The Effects of Sleep Deprivation

Sleep restores the body and the mind and helps prevent disease by strengthening the immune system. However, many adults do not get the recommended eight hours of sleep each night. The average adult today gets only 6.4 hours of sleep, nearly an hour and a half less than what the average person received a century ago. Only in recent years have health professionals begun to realize the prevalence and severity of sleep deprivation in the working population. A significant number of people work at night, work long shifts, or suffer from insomnia or jet lag. Others are deprived of sleep because they work too hard, stay out too late, or try to do too many things in a day. Adults who regularly sleep six hours or less might think they accomplish more by staying up late, but they pay for it the next day when they feel sleepy or irritable or are unable to concentrate, remember things, or be very effective at their work.

Studies show that the brain is adversely affected by sleep deprivation because certain patterns of electrical and chemical activity that occur during sleep are interrupted and the brain cannot function normally. In one study, thirteen healthy adult subjects who usually had normal sleep patterns were kept awake and carefully monitored in a hospital sleep laboratory during a period of 35 hours. During the experiment, the subjects were asked to perform several cognitive tasks, such as arithmetic and word problems, while undergoing magnetic resonance scans of their brain activity. The scans recorded each subject’s brain activity from a rested state through various stages of sleep deprivation over the 35-hour period. The scans produced images showing increased activity in some regions of the brain and decreased activity in others. The researchers found that the temporal lobe of the brain, the region involved in language processing, was activated during verbal tasks in rested subjects but not in sleep-deprived subjects. When subjects were fully rested, their magnetic resonance scans showed that the temporal lobe was very active. However, after several hours without sleep, there was no activity within this region. The effects of the inactivity included slurred speech in the subjects who had gone for prolonged periods with no sleep.

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