It began with a swim in the ocean. Suddenly Jessica realized that she had gone much farther away from shore than she expected and, to her great dismay, there was a pair of killer whales swimming toward her. The whales circled around her several times while she did her best not to panic. After several minutes of playful dives and underwater acrobatics, the whales swam away just as suddenly as they had appeared. What happened next was terrifying. The ocean swelled up, curled over, and slammed Jessica back onto the beach.
That’s when she woke up. This dream report is just one of the myriad bizarre scenarios that people perceive to happen to them while they sleep. Some people describe specific elements in their dreams that they can trace directly to things they have recently seen, heard or experienced, as though their minds are attempting to organize bits and pieces of information gathered during waking hours. Dreamers note repeated themes; the dreamer in this case is a woman who has recurring dreams that take place in or near the ocean. She has been recording these dreams for years in a dream diary, hoping to some day sort out the meaning of such fantastic imaginings that occupy her mind while she sleeps.
Since the earliest of recorded histories, people have theorized about the function and meaning of dreams. Answers came largely from the spirit world until Aristotle and Plato developed the drive related hypothesis that was later expanded on by the European psychoanalysts of the 19th and 20th centuries. This hypothesis defines dreaming as a way to act out unconscious desires in a safe or “unreal” setting, presumably because to do so in reality would be unacceptable or even detrimental. But even in the 21st century we still are not sure why we dream. The only way to study dreams is to ask the dreamer. However, one thing we know for sure is that dreaming is something that the vast majority of humans do every night of their lives.
In 1953 Eugene Aserinsky, a graduate student in physiology, and Nathaniel Kleitman, PhD, chair of physiology at the University of Chicago, discovered the phenomenon of rapid eye movement (REM) during a series of sleep studies. Study participants who were awakened during REM sleep invariably recalled bizarre and vivid dreams. If awakened while eyes were motionless (non-REM sleep), participants rarely recalled dreaming. Before the REM discovery, most scientists believed that the brain was essentially inactive during sleep. The Chicago researchers proved that the brain is indeed active during sleep, a finding that helped establish the sleep science discipline, which has led to the diagnosis and treatment of 84 known or suspected sleep disorders.
A few years after the REM discovery, Michel Jouvet, MD, of Claude Bernard University in Lyon, France, recognized that brain activity during REM sleep resembles that of wakefulness. He called REM “paradoxical sleep” because of the fact that such cognitive activity is accompanied by muscular paralysis. He referred to non-REM sleep, a time of reduced brain activation, as “quiet sleep,” in which there is no muscular inhibition.
In a pioneering study conducted by William C. Dement, MD, PhD, in 1960, the psychological effects of REM deprivation were discovered by waking subjects just as they began dreaming. Dr. Dement observed increased tension, anxiety and irritability among his subjects along with difficulty concentrating, an increase in appetite with consequent weight gain, lack of motor coordination, feelings of emptiness and depersonalization and hallucinatory tendencies. The results of this study clearly indicate that dreaming has profound importance and that dream deprivation can have very serious consequences.
But even with these discoveries, the question of why we dream remains unanswered. Some researchers think dreaming might have evolved for physiological reasons. There is a great deal of neuronal activity occurring while we sleep, especially in REM, and it has been suggested that dreams may just be a meaningless by-product of this biological function. Another theory of dreaming is put forth by Rosalind Cartwright, PhD, Professor and Chairman, Department of Psychology at Rush University Medical Center in Chicago. Dr. Cartwright believes that dreams are the mechanism whereby the brain incorporates memories, solves problems and deals with emotions. In this way, she maintains, dreams are essential for our emotional health.
In spite of our attempts to demystify the phenomenon of dreaming, human beings simply have not yet come close to answering the question “Why do we dream?” According to Jim Pagel, MD, Director of the Sleep Disorders Center of Southern Colorado, “If dreaming has an actual function, it really supports why we spend a third of our lives sleeping.” For now, we will have to be content with simply enjoying the show our brain puts on for us each night.