Sleepyheads’ brains veer from restful path

A good night’s sleep seems to clear the brain and help the well-snoozed individual negotiate the flow of daily affairs.

In contrast, a lack of sleep makes it difficult to carry out even mundane acts, such as conversing intelligibly or calculating a waiter’s tip. Initial investigations of brain activity in sleepy volunteers as they try to perform verbal and mathematical tasks have yielded intriguing clues about the nature of sleep deprivation.