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Excerpt From 'Think Smart: A Neuroscientist’s Prescription for Improving Your Brain’s Performance'

Read this book Excerpt from 'Think Smart' by Richard Restak.

The greatest enemy to people’s working memory is distraction. If you’re thinking of something else and aren’t really listening when you are told a telephone number the sequence won’t be encoded in your brain. Later, you won’t be able to retrieve it because distraction during the initial encoding process interfered with memory consolidation.

Multitasking, despite its inefficiency, has the potential to strengthen working memory as long as people make a deliberate effort to keep the multiple tasks “in mind.” As the skilled multitasker switches from one activity to another, if he’s adept enough he retains the first activity in working memory. As a result, in contrast to the example of the interruption during the meeting, the skilled multitasker has no problem remembering the point he was about to make just prior to the interruption.

Working-memory deficiencies underlie the distractibility and poor academic achievement of people, adults as well as children, who have attention deficit/hyperactivity disorder (ADHD). Reading problems also result from working-memory problems: the earlier words in a sentence can’t be recalled by the time the reader reaches the end of the sentence.

Many of the classic memory exercises are actually exercises of working memory. Here’s an example of one that I use in my office to test my patients’ working memory: Memorize these four items: apple, charity, Mr. Johnson, tunnel. Now set a chronograph or other timing device for five minutes and return to your reading. When the alarm goes off, recite aloud the four items. To do that you had to keep the items in a kind of suspended animation: available for recall and yet not so much “in mind” that they interfered with your ability to understand the pages that you read before the sounding of the alarm signaling that you should recall the items.

In order to distinguish working memory from memory in general, think of it this way: If you’re required, as in the above example, to hold certain items “in mind” while you turn your attention to something else, you’re using working memory. If you’re simply asked to recall something from the past (“Who was the sixteenth president of the United States?”), that is a test of general memory. Working memory is also called upon whenever we mentally manipulate information. For instance, memorize these numbers: 238538392. Now, as an exercise in working memory, rearrange that sequence from lowest to highest (223335889) without writing anything down.

Reprinted from Think Smart by Richard Restak, M.D., by arrangement with Riverhead, a member of Penguin Group (USA), Inc., Copyright (c) 2009 by Richard Restak.