Neuroscience

Articles and news from the latest research reports.

Posts tagged psychology

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Remembering to Forget

June 22nd, 2012

New research suggests that it is possible to suppress emotional autobiographical memories. The study published this month by psychologists at the University of St Andrews reveals that individuals can be trained to forget particular details associated with emotional memories.

The important findings may offer exciting new potential for therapeutic interventions for individuals suffering from emotional disorders, such as depression and post-traumatic stress disorder.

The research showed that although individuals could still accurately recall the cause of the event, they could be trained to forget the consequences and personal meaning associated with the memory.

The work was carried out by researchers Dr Saima Noreen and Professor Malcolm MacLeod of the University’s School of Psychology. Lead author Dr Noreen explained, “The ability to remember and interpret emotional events from our personal past forms the basic foundation of who we are as individuals.

Research is starting to show that autobiographical memories may be forgotten. This image is adapted from a photograph of a painting. Both are in the public domain. The original painting is translated as The Break-Up Letter and was painted by Alfred Émile Léopold Stevens (ca 1867).

“These novel findings show that individuals can be trained to not think about memories that have personal relevance and significance to them and provide the most direct evidence to date that we possess some kind of control over autobiographical memory.”

The research involved participants generating emotional memories in response to generic cue words, such as theatre, barbecue, wildlife etc. Participants were asked to recall the cause of the event, the consequence of the event and the personal meaning they derived from the event.

Subjects were then asked to provide a single word that was personal to them which reminded them of the memory. In a subsequent session, participants were shown the cue and personal word pairings and were asked to either recall the memory associated with the word pair or to not think about the associated memory.

Interestingly, the findings revealed that whilst the entire autobiographical episode was not forgotten, the details associated with the memory were. Specifically, individuals could remember what caused the event, but were able to forget what happened and how it made them feel.

Co-author Professor MacLeod commented, “The capacity to engage in this kind of intentional forgetting may be critical to our ability to maintain coherent images about who we are and what we are like”.

Source: Neuroscience News

Filed under science neuroscience psychology brain memory

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'Trust' hormone oxytocin found at heart of rare genetic disorder

June 22, 2012

The hormone oxytocin - often referred to as the “trust” hormone or “love hormone” for its role in stimulating emotional responses - plays an important role in Williams syndrome (WS), according to a study published June 12, 2012, in PLoS One.

The study, a collaboration between scientists at the Salk Institute for Biological Studies and the University of Utah, found that people with WS flushed with the hormones oxytocin and arginine vasopressin (AVP) when exposed to emotional triggers.

The findings may help in understanding human emotional and behavioral systems and lead to new treatments for devastating illnesses such as WS, post-traumatic stress disorder, anxiety and possibly even autism.

Williams syndrome results from a very clear genetic deletion, allowing us to explore the genetic and neuronal basis of social behavior,” says Ursula Bellugi, the director of Salk’s Laboratory for Cognitive Neuroscience and a co-author on the paper. “This study provides us with crucial information about genes and brain regions involved in the control of oxytocin and vasopressin, hormones that may play important roles in other disorders.”

WS arises from a faulty recombination event during the development of sperm or egg cells. As a result, virtually everyone with WS has exactly the same set of genes missing (25 to 28 genes are missing from one of two copies of chromosome 7). There also are rare cases of individuals who retain one or more genes that most people with the disorder have lost.

To children with WS, people are much more comprehensible than inanimate objects. Despite myriad health problems they are extremely gregarious, irresistibly drawn to strangers, and insist on making eye contact. They have an affinity for music. But they also experience heightened anxiety, have an average IQ of 60, experience severe spatial-visual problems, and suffer from cardiovascular and other health issues. Despite their desire to befriend people, they have difficulty creating and maintaining social relationships, something that is not at all understood but can afflict many people without WS.

In the new study, led by Dr. Julie R. Korenberg, a University of Utah professor and Salk adjunct professor, the scientists conducted a trial with 21 participants, 13 who have WS and a control group of eight people without the disorder. The participants were evaluated at the Cedars-Sinai Medical Center in Los Angeles. Because music is a known strong emotional stimulus, the researchers asked participants to listen to music.

