Abstract
‘What is dreaming?’ examines what causes dreaming, and discusses why dreams are so strange and hard to remember. Dreaming is most usefully defined and measured through perceptual, cognitive, and emotional qualities: its formal features rather than its content. Data reports show selective activation of brain circuits underlying emotion and related percepts in rapid eye movement (REM) sleep. Meanwhile, selective inactivation of brain circuits and chemicals explain the cardinal cognitive features of dreaming: loss of awareness of self (self-reflective awareness); loss of orientational stability; loss of directed thought; reduction in logical reasoning; and, last but not least, poor memory both within and after the dream.