My APA Paper on Isolation, Sensory Deprivation & Sensory Overload

Originally posted by valtin on 08/29/07

Crossposted at Invictus and NION

The following is the text of a paper I presented on Sunday, August 19, 2007 to an audience of about three hundred at the American Psychological Association (APA) convention in San Francisco, California. It is, in fact, an abstract of a much longer paper now in the final stages of preparation. Its brevity was dictated by the very short time speaking time allowed. I have included my bibliography here for those interested.

As many are no doubt aware, the APA Council of Representatives passed a resolution on psychologist participation in coercive interrogations that was long on rhetoric, but far short on substance. In essence, the APA legitimized psychologist practice in settings where indefinite detention occurs, along with sensory and sleep deprivation, sensory over-stimulation, and use of drugs (as long as not for the purpose of eliciting interrogation).

My paper was written with the intent to document the long history of behavioral science collaboration with abusive interrogation research, particularly around the subject of sensory deprivation (SD). I did not have time in this paper to address the strong observational and naturalistic evidence of the debilitating effects of isolation and SD, and readers will have to await my longer, published paper.

It is also worth noting that the negative effects of SD are powerfully amplified by the overall context of the coercive and abusive environment in the prison or detainee environment. In fact, as regards interrogation or conditions of prisoner incarceration, SD is never used alone, but in combination with other coercive techniques.

Isolation, Sensory Deprivation, and Sensory Overload: An Historical Overview

“The abuse of knowledge causes incredulity.” – Rousseau

The use of isolation and sensory deprivation at U.S. foreign prisons, the detainee facility at Guantanamo Bay, and the Charleston Naval Brig in South Carolina has been well documented. Physicians for Human Rights has an excellent pamphlet called “Break Them Down” that offers an overwhelming amount of documentation. The important thing to understand about the use of psychological torture is that the conditions of detention are inexorably intertwined with the techniques of interrogation.

This presentation is a historical look at the research project that was sensory deprivation, conducted 35-50 years ago, in which psychologists, psychoanalysts, and psychiatrists worked for the CIA and the Pentagon to understand the effects of sensory deprivation, and which ended in making sensory deprivation, and later sensory overload, an integral part of the U.S. coercive interrogation paradigm. One obvious problem with this research is the lack of any controlled experiments upon actual prisoners. A less obvious but even more serious problem concerns lack of access to classified materials and studies, especially given that much of the research was done by intelligence and military entities and kept secret.

The beginnings of concentrated psychological research into the manipulation of sensory and perceptual stimulation began early in the Cold War in the late 1940s-early 1950s. Donald Hebb, a past president of the American Psychological Association and an important theoretician in psychology, was an early researcher into sensory deprivation’s effects upon adult human beings.

Dr. Hebb explained his involvement at a Harvard symposium on sensory deprivation in June 1958.

The work that we have done at McGill University began, actually, with the problem of brainwashing. We were not permitted to say so in the first publishing…. The chief impetus, of course, was the dismay at the kind of “confessions” being produced at the Russian Communist trials. “Brainwashing” was a term that came a little later, applied to Chinese procedures. We did not know what the Russian procedures were, but it seemed that they were producing some peculiar changes of attitude. How?

One possible factor was perceptual isolation and we concentrated on that. (Solomon 1961)

Marks (1979) describes the atmosphere in behavioral and psychiatric research in the 1950s and early 1960s:

Nearly every scientist on the frontiers of brain research found men from secret agencies looking over his shoulders, impinging on the research.

University of Virginia bioethicist Jonathan Moreno, wrote recently (Moreno 2006):

To a great extent, modern psychology and social science were founded on the financial support they received from national intelligence agencies during and after World War II…. These close ties remained after hostilities against the Axis powers ended. In the early 1950s, nearly all federal funding for social science came from the military, and the Office of Naval Research was leading sponsor of psychological research from any source in the immediate postwar years. The CIA found ways to support a large number of Ivy League academics, often without the professors’ knowledge, as its funds were passed through dummy foundations that often gave grants to other foundations. (p. 65)

Besides Hebb’s research at McGill, other centers of extensive research on sensory deprivation during the period under consideration included many U.S. and Canadian sites, including, but not limited to: Princeton University; the National Institute of Mental Health in Bethesda, Maryland; Boston City Hospital and Harvard University; the Naval Medical Research Institute in Bethesda, Maryland; the University of Manitoba; the University of Michigan, Ann Arbor; the Research Center for Mental Health at New York University; Cornell University; various VA hospitals, and many others.

By the mid-1970s, however, there was a steep drop-off in published literature on sensory deprivation. The reason for this is unknown, but could be due to controversies over revelations of these and other programs by the military and CIA (Greenfield 1977). The decline in research is also coincident in time with the cancellation of the CIA’s MKSEARCH program, the successor of MKULTRA, in June 1972.

