results of the personality tests with the previously reported data revealed that both improved extinction retention and a thicker mOFC were associated with higher levels of extraversion and lower neuroticism. Using a statistical tool that analyzes whether one specific factor influences the relationship between the two other factors, the researchers found that while the relation between mOFC thickness and increased extraversion is mediated by extinction retention, the association between mOFC thickness and extinction retention does not seem to directly affect neuroticism.

"This study illustrates how measurement of a brain structure can be linked to a complex character trait like extraversion through a simpler behavioral measure like extinction retention," says Scott Rauch, MD, director of the Psychiatric Neuroscience Research Division in MGH Psychiatry and co-lead author of the paper. "Understanding how personality is based in the brain is important both for insights into personality disorders and for conditions in which personality may confer vulnerability, such as anxiety disorders."

Rauch adds, "We are in the process of studying the link between extinction retention and regional brain function and hope to investigate how developmental factors may govern the structure and function of the mOFC. The ability to modify mOFC activity may eventually prove to be of therapeutic value." Rauch is an associate professor of Psychiatry at Harvard Medical School.

EurekAlert
28 November 2005

Researchers from the University of Cincinnati have found that eating or drinking sweets may decrease the production of the stress-related hormone glucocorticoid—which has been linked to obesity and decreased immune response.

“Glucocorticoids are produced when psychological or physical stressors activate a part of the brain called the ‘stress axis,’” said Yvonne Ulrich-Lai, PhD, a postdoctoral fellow in the department of psychiatry. “These hormones help an individual survive and recover from stress, but have been linked to increased abdominal obesity and decreased immune function when produced in large amounts.

“Finding another way to affect the body’s response to stress and limit glucocorticoid production could alleviate some of these dangerous health effects.”

The laboratory findings were presented during a poster session Tuesday, Nov. 15, at the annual Society for Neuroscience meeting in Washington, D.C.

Dr. Ulrich-Lai and a team of researchers from the department of psychiatry showed that when laboratory rats chose to eat or drink sweet snacks their bodies produced lower levels of glucocorticoid.

She said that sweets—especially those made from sugar, not artificial sweetener—might do the trick.

"The sweets we are talking about are not the low-calorie, sugar-substitute variety,” said Dr. Ulrich-Lai. “We actually found that sugar snacks, not artificially sweetened snacks, are better ‘self-medications’ for the two most common types of stress—psychological and physical.”

Psychological stress could involve things such as public speaking, being threatened, or coping with the death of a loved one. Examples of physical stress are injury, illness, or prolonged exposure to cold.

During the study, researchers gave adult male rats free access to food and water and also offered them a small amount of sugar drink, artificially sweetened drink, or water twice a day. After two weeks, the rats were given a physical and psychological stress challenge. Following both types of stress, rats that had consumed the sugar drink had lower glucocorticoid levels than those that drank the water. Those drinking the artificially sweetened drink showed only slightly reduced glucocorticoid levels.

Dr. Ulrich-Lai noted that although her team was not studying the health effects of the sweetened drinks, they did not notice a body-weight increase in the rats consuming the sugar drinks.

James Herman, PhD, co-author, professor and stress neurobiologist in the department of psychiatry, said the next step will be to determine how these sweetened drinks are decreasing glucocorticoid production.

“We need to find out if there are certain parts of the brain that control the response to stress, then determine if the function of these brain regions are changed by sugar snacking,” he said.

Co-authors also included Dennis Choi and Michelle Ostrander, PhD, both of UC’s psychiatry department.

University of Cincinnati Medical Center News
15 November 2005

BOSTON - November 11, 2005 - The regular practice of meditation appears to produce structural changes in areas of the brain associated with attention and sensory processing. An imaging study led by Massachusetts General Hospital (MGH) researchers showed that particular areas of the cerebral cortex, the outer layer of the brain, were thicker in participants who were experienced practitioners of a type of meditation commonly practiced in the U.S. and other Western countries. The article appears in the Nov. 15 issue of NeuroReport, and the research also is being presented Nov. 14 at the Society for Neuroscience meeting in Washington, DC.

"Our results suggest that meditation can produce experience-based structural alterations in the brain," says Sara Lazar, PhD, of the MGH Psychiatric Neuroimaging Research Program, the study's lead author. "We also found evidence that mediation may slow down the aging-related atrophy of certain areas of the brain."

Studies have shown that mediation can produce alterations in brain activity, and meditation practitioners have described changes in mental function that last long after actual meditation ceases, implying long-term effects. However, those studies usually examined Buddhist monks who practiced mediation as a central focus of their lives.

