Archive for the ‘learning’ Category

Everyone knows it’s easier to learn about a topic you’re curious about. Now, a new study reveals what’s going on in the brain during that process, revealing that such curiosity may give a person a memory boost.

When participants in the study were feeling curious, they were better at remembering information even about unrelated topics, and brain scans showed activity in areas linked to reward and memory.

The results, detailed October 2 in the journal Neuron, hint at ways to improve learning and memory in both healthy people and those with neurological disorders, the researchers said.

“Curiosity may put the brain in a state that allows it to learn and retain any kind of information, like a vortex that sucks in what you are motivated to learn, and also everything around it,” Matthias Gruber, a memory researcher at the University of California, Davis, said in a statement. “These findings suggest ways to enhance learning in the classroom and other settings.”

Gruber and his colleagues put people in a magnetic resonance imaging (MRI) scanner and showed them a series of trivia questions, asking them to rate their curiosity about the answers to those questions. Later, the participants were shown selected trivia questions, then a picture of a neutral face during a 14-second delay, followed by the answer. Afterward, the participants were given a surprise memory test of the faces, and then a memory test of the trivia answers.

Not surprisingly, the study researchers found that people remembered more information about the trivia when they were curious about the trivia answers. But unexpectedly, when the participants were curious, they were also better at remembering the faces, an entirely unrelated task. Participants who were curious were also more likley than others to remember both the trivia information and unrelated faces a day later, the researchers found.

The brain scans showed that, compared with when their curiosity wasn’t piqued, when people were curious, they showed more activation of brain circuits in the nucleus accumbens, an area involved in reward. These same circuits, mediated by the neurochemical messenger dopamine, are involved in forms of external motivation, such as food, sex or drug addiction.

Finally, being curious while learning seemed to produce a spike of activity in the hippocampus, an area involved in forming new memories, and strengthened the link between memory and reward brain circuits.

The study’s findings not only highlight the importance of curiosity for learning in healthy people, but could also give insight into neurological conditions. For example, as people age, their dopamine circuits tend to deteriorate, so understanding how curiosity affects these circuits could help scientists develop treatments for patients with memory disorders, the researchers said.

http://www.livescience.com/48121-curiosity-boosts-memory-learning.html

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MATH

In a lab in Oxford University’s experimental psychology department, researcher Roi Cohen Kadosh is testing an intriguing treatment: He is sending low-dose electric current through the brains of adults and children as young as 8 to make them better at math.

A relatively new brain-stimulation technique called transcranial electrical stimulation may help people learn and improve their understanding of math concepts.

The electrodes are placed in a tightly fitted cap and worn around the head. The device, run off a 9-volt battery commonly used in smoke detectors, induces only a gentle current and can be targeted to specific areas of the brain or applied generally. The mild current reduces the risk of side effects, which has opened up possibilities about using it, even in individuals without a disorder, as a general cognitive enhancer. Scientists also are investigating its use to treat mood disorders and other conditions.

Dr. Cohen Kadosh’s pioneering work on learning enhancement and brain stimulation is one example of the long journey faced by scientists studying brain-stimulation and cognitive-stimulation techniques. Like other researchers in the community, he has dealt with public concerns about safety and side effects, plus skepticism from other scientists about whether these findings would hold in the wider population.

There are also ethical questions about the technique. If it truly works to enhance cognitive performance, should it be accessible to anyone who can afford to buy the device—which already is available for sale in the U.S.? Should parents be able to perform such stimulation on their kids without monitoring?

“It’s early days but that hasn’t stopped some companies from selling the device and marketing it as a learning tool,” Dr. Cohen Kadosh says. “Be very careful.”

The idea of using electric current to treat the brain of various diseases has a long and fraught history, perhaps most notably with what was called electroshock therapy, developed in 1938 to treat severe mental illness and often portrayed as a medieval treatment that rendered people zombielike in movies such as “One Flew over the Cuckoo’s Nest.”

Electroconvulsive therapy has improved dramatically over the years and is considered appropriate for use against types of major depression that don’t respond to other treatments, as well as other related, severe mood states.

A number of new brain-stimulation techniques have been developed, including deep brain stimulation, which acts like a pacemaker for the brain. With DBS, electrodes are implanted into the brain and, though a battery pack in the chest, stimulate neurons continuously. DBS devices have been approved by U.S. regulators to treat tremors in Parkinson’s disease and continue to be studied as possible treatments for chronic pain and obsessive-compulsive disorder.

Transcranial electrical stimulation, or tES, is one of the newest brain stimulation techniques. Unlike DBS, it is noninvasive.

If the technique continues to show promise, “this type of method may have a chance to be the new drug of the 21st century,” says Dr. Cohen Kadosh.

The 37-year-old father of two completed graduate school at Ben-Gurion University in Israel before coming to London to do postdoctoral work with Vincent Walsh at University College London. Now, sitting in a small, tidy office with a model brain on a shelf, the senior research fellow at Oxford speaks with cautious enthusiasm about brain stimulation and its potential to help children with math difficulties.

Up to 6% of the population is estimated to have a math-learning disability called developmental dyscalculia, similar to dyslexia but with numerals instead of letters. Many more people say they find math difficult. People with developmental dyscalculia also may have trouble with daily tasks, such as remembering phone numbers and understanding bills.

Whether transcranial electrical stimulation proves to be a useful cognitive enhancer remains to be seen. Dr. Cohen Kadosh first thought about the possibility as a university student in Israel, where he conducted an experiment using transcranial magnetic stimulation, a tool that employs magnetic coils to induce a more powerful electrical current.

