Module 9 Introduction

Sleep and Dreams

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9-1 What is sleep?

SLEEP—THE IRRESISTIBLE TEMPTER TO whom we inevitably succumb. Sleep—the equalizer of presidents and peasants. Sleep—sweet, renewing, mysterious sleep. While sleeping, you may feel “dead to the world,” but you are not. Even when you are deeply asleep, your perceptual window is open a crack. You move around on your bed, but you manage not to fall out. The occasional roar of passing vehicles may leave your deep sleep undisturbed, but a baby’s cry interrupts it. So does the sound of your name. EEG recordings confirm that the brain’s auditory cortex responds to sound stimuli even during sleep (Kutas, 1990). And when you sleep, as when awake, you process most information outside your conscious awareness.

Many of sleep’s mysteries are being solved as some people sleep, attached to recording devices, while others observe. By recording brain waves and muscle movements, and by observing and occasionally waking sleepers, researchers are glimpsing things that a thousand years of common sense never told us. Perhaps you can anticipate some of their discoveries. Are the following statements true or false?

“I love to sleep. Do you? Isn’t it great? It really is the best of both worlds. You get to be alive and unconscious.”

Comedian Rita Rudner, 1993

  1. When people dream of performing some activity, their limbs often move in concert with the dream.
  2. Older adults sleep more than young adults.
  3. Sleepwalkers are acting out their dreams.
  4. Sleep experts recommend treating insomnia with an occasional sleeping pill.
  5. Some people dream every night; others seldom dream.

All these statements (adapted from Palladino & Carducci, 1983) are false. To see why, read on.