To investigate whether meditation as typically practiced in the U.S. could change the brain's structure, the current study enrolled 20 practitioners of Buddhist Insight meditation - which focuses on "mindfulness," a specific, nonjudgmental awareness of sensations, feelings and state of mind. They averaged nine years of mediation experience and practiced about six hours per week. For comparison, 15 people with no experience of meditation or yoga were enrolled as controls.

Using standard MRI to produce detailed images of the structure of participants' brains, the researchers found that regions involved in the mental activities that characterize Insight meditation were thicker in the meditators than in the controls, the first evidence that alterations in brain structure may be associated with meditation. They also found that, in an area associated with the integration of emotional and cognitive processes, differences in cortical thickness were more pronounced in older participants, suggesting that meditation could reduce the thinning of the cortex that typically occurs with aging.

"The area where we see these differences is involved in both the modulation of functions like heart rate and breathing and also the integration of emotion with thought and reward-based decision making - a central switchboard of the brain," says Lazar. An instructor in Psychology at Harvard Medical School, she also stresses that the results of such a small study need to be validated by larger, longer-term studies.

Massachusetts General Hospital News Release
11 November 2005

When someone in our social group makes friends with someone from another background, the chances are that our own prejudices will break down, according to new ESRC-funded research.

A study led by Dr. Adam Rutland, of the University of Kent, backs claims that the more we learn about others, the better we are likely to get on with them.

It found that what is termed the 'extended contact' approach, could effectively change children's attitudes and intended behaviour towards refugees, across the entire age range from six to 11.

Extended contact works on the idea that when a member of one group has a close relationship or contact with someone from another, this can lead to more positive attitudes all round.

Best results of all came when children were encouraged to see their own and other groups as sharing a common identity – their school – in addition to retaining their separate one as, say, English or a refugee. In other words, having a 'dual' identity.

To test this theory, researchers presented English children with one of their group who had made friends with a refugee youngster. Exercises over several weeks also included getting children to read adventure stories in which both English and refugee youngsters were shown in a positive light, and as friends.

Dr Rutland said: "Our findings testify to the value of extended contact as an approach to reducing prejudice. In particular, we found that including characters from other backgrounds in the stories read at school was very effective." The project examined various theories about childhood prejudice, and the effectiveness of various processes, or interventions, used by those trying to encourage friendship and co-operation.

The area studied was East Kent, which includes Dover and Folkestone, and contains a high proportion of immigrants or refugees as the main port of entry into the UK. Tension has arisen between the majority community and immigrants. One intervention technique examined - multiple classification skills training - is based on the belief that children are prejudiced because they cannot cope with more than one concept – for instance, that someone is Afro-Caribbean British and friendly. Nor, it is thought, can they take into account other people's points of view.

However, researchers found that though this sort of training improved children's ability to handle multiple concepts, it had no effect on attitudes towards others. Alternative approaches, all found effective, derive from theories that, under a given set of conditions, contact between members of different groups reduces existing prejudices.

Dr Rutland said: "It seems that extended contact leads children to 'include the other in the self' and this in turn leads to more positive attitudes."

EurekAlert
10 November 2005

CHICAGO – Bullying by elementary school children was associated with increased odds of lacking a feeling of safety while at school, having lower academic achievement, and feeling sad most days, according to an article in the November issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.

According to background information in the article, "Bullying is defined as any repeated negative activity or aggression intended to harm or bother someone who is perceived by peers as being less physically or psychologically powerful than the aggressor(s)." In a 2000 survey of more than 15,000 U.S. students, researchers found the prevalence of bullying involvement among teens and preteens was approximately 30 percent. Concerns about the role of bullying in school violence, depression, and health concerns have grown over the past decade.

Gwen M. Glew, M.D., of the University of Washington, Seattle, and colleagues surveyed 3,530 third, fourth, and fifth grade students to determine prevalence of bullying and its association with attendance, academic achievement, suspension or expulsion, and self-reported feelings of sadness, safety and belonging. Students were classified as victims, bullies, bully-victims (those who were both victimized and bullied others), bystanders (children who did not bully others and were not bullied by others) and nonresponders.

Twenty-two percent of the children surveyed reported being involved in bullying, either as a victim, bully, or both. Six percent of the children reported being bullied "always," 14 percent said they bullied others, and two percent said they both bullied and were bullied. All three bullying-involved groups--either as a victim, bully or bully-victim--were significantly more likely than bystanders to feel unsafe at school. Among students who reported feeling as though they did not belong at school, their odds of being a victim were 4.1 times higher than those who felt they belonged at school; their odds of being a bully was 3.1 times higher than those saying they belonged. Bullies and victims were more likely than bystanders to feel sad most days. Both bullies and bully-victims were more likely to be male.

