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Approved For Release 200 NPP AGS] FEB FROP96-00788R001300020001-6 ST-CS-01-169-72 July 1972 PART IX SENSORY DEPRIVATION 1. (U) A relatively recent development in experimental psycho- logy has been the study of the effects upon human behavior of a severe reduction in the level and variability of visual, auditory, and tactual-kinesthetic stimulation. The experimental attempts to achieve such a non-changing sensory environment are often referred to by such terms as stimulus deprivation, sensory or perceptual deprivation, or sensory and perceptual isolation. What- ever the terminology, this condition can produce marked behavioral and physiological changes. It has been demonstrated that a varied and patterned sensory environment is essential to the maintenance of normal human behavior. If a person is required to live for many days in a monotonous, non-changing sensory and perceptual environment, his physiological and psychological processes may operate in extraordinary ways (282). 2. (U) The following discussion is excerpted from a report by Zubek (282). According to Zubek, the first experimental work on perceptual deprivation began in 1951 at McGill University. Its purpose was to further the understanding of the mechanisms under- lying "brainwashing" (e.g. Korean War) and of the lapses of atten- tion noted under monotonous environmental conditions, such as- watching a radar screen for a prolonged period of time. The results of the McGill research were very enlightening. The subjects, who were paid to do nothing except lie alone in a semi-sowdproofed chamber for several days, wear translucent goggles and listen to a constant masking sound of low intensity, reported a variety of unusual subjective phenomena e.g. vivid and highly structured hallucinations, delusions, and gross changes in the appearance of the perceptual environment upon emerging from isolation. In addition to these introspective reports, objective test data were obtained which indicated an increased susceptibility to propaganda material, impairments in cognitive and perceptual functioning, and a progressive slowing of occipital alpha fre- quencies with increasing duration of isolation. 3. (U) The results described above, together with several other post-World War II developments, soon started worldwide interest in the effects of sensory isolation and confinement. One source of interest came from the highly publicized "confessions" extracted by communist interrogators (e.g. the Cardinal Mindzenty case). What little information was available suggested that the results were obtained by techniques which often employed solitary confinement 101 UNCLASSIFIED Approved For Release 2003/09/10 : CIA-RDP96-00788R001300020001-6