In any case, the use of isolation and sensory deprivation was continued by U.S. intelligence agencies, as evinced by the CIA’s 1983 Human Resource Exploitation Training Manual (HRETM) (CIA 1983). What follows is a selection of relevant quotes, presented here as giving an intelligence operational view of the effects of sensory deprivation and overload:

The purpose of all coercive techniques is to induce psychological regression in the subject by bringing a superior outside force to bear on his will to resist. Regression is basically a loss of autonomy, a reversion to an earlier behavioral level. As the subject regresses, his learned personality traits fall away in reverse chronological order. He begins to lose the capacity to carry out the highest creative activities, to deal with complex situations, to cope with stressful interpersonal relationships, or to cope with repeated frustrations.  (CIA 1983, p. K-1)

As regards deprivation of sensory stimuli, the CIA training manual explains:

Solitary confinement acts on most persons as a powerful stressor. A person cut off from external stimuli turns his awareness inward and projects his unconsious [sic] outward. The symptoms most commonly produced by solitary confinement are superstition, intense love of any other living thing, perceiving inanimate objects as alive, hallucinations, and delusions…

Deprivation of sensory stimuli induces stress and anxiety. The more complete the deprivation, the more rapidly and deeply the subject is affected…

Some subjects progressively lose touch with reality, focus inwardly, and produce delusions, hallucinations, and other pathological effects. (CIA 1983, pp. K-6, K-7)

The conclusions of the anonymous authors of the CIA manual are congruent with many of the findings of psychological and psychiatric researchers over the previous three to four decades. Princeton psychologist Jack Vernon examined the effects of sensory deprivation and isolation on a group of 18 volunteer graduate students and reported the results in 1958. He found that sensory deprivation had “a significant and essentially deleterious influence upon the subjects”, as measured by tests measuring rotary pursuit ability, color perception, motor coordination, mirror tracing, body weight, and galvanic skin resistance (Solomon 1961). The longer the period of sensory deprivation, the more marked the influence.

In the early research literature, one outstanding feature was the variability of results across experimental conditions. One important and misunderstood variable concerned the presence or absence of hallucinations in different individuals. This variability was due, in part, to a lack of standardization of variables, of controls, of definitions, in addition to personality and neuropsychological factors.

One finding that held across multiple experiments was the susceptibility of the deprivation subject to suggestibility (Solomon, 1961; Zubek 1969; (Hebb 1970). One researcher, Peter Suedfeld, concluded:

Susceptibility to external influence, including both primary suggestibility and persuasibility, is clearly increased by SD. The data indicate that this phenomenon originates with the lack of information anchors in the SD situation: the subject is at loose ends, without guidelines for his behavior, unable to concentrate, and in a state of stimulus- and information-hunger? (Suedfeld 1969, p. 166)

The question of personality variables and their influence upon isolation and deprivation results was tackled early on. Goldberger and Holt (Solomon 1961; Goldberger 1961) found that the ability to handle primary process internal stimuli, as well as other measures of ego-strength, differentiated individuals better able to adapt to sensory deprivation and isolation environments than individuals who scored low on these variables. The government found the influence of personality variables to be very important in planning interrogations, and a large part of psychologist participation in interrogations is related to personality assessment (CIA 1963).

Over the years, researchers discovered other effects of the sensory deprivation situation. One researcher concluded that the evidence was substantial: “both simple and complex measures of visual and motor coordination are adversely affected by sensory and perceptual deprivation” (Zubek 1969). Cognitive tests show “considerable impairment? on unstructured behaviors” (p. 165).

A fairly robust finding was that sensory deprivation increases sensitivity to pain, at least in its initial stages (Solomon 1961). At a symposium held in April 1956 by the Group for the Advancement of Psychiatry, researcher Harold Wolff reported:

We also have reason to believe that the painful experience is one that has a highly symbolic significance and is closely linked with feelings of isolation and rejection, especially when imposed by other human beings under hostile circumstances. (Vernon 1956)

In their paper from the 1958 Harvard symposium, Ruff, Edwin and Thaler (Ruff 1961) described various reactions to reduced sensory input. Examining both military and civilian volunteers at experiments done at Wright-Patterson Air Force Base in Ohio, they described a series of experiments utilizing varying levels of sensory deprivation and conditions of isolation. They found that by the last experiment, in which the conditions allowed the least specific amount of structuring of time duration, communication, or other activities, that a high number of subjects terminated the experiment early, unable to tolerate the conditions of the procedure and displaying “impending or partial breakdown of defenses” (p. 76).

In his article for the book The Manipulation of Human Behavior (Biderman 1961), Lawrence Hinkle, Jr. (1961) described how isolation and sensory deprivation could produce a state of disordered brain function (DBF) similar to that produced by disturbance of brain homeostasis through fever, hypothermia, dehydration, blood abnormalities, shock, hemorrhage, vomiting, and starvation. Individuals with DBF experience thinking difficulties, along with “illusions, delusions, hallucinations, and projective or paranoid thinking” (p. 26).

