A workout for working memory

New research suggests that mental exercises powerfulness enhance one of the brains exchange components for ratiocination and problem-solving.People may be able to remember a nearly infinite number of facts, still only a handful of detailsheld in works repositingcan be accessed and dole outed at any given moment. Its the reason why a person might forget to buy an item or two on a mental grocery list, or why most the great unwashed adopt difficulty adding together large number.In fact, work(a) recollection could be the basis for widely distributed intelligence and reasoning Those who can h octogenarian many items in their mind may be well equipped to consider contrary angles of a complex problem simultaneously.If psychologists could help people expand their working-memory content or drop it function much(prenominal)(prenominal) efficiently, everyone could benefit, from chess masters to learning-disabled children, says Torkel Klingberg, MD, PhD, an assistant cognitiv e neuroscience professor at the Karolinska Institute in Sweden. Children with attention-deficit hyperactivity disorder (ADHD), for example, might especially benefit from working-memory training, says Rosemary Tannock, PhD, a psychologist and psychiatry professor at The infirmary for Sick Children in Toronto.It could be that working-memory problems give rise to observable behavioral symptoms of ADHD distractibility and also shortsighted academic achievement, she says. Working-memory deficits might also underpin some reading disabilities, as it controls the ability to recall haggling read earlier in a sentence, says Tannock.But howor even ifworking memory can be expanded through training remains a topic of hot contention among psychologists. Some manage that working memory has a imbed limit of about four items, and that individual differences in working memory arise from the ability to group small bits of information into larger chunks. However, new research suggests that working- memory capacitor could expand with practicea finding that could shed new light on this central offend of the minds architecture, as well as potentially lead to treatments for ADHD or other learning disabilities.Functional limitationsOne much(prenominal) studyby researchers at Syracuse Universityhit upon the potential trainability while attempting to resolve a tip over in the literary productions on the limits of working memory.Since the 1950s, psychologists beat be one aspect of working memorysome periods referred to as the focus of attentionto sire severe limitations. For example, George Miller, PhDa founder of cognitive psychological science and a psychology professor at Princeton Universityestablished that people generally cant recall lists of numbers more than seven digits long.Those who exceeded that limit tended to start smaller groups of numbers into larger ones, using a process called chunking. For example, people familiar with U.S. intelligence agencies would see t he letter group FBICIA as two chunks, rather the six letters, and that set of letters would only occupy two slots in a persons memory, rather than six.In recent years, however, evidence is rise that the limitation of working memory is somewhere between one and four information chunks.The downward rescript results from new techniques to keep people from chunking information, which can create the illusion of greater fundamental retentivity capacity, says Nelson Cowan, PhD, a psychology professor at the University of MissouriColumbia. In one common chunking-prevention method, participants repeat empty phrases over and over while performing working memory tasks such as memorizing lists of numbers.A recent literature review by Cowan, published in Behavioral and Brain Sciences (Vol. 24, No. 1, pages 87185), makes the case that a manikin of working-memory measures all converge on a set limit of four items.Other researchers rush suggested that working-memory capacity is limited even f urtherto just a single item. In a study by Brian McElree, PhD, a psychology professor at New York University, participants underwent a test of working memory called n-back.In the task, the participants read a series of numbers, presented one at a time on a computer screen. In the easiest version of the task, the computer presents a new digit, and then prompts participants to recall what number immediately preceded the true one. More difficult versions might ask participants to recall what number appeared two, three or four digits ago.McElree found that participants recalled the immediately preceding numbers in a fraction of the time it took them to recall numbers presented more than one number agoa finding published in the Journal of Experimental psychological science Learning, Memory and Cognition (Vol. 27, No. 1, pages 817835.)There is clear and compelling evidence of one unit universe maintained in focal attention and no direct evidence for more than one item of information ex tended over time, says McElree.In an attempt to reconcile the two theories, psychology professor Paul Verhaeghen, PhD, and his colleagues at Syracuse University replicated McElrees experiment, but tracked participants repartee times as they practiced at the task for 10 hours over cinque days. (See November Monitor, page 35.)We found that by the end of day fivetheir working memory capacity had expanded from one to four items, but not to five, says Verhaeghen. It seems that both theories are correct.The focus of attention might expand