"The prevalence of frequent bullying among elementary school children is substantial. Associations between bullying involvement and school problems indicate this is a serious issue for elementary schools," the authors write. "The take-home message is that elementary school-aged children who are psychologically distressed are more likely to be involved in some form of bullying, and children who struggle academically are more likely to be victims and bully-victims."

EurekAlert
7 November 2005

Men behave in certain ways to retain their partner and to continue their relationship with her. Sometime it's sweet, like holding hands or giving flowers, and sometimes it's a harbinger of danger. A study published in the latest issue of Personal Relationships identifies several specific acts and tactics that lead to the possibility of violence. Vigilance over a partner's whereabouts was the highest-ranking tactic predicting violence across the researchers' three-study investigation. Emotional manipulation, such as a man saying he would "die" if his partner ever left also was predictive of violence. Monopolization of time and the threat to punish for infidelity also were signals of violence. Showing love and care was among the tactics not associated with violence. "Mate retention behaviors are designed to solve several adaptive problems, such as deterring a partner's infidelity and preventing defection from the mating relationship," author Todd K. Shackelford explains.

In the first two studies, the researchers asked independent samples of men and women to report on men's retention behaviors and men's violence against their partners. In the third study, they asked husbands and their wives to report on men's retention behaviors and violence against wives. The highest-ranking correlations between single acts and violence were not consistent across the three studies. But acts such as "dropped by unexpectedly to see what my partner was doing" and "called to make sure my partner was where she said she would be" were the overall third and fifth highest predictors of violence. These acts fall into Vigilance, which the couples reported as the highest–ranking tactic leading to violence and the only tactic across all three studies that uniquely predicts violence. "At a practical level, results of these studies can potentially be used to inform women and men, friends and relatives, of danger signs-- the specific acts and tactics of mate retention that portend the possibility of future violence in relationships in order to prevent it before it has been enacted," the authors conclude.

EurekAlert
27 October 2005

The hippocampus's role in memory may help explain why we cannot remember our early childhood, and why stress affects our memory later in life. [read the article]

APA Monitor
November 2005

Visual information can be processed unconsciously when the area of the brain that records what the eye sees is temporarily shut down, according to research at Rice University in Houston.

The research, published the week of Oct. 31 in the Proceedings of the National Academy of Sciences' (PNAS) online Early Edition, suggests the brain has more than one pathway along which visual information can be sent.

For the study, the researchers induced temporary, reversible blindness lasting only a fraction of a second in nine volunteers with normal vision. Transcranial magnetic stimulation (TMS), a harmless noninvasive technique using brief magnetic pulses, was applied to the volunteers' visual cortex -- the area at the back of the brain that processes what the eye sees - to interrupt the normal visual pathway. The volunteers looked at a computer screen, and during their momentary blindness, either a horizontal or a vertical line or a red or a green dot flashed on the screen.

Researchers then asked the study participants whether they had seen a horizontal or a vertical line; because their primary visual pathway had been shut down, the participants reported that they saw nothing. However, when forced to guess which line had appeared on their computer screen, the participants gave the correct answer 75 percent of the time. When the participants had to guess whether a red or a green dot had flashed on the screen, they gave the correct answer with 81 percent accuracy.

"This high degree of accuracy for both the directional orientation and color tasks was significantly above chance," said Tony Ro, associate professor of psychology and principal investigator for the study. "Even though the human primary visual cortex activity was temporarily shut down, it's clear that detailed visual information was still being processed unconsciously."

Because only a certain region of the thalamus - the area of the brain where all sensory information is relayed -- can process color, the study provides evidence that there must be a pathway that goes through this region of the thalamus to the higher visual centers of the brain, Ro said.

"In addition to providing direct evidence that unconscious processing takes place within the brain - a controversial claim that was advanced by the likes of Sigmund Freud and William James - our results suggest that multiple pathways relay visual input into the central nervous system for different types of processing," Ro said. "And our study also begins to shed light on the brain structures that are necessary for consciousness, with the primary visual cortex playing an essential role for visual awareness."

The phenomenon of "blindsight" has been reported in patients with brain damage who report not seeing something but correctly identify the shape and location when forced to guess. Ro noted that his study demonstrates that TMS can be used successfully to induce blindsight in people with normal vision.

Rice University News Release
31 October 2005