Posts tagged Neuroscience 2012
Articles and news from the latest research reports.
A little science goes a long way: Engaging kids improves math, language scores
A Washington State University researcher has found that engaging elementary school students in science for as little as 10 hours a year can lead to improved test scores in math and language arts.
Samantha Gizerian, a clinical assistant professor in WSU’s Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, saw improved test scores among fourth-grade students in South Los Angeles after students from the Charles R. Drew University of Medicine and Science gave 10 one-hour presentations on science.
"A lot of students say things like, ‘I didn’t know science was fun,’” says Gizerian, who helped with the classes while on the Drew faculty. "And because they think it’s fun, all of a sudden it’s not work anymore. It’s not homework. It’s not something extra that they have to do.”
Might lefties and righties benefit differently from a power nap?
At ‘rest,’ right hemisphere of the brain ‘talks’ more than the left hemisphere does
People who like to nap say it helps them focus their minds post a little shut eye. Now, a study from Georgetown University Medical Center may have found evidence to support that notion.
The research, presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience, found that when participants in a study rested, the right hemisphere of their brains talked more to itself and to the left hemisphere than the left hemisphere communicated within itself and to the right hemisphere – no matter which of the participants’ hands was dominant. (Neuroscientists say right-handed people use their left hemisphere to a greater degree, and vice versa.)
Results of this study, the first known to look at activity in the two different hemispheres during rest, suggests that the right hemisphere “is doing important things in the resting state that we don’t yet understand,” says Andrei Medvedev, Ph.D., an assistant professor in the Center for Functional and Molecular Imaging at Georgetown. The activities being processed by the right hemisphere, which is known to be involved in creative tasks, could be daydreaming or processing and storing previously acquired information. “The brain could be doing some helpful housecleaning, classifying data, consolidating memories,” Medvedev says. “That could explain the power of napping. But we just don’t know yet the relative roles of both hemispheres in those processes and whether the power nap might benefit righties more then lefties.”
To find out what happens in the resting state, the research team connected 15 study participants to near-infrared spectroscopy (NIRS) equipment. This technology, which is low cost and portable, uses light to measure changes in oxygenated hemoglobin inside the body.
The study participants wore a cap adorned with optical fibers that delivers infrared light to the outermost layers of the brain and then measures the light that bounces back. In this way, the device can “see” which parts of the brain are most active and communicating at a higher level based on increased use of oxygen in the blood and heightened synchronicity of their activities.
"The device can help delineate global networks inside the brain — how the components all work together," Medvedev says. "The better integrated they are, the better cognitive tasks are performed."
To their surprise, the researchers found that left and right hemispheres behaved differently during the resting state. “That was true no matter which hand a participant used. The right hemisphere was more integrated in right-handed participants, and even stronger in the left-handed,” he says.
Medvedev is exploring the findings for an explanation. And he suggests that brain scientists should start focusing more of their attention on the right hemisphere. “Most brain theories emphasize the dominance of the left hemisphere especially in right handed individuals, and that describes the population of participants in these studies,” Medvedev says. “Our study suggests that looking at only the left hemisphere prevents us from a truer understanding of brain function.”
(Source: eurekalert.org)
New findings illuminate basis in brain for social decisions, reactions
The social brain consists of the structures and circuits that help people understand others’ intentions, beliefs, and desires, and how to behave appropriately. Its smooth functioning is essential to humans’ ability to cooperate. Its dysfunction is implicated in a range of disorders, from autism, to psychopathology, to schizophrenia.
New findings show that:
• Primates employ three different parts of the prefrontal cortex in decisions about whether to give or keep prized treats. These findings illuminate a poorly understood brain circuit, and offer possible insights into human sharing and other social behavior (Steve Chang, PhD, abstract 129.10).
• Different brain regions are engaged in altruistic behavior that is motivated by genuine caring versus altruistic behavior motivated by a concern for reputation or self-image (Cendri Hutcherson, PhD, abstract 129.06).
