Introduction Sensory deprivation, a new area of investigation in psychology and psychiatry,1has long been familiar to students of certain types of literature. Autobiographical reports from explorers and shipwrecked sailors2-5have indicated that gross mental abnormalities such as hallucinations, delusions, and disorientation can occur in persons who are isolated for any length of time. More recently,6during the Korean conflict, the effect of sensory deprivation was observed in American prisoners of war who were placed in a highly controlled environment, impoverished of sensory stimuli. Experimental Studies The experimental study of sensory deprivation was begun by the psychologists Bexton, Heron, and Scott,7in Hebb's Laboratory at McGill University in 1953. These investigators were concerned originally with the practical problem of "lapses in attention" which occur when a man must perform monotonous repetitive acts over a long period of time. In their study, using 22 college men, they