Working Memory - Training

Training

One theory of attention-deficit hyperactivity disorder states that ADHD can lead to deficits in working memory. Studies suggest that working memory can be improved by training in ADHD patients through computerized programs. This random controlled study has found that a period of working memory training increases a range of cognitive abilities and increases IQ test scores. Consequently, this study supports previous findings suggesting that working memory underlies general intelligence. Another study of the same group has shown that, after training, measured brain activity related to working memory increased in the prefrontal cortex, an area that many researchers have associated with working memory functions. It has been shown that working memory training leads to measurable density changes for cortical dopamine neuroreceptors in test persons.

A controversial study has shown that training with a working memory task (the dual n-back task) improves performance on a very specific fluid intelligence test in healthy young adults. The study's conclusion that improving or augmenting the brain's working memory ability increases fluid intelligence is backed by some and questioned by others. The study was replicated in 2010, but two studies published in 2012 failed to reproduce the effect.

In Torkel Klingberg's 2009 book The Overflowing Brain, he proposes that working memory is enhanced through exposure to excess neural activation. The brain map of an individual, he argues, can be altered by this activation to create a larger area of the brain activated by a particular type of sensory experience. An example would be that in learning to play guitar, the area activated by sensory impressions of the instrument is larger in the brain of a player than it is in a nonplayer.

There is evidence that optimal working memory performance links to the neural ability to focus attention on task-relevant information and ignore distractions, and that practice-related improvement in working memory is due to increasing these abilities.

Working memory performance may also be increased by high intensity exercise. A study was conducted with both sedentary and active females 18–25 years old in which the effects of short-term exercise to exhaustion on working memory was measured. While the working memory of the subjects decreased during and immediately after the exercise bouts, it was shown that the subjects' working memory had an increase following recovery.

However a recent review paper has called into question much of the "success" of working memory training studies. Shipstead et al. (2010) point out that working memory training studies are plagued with poor experimental design. The majority of training studies utilize a no-contact control group making it impossible to determine whether any benefit of training is due to actual improvement or a Hawthorne effect.