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sensory deprivation n.
The reduction or absence of usual external stimuli or perceptual opportunities, commonly resulting in psychological distress and sometimes in unpleasant hallucinations.
A natural or experimentally arranged situation in which stimulation of a subject's senses is greatly reduced. Experiments have included floating subjects in soundproof water chambers. Though short periods of sensory deprivation can be relaxing, extended deprivation can result in extreme anxiety, hallucinations, bizarre thoughts, depression, and antisocial behavior. Sensory deprivation experiments have demonstrated that humans need constant sensory contact with their environment in order to function.