Before the music was played, the participants’ blood was drawn to determine a baseline level for oxytocin, and those with WS had three times as much of the hormone as those without the syndrome. Blood also was drawn at regular intervals while the music played and was analyzed afterward to check for real-time, rapid changes in the levels of oxytocin and AVP. Other studies have examined how oxytocin affects emotion when artificially introduced into people, such as through nasal sprays, but this is one of the first significant studies to measure naturally occurring changes in oxytocin levels in rapid, real time as people undergo an emotional response.

There was little outward response to the music, but when the blood samples were analyzed, the researchers were happily surprised. The analyses showed that the oxytocin levels, and to a lesser degree AVP, had not only increased but begun to bounce among WS participants while among those without WS, both the oxytocin and AVP levels remained largely unchanged as they listened to music.

Korenberg believes the blood analyses strongly indicate that oxytocin and AVP are not regulated correctly in people with WS, and that the behavioral characteristics unique to people with WS are related to this problem.

"This shows that oxytocin quite likely is very involved in emotional response," Korenberg says.

To ensure accuracy of results, those taking the test also were asked to place their hands in 60-degree Fahrenheit water to test for negative stress, and the same results were produced as when they listened to music. Those with WS experienced an increase in oxytocin and AVP, while those without the syndrome did not.

In addition to listening to music, study participants already had taken three social behavior tests that evaluate willingness to approach and speak to strangers, emotional states, and various areas of adaptive and problem behavior. Those test results suggest that increased levels of oxytocin are linked to both increased desire to seek social interaction and decreased ability to process social cues, a double-edged message that may be very useful at times, for example, during courtship, but damaging at others, as in WS.

"The association between abnormal levels of oxytocin and AVP and altered social behaviors found in people with Williams Syndrome points to surprising, entirely unsuspected deleted genes involved in regulation of these hormones and human sociability," Korenberg said. "It also suggests that the simple characterization of oxytocin as ‘the love hormone’ may be an overreach. The data paint a far more complicated picture."

In particular, the study results indicate that the missing genes affect the release of oxytocin and AVP through the hypothalamus and the pituitary gland. About the size of a pearl, the hypothalamus is located just above the brain stem and produces hormones that control body temperature, hunger, mood, sex drive, sleep, hunger and thirst, and the release of hormones from many glands, including the pituitary. The pituitary gland, about the size of a pea, controls many other glands responsible for hormone secretion.

Overall, the researchers say, their findings paint a very hopeful picture, and the study holds promise for speeding progress in treating WS, and perhaps Autism and anxiety through regulation of these key players in human brain and emotion, oxytocin and vasopressin.

Provided by Salk Institute

Source: medicalxpress.com

Filed under WS brain neuroscience oxytocin science psychology

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Balancing connections for proper brain function

June 22, 2012

Neuropsychiatric conditions such as autism, schizophrenia and epilepsy involve an imbalance between two types of synapses in the brain: excitatory synapses that release the neurotransmitter glutamate, and inhibitory synapses that release the neurotransmitter GABA. Little is known about the molecular mechanisms underlying development of inhibitory synapses, but a research team from Japan and Canada has reported that a molecular signal between adjacent neurons is required for the development of inhibitory synapses.

Figure 1: Compared with the brains of normal animals (left), mice lacking the Slitrk3 gene (right) have a reduced density of inhibitory synapses in the hippocampus. Reproduced from Ref. 1 © 2012 Jun Aruga, RIKEN Brain Science Institute

In earlier work, the researchers—led by Jun Aruga of the RIKEN Brain Science Institute, Wako, and Ann Marie Craig of the University of British Colombia, Vancouver—showed that a membrane protein called Slitrk2 organizes signaling molecules at synapses. They therefore tested whether five related proteins are involved in inhibitory synapse development. They cultured immature hippocampal neurons with non-neural cells expressing each of the six Slitrk proteins. They found that Slitrk3, but not other Slitrk proteins, induced clustering of VGAT, a GABA transporter protein found only at inhibitory synapses.

The researchers also examined the localization of Slitrk3 by tagging it with yellow fluorescent protein and introducing it into cultured hippocampal cells. This revealed that Slitrk3 co-localizes in the dendrites of neurons with gephyrin, a scaffold protein found only in inhibitory synapses. They then blocked Slitrk3 synthesis, and found that it led to a significant reduction in the number of inhibitory synapses.