• The experience of racial discrimination triggers activity in the same brain regions that respond to pain, social rejection, and other stressful experiences (Arpana Gupta, PhD, abstract 402.06).Another recent finding discussed shows that:
• Competition against a human opponent or a computer engages the same parts of the brain, with one exception: the temporal parietal junction is used to predict only a human’s upcoming actions (Ronald Carter, PhD).
Studies report early childhood trauma takes visible toll on brain; changes found in regions controlling heart and behavior
Trauma in infancy and childhood shapes the brain, learning, and behavior, and fuels changes that can last a lifetime, according to new human and animal research released today. The studies delve into the effects of early physical abuse, socioeconomic status (SES), and maternal treatment. Documenting the impact of early trauma on brain circuitry and volume, the activation of genes, and working memory, researchers suggest it increases the risk of mental disorders, as well as heart disease and stress-related conditions in adulthood.
Today’s findings show:
• Physical abuse in early childhood may realign communication between key “body-control” brain areas, possibly predisposing adults to cardiovascular disease and mental health problems (Layla Banihashemi, PhD, abstract 691.12).
• Rodent studies provide insight into brain changes that allow tolerance of pain within mother-pup attachment (Regina Sullivan, PhD, abstract 399.19).
• Childhood poverty is associated with changes in working memory and attention years later in adults; yet training in childhood is associated with improved cognitive functions (Eric Pakulak, PhD, abstract 908.04).
• Chronic stress experienced by infant primates leads to fearful and aggressive behaviors; these are associated with changes in stress hormone production and in the development of the amygdala (Mar Sanchez, PhD, abstract 691.10).Another recent finding discussed shows that:
• Parent education and income is associated with children’s brain size, including structures important for memory and emotion (Suzanne Houston, MA).
Findings reveal brain mechanisms at work during sleep
One in five American adults show signs of chronic sleep deprivation, making the condition a widespread public health problem. Sleeplessness is related to health issues such as obesity, cardiovascular problems, and memory problems.
Today’s findings show that:
• Sleepiness disrupts the coordinated activity of an important network of brain regions; the impaired function of this network is also implicated in Alzheimer’s disease (Andrew Ward, abstract 909.05).
• Sleeplessness plays havoc with communication between the hippocampus, which is vital for memory, and the brain’s “default mode network;” the changes may weaken event recollection (Hengyi Rao, PhD, abstract 626.08).
• In a mouse model, fearful memories can be intentionally weakened during sleep, indicating new possibilities for treatment of post-traumatic stress disorder (Asya Rolls, abstract 807.06).
• Loss of less than half a night’s sleep can impair memory and alter the normal behavior of brain cells (Ted Abel, PhD, abstract 807.13).Other recent findings discussed show:
• How sleep enables the remodeling of memories — including the weakening of irrelevant memories — and the coherent integration of old and new information (Gina Poe, PhD).
• The common logic behind seemingly contradictory theories of how sleep remodels synapses, aiding cognition and memory consolidation (Giulio Tononi, MD, PhD).
Scientists reveal brain circuitry involved in post-traumatic stress and related disorders
Post-traumatic stress disorder (PTSD) is a severe anxiety disorder that can develop after experience of a traumatic or terrifying event, such as those experienced in combat or from sexual aggression. Such events can overwhelm the individual’s ability to cope and lead to a long-lasting disorder. Symptoms include re-experiencing the original trauma through flashbacks or nightmares, often triggered by seemingly innocuous events. PTSD can harm an individual’s relationships, ability to work, to sleep, and other aspects of life.
The lifetime prevalence of PTSD among adult Americans is 8 percent. Neither drug nor behavioral treatments currently available are consistently effective in treating PTSD. Therefore, scientists are studying brain changes associated with PTSD and related cognitive disorders, looking for clues to help in the development of new treatments.
