somewhat bizarre story. Even those people who claimed to rarely dream or only remember fragments of dreams in the mornings were able to give detailed accounts of a true dream experience when awakened during REM sleep. Those who were awakened during SLOW-WAVE sleep (the deeper, less mentally active stages of sleep) reported mental activity in only about 60% of cases. Usually, this activity lacked the vivid sensory and motor hallucinations of true dreams. This type of mental activity is called SLEEP THOUGHT, and usually pertains to what the person had been thinking about most of the day. However this thought is usually much less productive than that of conscious thoughts (while the person is awake). Those who believe that we dream due to the brain's regular exercise of groups of neurons cite evidence that synapses can degenerate if they go too long without being active; this neural activity during REM sleep helps to preserve important neural pathways. When neurons in the motor and perceptual regions of the brain are exercised in this manner, the inevitable side-effect are the dreams we experience. The increased mental thought activity is due to the sleep thought being engaged in trying to make sense of these movements and hallucinations. ...