To confirm these findings, the researchers generated a strain of genetically engineered mice lacking the Slitrk3 gene. These animals had significantly fewer inhibitory synapses than normal animals (Fig. 1), and therefore impaired neurotransmission of GABA. They were also susceptible to epileptic seizures. From a screen for proteins that bind to Slitrk3, Aruga, Craig and colleagues identified the protein PTPδ as its only binding partner. Introduction of PTPδ fused to yellow fluorescent protein to cultured hippocampal neurons showed that it is expressed in neuronal dendrites and cell bodies, but not in axons. Blocking PTPδ synthesis prevented the induction of inhibitory synapses by the Slitrk3 protein.

These results demonstrated that the interaction between Slitrk3 on dendrites and PTPδ on axons of adjacent cells is required for the proper development of inhibitory synapses and for inhibitory neurotransmission in the brain.

“We are now examining whether the balance of excitatory and inhibitory synapses is affected by other members of the Slitrk protein family,” says Aruga. “It is possible that Slitrk3 and other Slitrk proteins are acting synergistically or antagonistically. We are also clarifying whether Slitrk3 is involved in any neurological disorders.”

Provided by RIKEN

Source: medicalxpress.com

Filed under science neuroscience brain psychology synapses

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We have developed a novel experimental platform, referred to as a substitutional reality (SR) system, for studying the conviction of the perception of live reality and related metacognitive functions. The SR system was designed to manipulate people’s reality by allowing them to experience live scenes (in which they were physically present) and recorded scenes (which were recorded and edited in advance) in an alternating manner without noticing a reality gap. All of the naïve participants (n = 21) successfully believed that they had experienced live scenes when recorded scenes had been presented. Additional psychophysical experiments suggest the depth of visual objects does not affect the perceptual discriminability between scenes, and the scene switch during head movement enhance substitutional performance. The SR system, with its reality manipulation, is a novel and affordable method for studying metacognitive functions and psychiatric disorders.

Substitutional Reality System: A Novel Experimental Platform for Experiencing Alternative Reality

We have developed a novel experimental platform, referred to as a substitutional reality (SR) system, for studying the conviction of the perception of live reality and related metacognitive functions. The SR system was designed to manipulate people’s reality by allowing them to experience live scenes (in which they were physically present) and recorded scenes (which were recorded and edited in advance) in an alternating manner without noticing a reality gap. All of the naïve participants (n = 21) successfully believed that they had experienced live scenes when recorded scenes had been presented. Additional psychophysical experiments suggest the depth of visual objects does not affect the perceptual discriminability between scenes, and the scene switch during head movement enhance substitutional performance. The SR system, with its reality manipulation, is a novel and affordable method for studying metacognitive functions and psychiatric disorders.

Substitutional Reality System: A Novel Experimental Platform for Experiencing Alternative Reality

Filed under science neuroscience perception psychology

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Eating Disorder Behaviors and Weight Concerns Are Common in Women Over 50

ScienceDaily (June 21, 2012) — Eating disorders are commonly seen as an issue faced by teenagers and young women, but a new study reveals that age is no barrier to disordered eating. In women aged 50 and over, 3.5% report binge eating, nearly 8% report purging, and more than 70% are trying to lose weight. The study published in the International Journal of Eating Disorders revealed that 62% of women claimed that their weight or shape negatively impacted on their life.

The researchers, led by Dr Cynthia Bulik, Director of the University of North Carolina Eating Disorders Program, reached 1,849 women from across the USA participating in the Gender and Body Image Study (GABI) with a survey titled, ‘Body Image in Women 50 and Over — Tell Us What You Think and Feel.’

"We know very little about how women aged 50 and above feel about their bodies," said Bulik. "An unfortunate assumption is that they ‘grow out of’ body dissatisfaction and eating disorders, but no one has really bothered to ask. Since most research focuses on younger women, our goal was to capture the concerns of women in this age range to inform future research and service planning."

The average age of the participants was 59, while 92% were white. More than a quarter, 27%, were obese, 29% were overweight, 42% were normal weight and 2% were underweight.