Today’s findings show that:
- A fast-acting antidepressant, ketamine, appears to aid the formation of new nerve connections in the brain, helping to extinguish fearful memories. The mouse study could possibly lead to new PTSD treatments (Neil Fournier, PhD, abstract 399.09).
- In a mouse model, when dopamine neurons in the brain’s reward system are turned on and off with a genetically engineered “light switch,” depressive symptoms also come and go. The research highlights the importance of this neural circuit as a potential target for new depression treatments (Dipesh Chaudhury, PhD, abstract 522.01).
- Brain images of adolescents taken before and after the 2011 Japanese earthquake reveal that pre-existing weakness in certain brain connections could be a risk factor for intensified anxiety and PTSD after a traumatic life experience (Atsushi Sekiguchi, MD, PhD, abstract 168.12).
- Rodent studies show that repeated violent, competitive encounters drive changes in brain activity that shapes the ongoing behavior of losers and winners in distinct ways, and can contribute to depression and/or anxiety (Tamara Franklin, PhD, abstract 399.10).
Other recent findings discussed show:
- How exposure to stress causes molecular changes that weaken the ability of the prefrontal cortex to regulate behavior, thought, and emotion, while strengthening more primitive brain circuits (Amy Arnsten, PhD, abstract 310).
New research reveals more about how the brain processes facial expressions and emotions
Facial mimicry—a social behavior in which the observer automatically activates the same facial muscles as the person she is imitating—plays a role in learning, understanding, and rapport. Mimicry can activate muscles that control both smiles and frowns, and evoke their corresponding emotions, positive and negative. The studies reveal new roles of facial mimicry and some of its underlying brain circuitry.
New findings show that:
- Special brains cells dubbed “eye cells” activate in the amygdala of a monkey looking into the eyes of another monkey, even as the monkey mimics the expressions of its counterpart (Katalin Gothard, MD, PhD, abstract 402.02).
- Social status and self-perceptions of power affect facial mimicry, such that powerful individuals suppress their smile mimicry towards other high-status people, while powerless individuals mimic everyone’s smile (Evan Carr, BS, abstract 402.11).
- Brain imaging studies in monkeys have revealed the specific roles of different regions of the brain in understanding facial identity and emotional expression, including one brain region previously identified for its role in vocal processing (Shih-pi Ku, PhD, abstract 263.22).
- Subconscious facial mimicry plays a strong role in interpreting the meaning of ambiguous smiles (Sebastian Korb, PhD, abstract 402.23).
Another recent finding discussed shows that:
- Early difficulties in interactions between parents and infants with cleft lip appear to have a neurological basis, as change in a baby’s facial structure can disrupt the way adult brains react to a child (Christine Parsons, PhD).
(Image Credit: iStockphoto/Joan Vicent Cantó Roig)
Status affects how readily people return smiles, research reveals
If you smile at your boss and she smiles back, beware. It could be a sign that she does not think too highly of you, according to a study.
People who feel powerful are more likely to mimic the smiles of those they perceive as low status, according to research presented at the annual Society for Neuroscience conference in New Orleans. They are less likely, however, to return the smiles of people they consider of higher status than themselves. And when people are not feeling particularly powerful, they return everyone’s smiles almost equally.
Mimicking other people’s behaviour is an important mechanism of bonding in group situations, according to Evan Carr from the department of psychology at the University of California in San Diego, who led the study. “Mimicry has been shown to help build relationships, and both power and status seem to affect how we unconsciously employ this strategy,” he said.
Power, he said, referred to someone’s internal feeling of being able to take control of others, whereas status was a more externally defined quality. “It’s more to do with perceived reverence or some type of social hierarchy,” said Carr.
Does motherhood dampen cocaine’s effects?
Mother rats respond much differently to cocaine than female rats that have never given birth, according to new University of Michigan research that looks at both behavior and brain chemistry.
The findings may help lay the groundwork for more tailored human addiction treatment, based on scientific understanding of how gender, hormones and life experience impact drug use.