He found that he could temporarily turn off regions of the brain known to be important for cognitive skills. When the parietal lobe of the brain was stimulated using that technique, he found that the basic arithmetic skills of doctoral students who were normally very good with numbers were reduced to a level similar to those with developmental dyscalculia.

That led to his next inquiry: If current could turn off regions of the brain making people temporarily math-challenged, could a different type of stimulation improve math performance? Cognitive training helps to some extent in some individuals with math difficulties. Dr. Cohen Kadosh wondered if such learning could be improved if the brain was stimulated at the same time.

But transcranial magnetic stimulation wasn’t the right tool because the current induced was too strong. Dr. Cohen Kadosh puzzled over what type of stimulation would be appropriate until a colleague who had worked with researchers in Germany returned and told him about tES, at the time a new technique. Dr. Cohen Kadosh decided tES was the way to go.

His group has since conducted a series of studies suggesting that tES appears helpful improving learning speed on various math tasks in adults who don’t have trouble in math. Now they’ve found preliminary evidence for those who struggle in math, too.

Participants typically come for 30-minute stimulation-and-training sessions daily for a week. His team is now starting to study children between 8 and 10 who receive twice-weekly training and stimulation for a month. Studies of tES, including the ones conducted by Dr. Cohen Kadosh, tend to have small sample sizes of up to several dozen participants; replication of the findings by other researchers is important.

In a small, toasty room, participants, often Oxford students, sit in front of a computer screen and complete hundreds of trials in which they learn to associate numerical values with abstract, nonnumerical symbols, figuring out which symbols are “greater” than others, in the way that people learn to know that three is greater than two.

When neurons fire, they transfer information, which could facilitate learning. The tES technique appears to work by lowering the threshold neurons need to reach before they fire, studies have shown. In addition, the stimulation appears to cause changes in neurochemicals involved in learning and memory.

However, the results so far in the field appear to differ significantly by individual. Stimulating the wrong brain region or at too high or long a current has been known to show an inhibiting effect on learning. The young and elderly, for instance, respond exactly the opposite way to the same current in the same location, Dr. Cohen Kadosh says.

He and a colleague published a paper in January in the journal Frontiers in Human Neuroscience, in which they found that one individual with developmental dyscalculia improved her performance significantly while the other study subject didn’t.

What is clear is that anyone trying the treatment would need to train as well as to stimulate the brain. Otherwise “it’s like taking steroids but sitting on a couch,” says Dr. Cohen Kadosh.

Dr. Cohen Kadosh and Beatrix Krause, a graduate student in the lab, have been examining individual differences in response. Whether a room is dark or well-lighted, if a person smokes and even where women are in their menstrual cycle can affect the brain’s response to electrical stimulation, studies have found.

Results from his lab and others have shown that even if stimulation is stopped, those who benefited are going to maintain a higher performance level than those who weren’t stimulated, up to a year afterward. If there isn’t any follow-up training, everyone’s performance declines over time, but the stimulated group still performs better than the non-stimulated group. It remains to be seen whether reintroducing stimulation would then improve learning again, Dr. Cohen Kadosh says.

http://online.wsj.com/news/articles/SB10001424052702303650204579374951187246122?mod=WSJ_article_EditorsPicks&mg=reno64-wsj&url=http%3A%2F%2Fonline.wsj.com%2Farticle%2FSB10001424052702303650204579374951187246122.html%3Fmod%3DWSJ_article_EditorsPicks

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The flip of a single molecular switch helps create the mature neuronal connections that allow the brain to bridge the gap between adolescent impressionability and adult stability. Now Yale School of Medicine researchers have reversed the process, recreating a youthful brain that facilitated both learning and healing in the adult mouse.

Scientists have long known that the young and old brains are very different. Adolescent brains are more malleable or plastic, which allows them to learn languages more quickly than adults and speeds recovery from brain injuries. The comparative rigidity of the adult brain results in part from the function of a single gene that slows the rapid change in synaptic connections between neurons.

By monitoring the synapses in living mice over weeks and months, Yale researchers have identified the key genetic switch for brain maturation a study released March 6 in the journal Neuron. The Nogo Receptor 1 gene is required to suppress high levels of plasticity in the adolescent brain and create the relatively quiescent levels of plasticity in adulthood. In mice without this gene, juvenile levels of brain plasticity persist throughout adulthood. When researchers blocked the function of this gene in old mice, they reset the old brain to adolescent levels of plasticity.

“These are the molecules the brain needs for the transition from adolescence to adulthood,” said Dr. Stephen Strittmatter. Vincent Coates Professor of Neurology, Professor of Neurobiology and senior author of the paper. “It suggests we can turn back the clock in the adult brain and recover from trauma the way kids recover.”

Rehabilitation after brain injuries like strokes requires that patients re-learn tasks such as moving a hand. Researchers found that adult mice lacking Nogo Receptor recovered from injury as quickly as adolescent mice and mastered new, complex motor tasks more quickly than adults with the receptor.

“This raises the potential that manipulating Nogo Receptor in humans might accelerate and magnify rehabilitation after brain injuries like strokes,” said Feras Akbik, Yale doctoral student who is first author of the study.

Researchers also showed that Nogo Receptor slows loss of memories. Mice without Nogo receptor lost stressful memories more quickly, suggesting that manipulating the receptor could help treat post-traumatic stress disorder.

“We know a lot about the early development of the brain,” Strittmatter said, “But we know amazingly little about what happens in the brain during late adolescence.”

Other Yale authors are: Sarah M. Bhagat, Pujan R. Patel and William B.J. Cafferty

The study was funded by the National Institutes of Health. Strittmatter is scientific founder of Axerion Therapeutics, which is investigating applications of Nogo research to repair spinal cord damage.

http://news.yale.edu/2013/03/06/flip-single-molecular-switch-makes-old-brain-young