The Stuff of Dreams

A model of dreaming is developed along the following lines: A primary function of the brain is to predict and control environmental events. In order to do so, it constructs a model of the world. The waking brain bases its model primarily on current sensory information, and secondarily on contextual and historical information. In contrast, because the sleeping brain acquires little information from the senses, sources of information that are secondary in the waking state become predominant in the sleeping state. I believe dreams result from the sleeping brain using internal information (memories, expectations, fears, desires, etc.) to create a simulation of the world. According to this theory, dreaming is the result of the same perceptual and mental processes that we use to comprehend the world when awake. From this perspective, to perceive is to dream, or more precisely, perception is dreaming constrained by sensory information; dreaming is perception independent of sensory input, and thus external constraints. Data is presented indicating that typical dreaming and waking experience are less distinct than often assumed, but that dreaming exhibits a wider range of qualities of consciousness than the normal waking state.