Results revealed that eating disorder symptoms were common. About 8% of women reported purging in the last five years and 3.5% reported binge eating in the last month. These behaviors were most prevalent in women in their early 50s, but also occurred in women over 75.

When it came to weight issues, 36% of the women reported spending at least half their time in the last five years dieting, 41% checked their body daily and 40% weighed themselves a couple of times a week or more.

62% of women claimed that their weight or shape negatively impacted their life, 79% said that it affected their self-perception and 64% said that they thought about it daily.

The women reported resorting to a variety of unhealthy methods to change their body, including diet pills (7.5%), excessive exercise (7%), diuretics (2.5%), laxatives (2%) and vomiting (1%).

Two-thirds, 66%, were unhappy with their overall appearance and this was highest when it came to their stomach, 84%, and shape, 73%.

"The bottom line is that eating disorders and weight and shape concerns don’t discriminate on the basis of age," concluded Bulik. "Healthcare providers should remain alert for eating disorder symptoms and weight and shape concerns that may adversely influence women’s physical and psychological wellbeing as they mature."

Source: Science Daily

Filed under science neuroscience psychology eating disorders

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Functional Links Between Autism and Genes Explained

ScienceDaily (June 21, 2012) — A pioneering report of genome-wide gene expression in autism spectrum disorders (ASDs) finds genetic changes that help explain why one person has an ASD and another does not. The study, published by Cell Press on June 21 in The American Journal of Human Genetics, pinpoints ASD risk factors by comparing changes in gene expression with DNA mutation data in the same individuals. This innovative approach is likely to pave the way for future personalized medicine, not just for ASD but also for any disease with a genetic component.

ASDs are a heterogeneous group of developmental conditions characterized by social deficits, difficulty communicating, and repetitive behaviors. ASDs are thought to be highly heritable, meaning that they run in families. However, the genetics of autism are complex.

Researchers have found rare changes in the number of copies of defined genetic regions that associate with ASD. Although there are some hot-spot regions containing these alterations, very few genetic changes are exactly alike. Similarly, no two autistic people share the exact same symptoms. To discover how these genetic changes might affect gene transcription and, thus, the presentation of the disorder, Rui Luo, a graduate student in the Geschwind lab at UCLA, studied 244 families in which one child (the proband) was affected with an ASD and one was not.

In addition to identifying several potential new regions where copy-number variants (CNVs) are associated with ASDs, Geschwind’s team found genes within these regions to be significantly misregulated in ASD children compared with their unaffected siblings. “Strikingly, we observed a higher incidence of haploinsufficient genes in the rare CNVs in probands than in those of siblings, strongly indicating a functional impact of these CNVs on expression,” says Geschwind. Haploinsuffiency occurs when only one copy of a gene is functional; the result is that the body cannot produce a normal amount of protein. The researchers also found a significant enrichment of misexpressed genes in neural-related pathways in ASD children. Previous research has found that these pathways include other genetic variants associated with autism, which Geschwind explains further legitimizes the present findings.

Source: Science Daily

Filed under science neuroscience psychology autism genetics

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Where is the Love?

June 21, 2012 By Janice Wood

Thanks to science, we know that love lives in the brain, not the heart.

Now a new international study has mapped out where love and sexual desire are in the brain.

“No one has ever put these two together to see the patterns of activation,” says Dr. Jim Pfaus, professor of psychology at Concordia University.

“We didn’t know what to expect –the two could have ended up being completely separate. It turns out that love and desire activate specific but related areas in the brain.”

Working with colleagues in the United States and Switzerland, Pfaus analyzed the results of 20 separate studies that examined brain activity while subjects engaged in tasks such as viewing erotic pictures or looking at photographs of their significant others. Pooling this data enabled the scientists to form a map of love and desire in the brain.

They found that two brain structures, the insula and the striatum, are responsible for tracking the progression from sexual desire to love.

The insula is a portion of the cerebral cortex folded deep within an area between the temporal lobe and the frontal lobe, while the striatum is located nearby, inside the forebrain.

According to the researchers, love and sexual desire activate different areas of the striatum. The area activated by sexual desire is usually turned on by things that are inherently pleasurable, such as sex or food.

The area activated by love is involved in the process of conditioning in which things paired with reward or pleasure are given inherent value. That is, as feelings of sexual desire develop into love, they are processed in a different place in the striatum, the researchers explain.

