In
psychology, a
stimulus is an energy change (such as light or sound) which is registered by the senses. In
behaviorism and related
stimulus–response theories, a stimulus constitutes the basis for
behavior, whereas it constitutes the basis for
perception in
perceptual psychology. In this context, a distinction is made between the
distal stimulus (the external, perceived object) and the
proximal stimulus (the stimulation of sensory organs).