Studies in the effect of lysergic acid diethylamide (LSD-25): self- and object-size perception in schizophrenics and normal adults.

This study is one of a series of experiments designed to inquire into some of the perceptual effects of administration of lysergic acid diethylamide (LSD-25)* to schizophrenics and normal adults. Specifically, the study deals with the effect of LSD on size perception of one's own body and objects in space. This problem is approached within the framework of organismic behavior theory, viz., the sensory-tonic field theory of perception and the developmental theory. According to the sensory-tonic theory, perception is an experience that corresponds to a particular relation between the organismic state and the impinging stimulus. From this general formulation it follows that a change in either the external stimuli or the organismic state will produce a change in perception. That alterations in organismic state produced by LSD are reflected by changes in perception has been demonstrated by us in another experiment, concerned with perception of verticality (with the same groups