Rapid eye movement (REM) sleep is a stage of sleep that evolved in part to provide a privileged time in each day when the brain is disconnected from sensory input and freed of intentional, directed thought. The neurochemistry and neurophysiology of the brain during REM sleep is optimized for the exploration of normally ignored connections and associations within the brain’s vast repertoire of...
Abstract: It may be surprising to learn that the brain’s intrinsic, ongoing activity is the dominant mode of brain function, present and largely nonconscious whether we are daydreaming, sleeping, or engaged in the full range of human behaviors. Intrinsic activity is easily seen in the ongoing electrical activity of the brain, where extensive averaging is needed to separate evoked activity from...