Scans show learning 'sculpts' the brain's connectionsOctober 09, 2009Spontaneous brain activity formerly thought to be "white noise" measurably changes after a person learns a new task, researchers at Washington University School of Medicine in St. Louis and the University of Chieti, Italy, have shown. Scientists also report that the degree of change reflects how well subjects have learned to perform the task. Their study is published online this week in the Proceedings of the National Academy of Sciences. "Recent studies have shown that in the absence of any overt behavior, and even during sleep or anesthesia, the brain's spontaneous activity is not random, but organized in patterns of correlated activity that occur in anatomically and functionally connected regions," says senior author Maurizio Corbetta, M.D., Norman J. Stupp Professor of Neurology. "The reasons behind the spontaneous activity patterns remain mysterious, but we have now shown that learning causes small changes in those patterns, and that these changes are behaviorally important." At the start of the experiment, Corbetta, graduate students Chris Lewis and Antonello Baldassarre and their colleagues in Italy used functional connectivity magnetic resonance imaging to scan the spontaneous brain activity of 14 volunteers as they sat quietly. Next, researchers scanned the subjects as they spent one to two hours a day for five to seven days learning to watch a display inside the MRI scanner for the brief presence of an inverted "T" in a specific part of the screen. Two sets of brain areas were particularly active during the task: part of the visual cortex that corresponded to the portion of the visual field where subjects were looking for the "T", and areas in the dorsal part of the brain involved in directing attention to the location on the screen. After the visual training, scientists again scanned the subjects' brains while they did nothing. When the subjects rested at the start of the experiment, spontaneous activity in the two parts of the brain that are important to the visual task was either not linked or weakly correlated, with the two regions involved in the upcoming task only occasionally being active at the same time. After learning, though, each region was more likely to be active when the other region wasn't. Subjects who were more successful at the task exhibited a higher degree of this "anti-correlation" between the two regions after learning. Corbetta suggests this learning-induced change in the brain's spontaneous activity may reflect what he calls a "memory trace" for the new skill. The trace makes it easier to use those parts of the brain together again when the same challenge recurs. "It's as though these two brain systems are learning to get out of each other's way," says Corbetta. "After learning, the brain can identify the targets at a glance in a way that requires less direct attention and thus less interaction between the regions involved in the task." In addition to helping "grease" anatomical connections between different brain regions, Corbetta speculates that the changes in spontaneous brain activity may maintain a record of prior experience that constrains the way the same circuitries are recruited at the time of a task. "This suggests that disruption of spontaneous correlated activity may be a common mechanism through which brain function abnormalities manifest in a number of neurological, psychiatric or developmental conditions," he says. Washington University School of Medicine |
|||||||||||||||||||||
| Related Brain Activity Current Events and Brain Activity News Articles Songbirds provide insight into speech production With the help of a little singing bird, Penn State physicists are gaining insight into how the human brain functions, which may lead to a better understanding of complex vocal behavior, human speech production and ultimately, speech disorders and related diseases. Impulsive-Antisocial Personality Traits Linked to a Hypersensitive Brain Reward System Normal individuals who scored high on a measure of impulsive/antisocial traits display a hypersensitive brain reward system, according to a brain imaging study by researchers at Vanderbilt University. U discovery gives insight into brain 'replay' process The hippocampus, a part of the brain essential for memory, has long been known to "replay" recently experienced events. Carnegie Mellon research provides insight into brain's decision-making process Replaying recent events in the area of the brain called the hippocampus may have less to do with creating long-term memories, as scientists have suspected, than with an active decision-making process, suggests a new study by researchers at Carnegie Mellon University and the University of Minnesota Medical School. Why surprises temporarily blind us Reading this story requires you to willfully pay attention to the sentences and to tune out nearby conversations, the radio and other distractions. But if a fire alarm sounded, your attention would be involuntarily snatched away from the story to the blaring sound. After a fight with a partner, brain activity predicts emotional resiliency Common wisdom tells us that for a successful relationship partners shouldn't go to bed angry. But new research from a psychologist at Harvard University suggests that brain activity-specifically in the region called the lateral prefrontal cortex-is a far better indicator of how someone will feel in the days following a fight with his or her partner. Learning helps keep brain healthy, UCI researchers find UC Irvine neurobiologists are providing the first visual evidence that learning promotes brain health - and, therefore, that mental stimulation could limit the debilitating effects of aging on memory and the mind. Critical brain chemical shown to play role in severe depression The next advance in treating major depression may relate to a group of brain chemicals that are involved in virtually all our brain activity, according to a study published today in Biological Psychiatry. Pitt Researchers Report Internal and Environmental Factors Trigger Unique Brain Activity in Teens, Is Key Step in Understanding Causes of Teen Behavior While the otherworldly behavior of teenagers is well documented, University of Pittsburgh researchers have taken a significant step toward finally unraveling the actual brain activity that can drive adolescents to engage in impulsive, self-indulgent, or self-destructive behavior. Brain-controlled cursor doubles as a neural workout Harnessing brain signals to control keyboards, robots or prosthetic devices is an active area of medical research. Now a rare peek at a human brain hooked up to a computer shows that the two can adapt to each other quickly, and possibly to the brain's benefit. More Brain Activity Current Events and Brain Activity News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||