Dreams and the Dreaming Brain

Abstract

Abstract The neuroanatomy and physiology of dreams and transitional states of sleep as well as functions of dreams are described. The major types of dreams such as lucid dreaming, daydreaming, and nightmares are discussed. Modern research suggests that sleep is a well-organized activity. The sleeping brain remains active and dreaming occurs in rapid eye movement (REM) sleep periods as well as in non-REM sleep. The “dreaming machine” involves large areas of the brain, and fMRI studies reveal complex patterns of activation and inhibition of multiple cortical and subcortical brain regions. Cerebral areas producing images are turned on, which explains the visual nature of dreams. Brain areas responsible for placing objects in their physical context remain inhibited, explaining why proportions are often distorted in dreams. It is suggested that the “primary driving forces of dreaming” are found in the meso-cortico-limbic system. This circuit is implicated in emotion and reward processing. Studies show that dopaminergic modulation plays an important function in dreaming. Dreaming can be considered as an important form of feeling and thinking. In dreams the most unexpected associations happen and both logical and illogical contents are featured. Dreams offer many facets such as problem solving, creative ideas, and new insight into personal functioning. They deal with emotional regulation, represent social interactions, and lead to better self-knowledge. While dreaming the body is active, feels intensively, and has even more abilities than the awake body, for example, it can fly. In psychotherapy dream narratives allow images to be connected with emotions and a search for meaning. During or after traumatic experiences, nightmares may or may not replay the dramatic events: accompanying violent emotions may gradually change into less overwhelming feelings, a process necessary to prevent their recurrence. Dreaming can then been regarded as having a restitutive function.