In an oral presentation at the Society for Neuroscience meeting, U-M researcher Jennifer Cummings, Ph.D., summarized findings from experiments with rats at the Molecular and Behavioral Neuroscience Institute, part of the U-M Medical School. She worked with Jill Becker, Ph.D., of the U-M Department of Psychology.
They identified clear differences in how intensely the “pleasure centers” in the mother rats’ brains reacted to the drug, compared with non-mothers. Mother rats’ brains released less of a chemical called dopamine, which helps cause the “high” from cocaine.
They also found an interaction with stress: mother rats that were exposed to periods of increased stress weren’t willing to work as hard to get a dose of cocaine, compared with rats that had never given birth or mother rats that weren’t exposed to the stress – even though the stressed mother rats showed an increased tendency to use cocaine when it was easy to get.
Taken together, the findings suggest that the experience of becoming a mother alters a female’s overall response to cocaine – adding complexity to the issue of how best to treat addiction.
“While we have not yet identified a mechanism to explain these differences, they do suggest that the reward system and brain circuitry affected by cocaine is changed with maternal experience,” says Cummings, a research investigator at MBNI and former postdoctoral fellow in Becker’s laboratory. “The next step is to determine how factors such as hormone changes in pregnancy and early motherhood, and the experience of caring for offspring, might be differentially contributing to this response.”
A tool to quantify consciousness?
Assessing consciousness may seem like the ultimate exercise in subjectivity, but some researchers are moving closer to what they call an objective measure.
The goal is to provide clearer information for families with loved ones living in vegetative or minimally conscious states — conditions that are often caused by brain trauma or cardiac arrest.
“We really need to find a way to be able to measure consciousness reliably,” says Melanie Boly, a postdoctoral fellow at the Belgian National Fund for Research in Liege, Belgium. “For the family, this changes everything,” says Boly, who presented her team’s research on 14 October at the Society for Neuroscience meeting in New Orleans, Louisiana.
Vegetative patients make only reflexive movements and appear insensitive to their surroundings, while minimally conscious patients can make some purposeful movements and even feel pain. Clinically, the differences between these patients can be difficult even for experienced physicians to discern. But legally, the differences are clear.
In 2011, the UK court system denied a family’s request to end life support for their daughter after additional tests revised her initial diagnosis from ‘vegetative’ to ‘minimally conscious’.
To derive a numerical measure of consciousness, Boly and her colleagues pulsed subjects’ heads with a brief electromagnetic wave, then measured neural responses using electrodes stuck to the scalp.
In 32 healthy, awake people, the electromagnetic impulse sent complex patterns of electrical activity reverberating throughout the brain. In healthy sleeping people, or people under general anaesthesia, the brain displayed shorter, simpler responses that stayed closer to the site of the initial stimulation. The researchers quantified these differences in a measure of response complexity.
In six patients diagnosed as vegetative, the electromagnetic pulse elicited responses with complexity indices similar to those in sleeping or anaesthetized healthy subjects. Twelve minimally conscious patients showed slightly more complex responses. And two ‘locked-in’ patients — people who are fully conscious but unable to move or communicate — showed complexity indices similar to healthy, awake subjects.
Boly and her colleagues have previously noted some of these differences across patient groups but with poor reliability for individual patients. With the complexity index, which combines several aspects of the brain’s response, she says, “this is the first time we really have a measure that works at a single-subject level.”
“It’s not going to supplant a clinical assessment,” says Nicholas Schiff, a neurologist at the Weill Cornell Medical College in New York. But he says the complexity index could become a valuable tool for adding some certainty to the subjective process of evaluating patient consciousness.
“I personally would welcome a test that could provide us with objective measurements,” says David Okonkwo, clinical director of the Brain Trauma Research Center at the University of Pittsburgh in Pennsylvania. However, he said much more testing is needed to tell whether the complexity index meets that standard.
“We need more patients,” agrees Boly, “but it’s extremely promising.”
(Source: blogs.nature.com)