This area of the striatum is also the part of the brain associated with drug addiction. Pfaus says there is good reason for this.

“Love is actually a habit that is formed from sexual desire as desire is rewarded,” he explains. “It works the same way in the brain as when people become addicted to drugs.”

However, the habit is not a bad one, he said, noting that love activates different pathways in the brain that are involved in monogamy and pair bonding. Some areas in the brain are actually less active when a person feels love than when they feel desire, he added.

“While sexual desire has a very specific goal, love is more abstract and complex, so it’s less dependent on the physical presence someone else,” says Pfaus.

Source: PsychCentral

Filed under science neuroscience brain psychology

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Mind games: Mental exercises are key to better brain function

June 20, 2012 By Robin Erb

Go ahead - do it: Grab a pencil. Right now. Write your name backward. And upside down. Awkward, right?

But if researchers and neurologists are correct, doing exercises like these just might buy you a bit more time with a healthy brain.

Some research suggests that certain types of mental exercises - whether they are memory games on your mobile device or jotting down letters backward - might help our gray matter maintain concentration, memory and visual and spatial skills over the years.

"There is some evidence of a use-it-or-lose-it phenomenon," says Dr. Michael Maddens, chief of medicine at Beaumont Hospital, Royal Oak, Mich.

Makers of computer brain games, in fact, are tapping into a market of consumers who have turned to home treadmills and gym memberships to maintain their bodies, and now worry that aging might take its toll on their mental muscle as well.

But tweaking every day routines can help.

Like brushing your teeth with your non-dominant hand. Or crossing your arms the opposite way you’re used to, says Cheryl Deep, who leads “Brain Neurobics” sessions on behalf of the Wayne State Institute of Gerontology.

At a recent session in Novi, Mich., Deep encouraged several dozen senior citizens to flip the pictures in their homes upside-down. It might baffle houseguests, but the exercise crowbars the brain out of familiar grooves cut deep by years of mindless habit.

"Every time you walk past and look, your brain has to rotate that image," Deep says. "Brain neurobics is about getting us out of those ruts, those pathways, and shaking things up."

Participants were asked to call out the color of ink that flashed on a screen in front them. The challenge: The colors spelled out names of other colors. Blue ink spelled o-r-a-n-g-e, for example.

Several in the crowd at Waltonwood Senior Living hesitated - a few scrunching up faces in concentration. The first instinct is to say “orange.”

In another exercise, participants had to try to name as many red foods as possible. Apple? Sure that’s an easy one. It took a while, but the crowd eventually made its way to pomegranate and pimento.

Elissa and Hal Leider chuckled with friends as they tested their recall.

Hal Leider, 82, a retired carpenter, was diagnosed with early-stage Alzheimer’s, and he tries to challenge himself mentally and physically - bowling and shooting pool and playing poker: “I think anything we can do might be helpful,” says Elissa Leider, 74.

The idea of mental workouts marks a dramatic shift in how we understand the brain these days.

"We want to stretch and flex and push" the brain, says Moriah Thomason, assistant professor in Wayne State University School of Medicine’s pediatrics department and in the Merrill Palmer Skillman Institute for Child and Family Development

Thomason also is a scientific adviser to http://www.Lumosity.com, one of the fastest-growing brain game websites.

"We used to think that what you’re born with is what you have through life. But now we understand that the brain is a lot more plastic and flexible than we ever appreciated," she says.

Still, like the rest of your body, aging takes its toll, she says.

The protective covering of the neural cells - white matter - begins to shrink first. Neural and glial cells, often called the gray matter, begin to shrink as well, but more slowly. Neurotransmitters, or chemical messengers, decrease.

But challenging the brain stimulates neural pathways - those tentacles that look like tree branches in a cluster of brain cells. It boosts the brain’s chemistry and connectivity, refueling the entire engine.

"Certain activities will lay more neural pathways that can be more readily re-engaged," Thomason says. "The hope is that there are ways to train and strengthen these pathways."

Maddens explains it this way: Consider the neurons of your brain like electrical wires and the white matter like the insulation. When the insulation breaks down over time, things can misfire.

