Extensive Experience Enables Experts to Enjoy Enormous Edge in Working Memory through Encapsulation

Alas, astute authors always avoid alliteration.

Although it's nearly a decade old, chapter two--"How Experts Differ from Novices"--of How People Learn: Brain, Mind, Experience, and School contains many points relevant to the brain's capacity to process multiple tasks concurrently. By the title, one can tell that the chapter contrasts the characteristics of experts with those of novices. One characteristic involves experts' extensive experience. It allows them to encapsulate large quantities of information into chunks that are small enough for their working memory to hold (p 20). Another characteristic involves the logical organization and interconnectedness of experts' knowledge which makes recall of it rapid and effortless. This allows experts to call up salient portions of their knowledge without overwhelming their working memory with irrelevant information (p 26).

How do these observations relate to the brain's capacity to process multiple tasks concurrently? One part of the answer is that working memory imposes limits on multitasking behavior. Since working memory is a finite resource, when it is exhausted, subsequent information cannot be processed. Thus, if one's entire working memory is already in use by a task--an amateur playing chess, for example--then trying to engage in additional activities--say, counting by 3--would cause his working memory to overflow and one of the tasks would suffer from data loss. On the other hand, if one is able to compress and reduce the information flowing through his working memory, then he would have capacity left over for other tasks.

Consider the following illustration: When a Grandmaster looks at a chessboard, he "sees" the entire board in a single glance, compressing all of 32 pieces into a single board position; one item places a much lower load on working memory than 32. Additionally, rather than calling to mind all possible moves from the given position, a Grandmaster only considers moves that make sense under the circumstances. This, too, places a much lower load on working memory. The result? The Grandmaster has compressed and reduced the information flowing through his working memory, so he has capacity left over for other tasks...such as counting his tournament winnings!

Could it be that the reason training increases one's ability to perform multiple tasks concurrently is because trainees are gaining enough experience that it allows them to compress relevant information and reduce irrelevant information? Seems plausible. Would it also have a similar effect on task switching? That's tough to say. Task switching is at least superficially similar to multitasking--i.e., the behaviors people can observe look the same. But do the similarities run deeper? Does the brain handle them similarly? Stay tuned.