as other working-memory processes become automated, Verhaeghen says. Perhaps practice improves the process of attaching a position to a number, freeing up the mind to recall up to four numbers, he notes.Some researchers believe the practice nucleus uncovered by Verhaeghen reflects more efficient information encoding rather than expanded working-memory capacity. According to McElree, the response time measures used by Verhaeghen do not provide pure mea sures of memory-retrieval speed, and the changes in response time with practice could indicate that participants in his study simply became more practiced at encoding numbers vividly, he says.If Verhaeghens findings can be replicated using other tasks, it could change how scientists conceptualize working-memory limitations. Rather than there world a set limitation, working-memory capacity could improve through practicesuggesting that those with working-memory problems could improve their capacities through repetition. However, practice would deprivation to occur on a task-by-task basis, says Verhaeghen, and, as he points out, It is doubtful that practice on n-back generalizes to anything in original life.Stretching the limitsNew research on children with ADHD, however, might show tasks such as n-back can improve working memory in general, and could help children with the condition.People with ADHD tend to have difficulty with working-memory capacity, and that deficit could be tr usty for their tendency to be distracted and resulting problems at school, says Tannock.Seeking to alleviate such difficulties with his research, Klingberg ran a randomized controlled trial of 53 children with ADHD in which half of the participants practiced working-memory tasks that gradually increased in difficulty.The other half finished tasks that did not get harder as the children became better at them. Both groups of childrenwho were 7 to 12 years oldpracticed tasks such as recalling lists of numbers for 40 minutes a day over five weeks.The children who practiced with increasingly difficult memory tasks performed better on two working memory testswhich were different than the practice tasksthan the control group, reported Klingberg in the Journal of the American honorary society of Child & Adolescent psychological medicine (Vol. 44, No. 2, pages 177186.)In addition, the parents of children with memory training reported a reduction in their childrens hyperactivity and inattent ion three months aft(prenominal) the intervention, while the parents of the control group participants did not.Subsequent, yet-unpublished experiments build on those results, Klingberg says.We have looked at other groups too adults with stroke, four-year-old adults without ADHD, children withtraumatic brain injuries, he says. A general pattern weve found is as long as you have working-memory problems and you have the ability to train, you can improve your abilities.Some researchers suggest that memory training may have more of an military force on motivation than working memory.It seems to me that children in the training group may have learned to have a better attitude toward the testing situation, whereas children in the control groupwho restate easy problemsmay have learned that the testing situation was boring and uninteresting, says Cowan. The differences that emerged on a variety of tasks could be the result of better motivation and attitude rather than a basic improvement in working memory.Or, says Klaus Oberauer, PhD, a psychology professor and memory researcher at the University of Bristol in England, the practice effect in both Klingbergs studies might result from people learning to use their limited working-memory capacity more efficientlyperhaps by grouping information into larger chunks or by enlisting long-run memory.I think the practice effect they found basically is just an ordinary practice effect, in that everything gets faster, he says.So, even if working memory cant be expanded, adults with grocery lists and children with ADHD may be able to make better use of what little space is available by practicing the task itself or repeating tests of general working memory. And, in the end, the milk gets bought and the reading assignment finished.ReferenceCowan, N. (2005). Working-memory capacity limits in a theoretical context. In C. Izawa & N. Ohta (Eds.), Human learning and memory Advances in theory and application The 4th Tsukuba Internatio nal Conference on Memory. (pp. 155175). Mahwah, NJ Erlbaum.Klingberg, T., Fernell, E., Olesen, P.J., Johnson, M., Gustafsson, P., Dahlstrom, K., et al. (2005). Computerized training of working memory in children with ADHDA randomized, controlled trial. Journal of the American Academy of Child & Adolescent Psychiatry, 44(2), 177186.Martinussen, R., Hayden J., Hogg-Johnson, S., & Tannock, R. (2005). A meta-analysis of working memory components in children with Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 44(4), 377384.McElree, B. (2001). Working memory and focal attention. Journal of Experimental Psychology Learning, Memory, & Cognition, 27(3), 817835.Pernille, J.O., Westerberg, H., & Klingberg, T. (2004). Increased prefrontal and parietal activity after training in working memory. Nature Neuroscience, 7(1), 7579.Verhaeghen, P., Cerella, J., & Basak, C. (2004). A working memory workout How to expand the focus of serial att ention from one to four items in 10 hours or less. Journal of Experimental Psychology Learning, Memory, & Cognition, 30(6), 13221337.