The process of psychic development generally entails learning
to refocus attention from the outer world of sensory input
and directing attention inward in some form. One popular
form is meditation, in which the person consciously withdraws
attention from sensory data. Various attempts to readjust the
environment to reduce sensory input have been made. Lights
can be dimmed, a quiet location selected, a comfortable posture
assumed, and breathing regulated.
The heightened blocking of normal sensory input has been
found to result in hallucinations and vivid fantasies. Such a
heightened blockage can be attained by placing a person in a
sensory neutral environment. In the Ganzfeld setting, the eyes
and ears are covered, and a sensory neutral environment is created
with blue light and white noise.
An even more intense experience is provided by the isolation
tank, in which an individual can float in water at a controlled
temperature in a soundproof, lightproof chamber.
While such experiments may be exhausting and affect mental
process in an unstable individual, they can throw light on personality
disorders and apparent paranormal experiences. An
apparatus called the Witches Cradle, devised by Robert E. L.
Masters and Jean Houston of the Foundation for Mind Research,
has been developed to study heightened sensory deprivation.
Hooper, Judith, and Dick Teresi. Would a Buddha Wear a
Walkman New York Simon & Schuster, 1990.
Solomon, P., and others eds. Sensory Deprivation. Cambridge,
Mass. Harvard University, 1961.