Chapter 1. Sleep: Why We Sleep

Short Description

Why do we sleep? What happens during sleep that is so important that we spend approximately one-third of our adult life doing it

Long Description

Why do we sleep? What happens during sleep that is so important that we spend approximately one-third of our adult life doing it? Does sleep serve one primary function or many related functions?

One way scientists explore these questions is by conducting studies to examine the outcomes of sleep deprivation. These studies have proven that sleep deprivation leads to weakened immune function, negative moods, and decreases in performance on attention and memory tasks. Robert Stickgold points out that brain imaging technology allows us to understand the role of sleep in memory processing. One primary function of sleep is to allow time for our brains to process information from our waking life.

The program then moves into a discussion on the five stages of sleep. Use of the electroencephalogram (EEG) allows researchers to measure and record changes in the electrical activity of the brain during the various stages of sleep. Sleep consists of two basic states: rapid-eye movement (REM) sleep and non-rapid eye movement (NREM) sleep, which is made up of four stages. The entire sleep cycle, the progression from stages one to four, to REM, and back to stage one, takes approximately 45 minutes to an hour to complete. Stickgold describes what happens in each sleep stage before bringing up the topic of dreams. What we dream about, says Stickgold, typically has some connection to our lives.

Researchers today tend to rely on the activation-synthesis model to explain how dreams are formed. This theory suggests that dreaming is the result of various parts of the brain—those involved with memory, emotions, and sensations—being activated. Essentially, dreaming allows the brain to organize and consolidate information to make space for more.

Sleep serves both medical and psychological functions and is essential to the regeneration of the brain and body's systems. The amount of sleep one should get varies by age and individual needs. Sleep disorders, like insomnia, can negatively impact our overall health.

Questions