The Nature of Dream Activity

Dreaming is a form of mental activity, different from waking thought, that occurs during sleep. The nature of dream activity has been characterized by many clinical and laboratory studies. These studies show that dreams are more perceptual than conceptual: Things are seen and heard rather than thought. In terms of the senses, visual experience is present in almost all dreams; auditory experience in 40 to 50 percent; and touch, taste, smell, and pain in a relatively small percentage. A considerable amount of emotion is commonly present—usually a single, stark emotion such as fear, anger, or joy rather than the modulated emotions that occur in the waking state. Most dreams are in the form of interrupted stories, made up partly of memories, with frequent shifts of scene. This broad characterization includes a great variety of dream experiences.

Many dreams collected in sleep laboratories are rather ordinary, but most people have at least some bizarre dreams. At the start of the 20th century Sigmund

Freud proposed that a mental process quite different from that used in the waking state dominates the dreaming mind. He described this “primary process” as characterized by more primitive mechanisms, by rapid shifts in energy and emotions, and by a good deal of sexual and aggressive content derived from childhood. Research in recent years has clarified many of these aspects of dreaming, but what may be of greatest significan...