automatism /ôtom″ətiz′əm/ [Gk, automatismos, self-action] , 1. (in physiology) involuntary function of an organ system independent of apparent external stimuli, such as the beating of the heart, or dependent on external stimuli but not consciously controlled, such as the dilation of the pupil of the eye. 2. (in philosophy) the theory that the body acts as a machine and that the mind, whose processes depend solely on brain activity, is a noncontrolling adjunct of the body. 3. (in psychology) mechanical, repetitive, and undirected behavior that is not consciously controlled, as seen in psychomotor epilepsy, hysterical states, and such acts as sleepwalking. Also called automatic behavior. Kinds include ambulatory automatism, command automatism, immediate posttraumatic automatism.
