Sensory Deprivation

Other applications have grown out of research on altered states of consciousness
produced by restricting sensory stimulation from the environment.
Researchers in the 1950’s completed extensive studies on the effects
of prolonged sensory deprivation. Subjects placed in soundproof isolation
chambers with translucent goggles to eliminate vision and padded arm tubes to minimize touch sensation often experienced negative psychological
effects after about a day. Most subjects suffered from extreme boredom,
slowed reaction time, and impaired problem-solving ability. Some subjects
reacted to sensory deprivation by creating their own internally generated
sights and sounds in the form of hallucinations. These results led to the institution
of special procedures to help reduce the effects of sensory deprivation
in certain occupations; for example, airline pilots on long night flights,
astronauts living for prolonged periods in tiny space capsules, and individuals
working in isolated weather stations. A controlled form of sensory deprivation,
known as restricted environmental stimulation therapy (REST), has
been used to reduce the effects of overarousal and hyperactivity. REST sessions
usually involve floating in heavily salted warm water in a dark, soundproof
tank. Most subjects find this floating sensation very pleasant, and
there have been many reports of long-term reductions in high blood pressure
and other stress-related problems.