Hinkle concluded:

It is well known that prisoners, especially if they have not been isolated before, may develop a syndrome similar in most of its features to the “brain syndrome” [see also (Grassian 1983)]… They become dull, apathetic, and in due time they become disoriented and confused; their memories become defective and they experience hallucinations and delusions?. their ability to impart accurate information may be as much impaired as their capacity to resist an interrogator…

From the interrogator’s viewpoint it has seemed to be the ideal way of “breaking down” a prisoner, because, to the unsophisticated, it seems to create precisely the state that the interrogator desires: malleability and the desire to talk, with the added advantage that one can delude himself that he is using no force or coercion?. However, the effect of isolation on the brain function of the prisoner is much like that which occurs if he is beaten, starved, or deprived of sleep.

Hebb (1970) succinctly described the effects at a presentation at the 1970 APA convention: sensory deprivation can produce “an acute disturbance of the normal personality”. It is an “atrocious procedure,” which “raises the whole question of the relation of man to his sensory environment”. Hebb noted, “making the isolation more drastic produces motivational and emotional disturbance more quickly”.

Sensory Overload

While there was for many years a multitude of studies on isolation and sensory deprivation, studies on excessive sensory stimulation were far fewer, and less focused (however, see Lindsley, 1961). Lipowski (1975) conducted a literature review of the research extant some 30 years ago. He reported on some of the work of the Japanese researchers at Tohoku University, whose reports echoed the methodological difficulties of the deprivation researchers in the U.S. Their results, however, were significant.

The Tohoku workers exposed their experimental subjects to intense auditory and visual stimuli presented randomly in a condition of confinement ranging in duration from 3 to 5 hr. The subjects showed heightened and sustained arousal, found sensory overload more aversive than deprivation, and had mood changes in the direction of aggression, anxiety, and sadness. Two subjects reported “hallucinationlike” phenomena. (Lipowski 1975)

Other U.S. researchers have replicated these results. Use of sensory overload has been a technique utilized by SERE schools, and has reportedly been transmitted to use by U.S. military and intelligence interrogators abroad (Streatfeild 2007).

In conclusion, sensory manipulation is well studied; its effects on interrogation have been known for over a generation. The belief that we don’t have enough research on these matters is unfounded. The use of sensory deprivation and overload constitutes torture, is outlawed by international treaties and agreements, and illegal under U.S. law. Active psychologist participation at facilities where it exists constitutes a war crime and should be abandoned immediately.

J—— K—–, Ph.D.

San Francisco, CA

August 19, 2007


Biderman, A. D. Z., Herbert, Eds. (1961). The Manipulation of Human Behavior. New York, John Wiley & Sons.

CIA. (1963). “Kubark Counterintelligence Interrogation.”  Retrieved August 15, 2007, 2007, from….

CIA. (1983). “Human Resource Exploitation Training Manual.”  Retrieved July 30, 2007, from….

Goldberger, L. & Holt, R. R. (1961). A Comparison of Isolation Effects and their Personality Correlates in Two Divergent Samples. New York, Research Center for Mental Health, New York University: 1-52.

Grassian, S. (1983). “Psychopathological effects of solitary confinement.” American Journal of Psychiatry 140: 1450-1454.

Greenfield, P. (1977). CIA’s Behavior Caper. APA Monitor: 1, 10-11.

Hebb, D. O. (1970). “The Motivating Effects of Exteroceptive Stimulation.” American Psychologist 25(4): 328-336.

Lipowski, Z. J. (1975). “Sensory and Information Inputs Overload: Behavioral Effects.” Comprehensive Psychiatry 16(3): 199-221.

Moreno, J. D. (2006). Mind Wars: Brain Research and National Defense. New York Dana Press.

Ruff, G. E. L., Edwin Z.; & Thaler, Victor H. (1961). Factors Influencing Reactions to Reduced Sensory Input. Sensory Deprivation: A Symposium Held at Harvard Medical School. P. Solomon, et al. , Eds. Cambridge, MA, Harvard University Press: 72-90.

Solomon, P., Kubzansky, Philip E., Leiderman, P. Herbert, Mendelson, Jack H., Trumbull, Richard, & Wexler, Donald , Eds. (1961). Sensory Deprivation: A Symposium Held at Harvard Medical School. Cambridge, MA, Harvard University Press.

Streatfeild, D. (2007). Brainwash: The Secret History of Mind Control. New York, Thomas Dunne Books, St. Martin’s Press.

Vernon, J., M. Meltzer, D. Tyler, Weinstein, E. A., Brozek, J., & Woolf, H. (1956). Factors Used to Increase the Susceptibility of Individuals to Forceful Indoctrination: Observations and Experiments. Group for the Advancement of Psychiatry, Asbury Park, NJ, Group for the Advancement of Psychiatry.

Zubek, J. P., Ed. (1969). Sensory Deprivation: Fifteen Years of Research. New York, Appleton-Century-Crofts, educational division.

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One Response to My APA Paper on Isolation, Sensory Deprivation & Sensory Overload

  1. [...] kept in isolation for months on end, you can’t expect them to understand, much less report, that one of the desired effects of isolation is to produce a desire to talk, and to foster a positive feeling toward anyone who would spend time [...]


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