In labs, those who engaged in mentally challenging games do, in fact, show improvement in cognitive functioning. They get faster at speed games and stronger in memory games, for example.

What’s less clear is whether this improvement transfers to everyday tasks, like remembering where you parked the car or the name of your child’s teacher, both Thomason and Maddens say.

But when it comes to the link between physical exercise and the brain, researchers and clinicians agree: physical exercise is good for the brain; it has also been linked to lower rates of chronic disease. Good nutrition is essential too.

Oxygen, itself, is essential, Deep said: “Your brain is an oxygen hog.”

Diet, exercise and mental maneuvers all may boost brain health in ways science still doesn’t understand. In the best cases, the right mix might stave off the effects of Alzheimer’s and other age-related disease too, Maddens says.

All this is good news for an aging, stressed out, and too-busy society, he says.

Reading a book, engaging with friends or going out for a walk and paying attention to what’s around you - that’s not really about goofing off. Rather, it’s critical time that stimulates neural pathways and boosts the odds of long-time brain health.

"It’s talking to friends. It’s getting out socially. It’s engaging in life. The question is ‘How do I force myself to learn?’" Thomason says.

The same might be true when it comes to mentally changing computer games.

Says Maddens: “Would I have patients playing computer games eight hours a day in hopes that they can delay Alzheimer’s by two months? No. But you can enjoy (playing such games) and possibly get a benefit from it, too.”

Read more …

Filed under science neuroscience brain psychology

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Confusion Can Be Beneficial for Learning

ScienceDaily (June 20, 2012) — Most of us assume that confidence and certainty are preferred over uncertainty and bewilderment when it comes to learning complex information. But a new study led by Sidney D’Mello of the University of Notre Dame shows that confusion when learning can be beneficial if it is properly induced, effectively regulated and ultimately resolved.

Most of us assume that confidence and certainty are preferred over uncertainty and bewilderment when it comes to learning complex information. But a new study shows that confusion when learning can be beneficial if it is properly induced, effectively regulated and ultimately resolved. (Credit: © Ana Blazic Pavlovic / Fotolia)

The study will be published in a forthcoming issue of the journal Learning and Instruction.

Notre Dame psychologist and computer scientist D’Mello, whose research areas include artificial intelligence, human-computer interaction and the learning sciences, together with Art Graesser of the University of Memphis, collaborated on the study, which was funded by the National Science Foundation.

They found that by strategically inducing confusion in a learning session on difficult conceptual topics, people actually learned more effectively and were able to apply their knowledge to new problems.

In a series of experiments, subjects learned scientific reasoning concepts through interactions with computer-animated agents playing the roles of a tutor and a peer learner. The animated agents and the subject engaged in interactive conversations where they collaboratively discussed the merits of sample research studies that were flawed in one critical aspect. For example, one hypothetical case study touted the merits of a diet pill, but was flawed because it did not include an appropriate control group. Confusion was induced by manipulating the information the subjects received so that the animated agents sometimes disagreed with each other and expressed contradictory or incorrect information. The agents then asked subjects to decide which opinion had more scientific merit, thereby putting the subject in the hot spot of having to make a decision with incomplete and sometimes contradictory information.

In addition to the confusion and uncertainty triggered by the contradictions, subjects who were confused scored higher on a difficult post-test and could more successfully identify flaws in new case studies.

"We have been investigating links between emotions and learning for almost a decade, and find that confusion can be beneficial to learning if appropriately regulated because it can cause learners to process the material more deeply in order to resolve their confusion," D’Mello says.

According to D’Mello, it is not advisable to intentionally confuse students who are struggling or induce confusion during high-stakes learning activities. Confusion interventions are best for higher-level learners who want to be challenged with difficult tasks, are willing to risk failure, and who manage negative emotions when they occur.

"It is also important that the students are productively instead of hopelessly confused. By productive confusion, we mean that the source of the confusion is closely linked to the content of the learning session, the student attempts to resolve their confusion, and the learning environment provides help when the student struggles. Furthermore, any misleading information in the form of confusion-induction techniques should be corrected over the course of the learning session, as was done in the present experiments."

According to D’Mello, the next step in this body of research is to apply these methods to some of the more traditional domains such as physics, where misconceptions are common.

Source: Science Daily

Filed under science neuroscience brain psychology learning

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