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Medical Specializations


Paediatrics => Epilepsy => Consciousness, Altered States of


Consciousness, Altered States of


Consciousness, Altered States of, different states of awareness that may occur in dreaming, hypnosis, through the use of certain drugs, or, it is said, through the practice of certain forms of meditation and yoga.

Interest in altered states of consciousness has a long history, but after the work of Sigmund Freud and early explorations of hypnosis, the subject declined in the earlier part of the 20th century, reviving with the general interest in the nature of consciousness in the 1950s. Much of the surge in sleep and dream research arose from the discovery of a physiological indicator of the dream state-rapid eye movements. At roughly 90-minute intervals, the eyes of sleepers were observed to move rapidly, and, at the same time, the sleepers' brain waves would show a pattern resembling the waking state. When people were awakened during these periods of rapid eye movement, they almost always reported dreams, whereas if awakened at other times they did not. This and other research clearly indicated that sleep, once considered a passive state, was instead an active state of consciousness.

During the 1960s, an increased search for "higher levels" of consciousness through meditation resulted in a growing interest in the practices of Zen Buddhism and Yoga from Eastern cultures. A full flowering of this movement was seen in the development of training programmes, such as Transcendental Meditation, that were self-directed procedures of physical relaxation and focused attention. Biofeedback techniques were also developed to bring body systems involving factors such as blood pressure or temperature under voluntary control by providing feedback from the body, so that subjects could learn to control their responses. For example, researchers found that people could control their brain-wave patterns to some extent, particularly the so-called alpha rhythms generally associated with a relaxed, meditative state.

Hypnosis involves a transfer of conscious control from the subject to another person. Hypnotism has had a long and controversial history in medicine and folklore and has been intensively studied by psychologists. Much has become known about the hypnotic state, relative to individual suggestibility and personality traits; the subject has now largely been demythologized, and the limitations of the hypnotic state are fairly well known. Despite the increasing use of hypnosis, however, much remains to be learned about this unusual state of focused attention.
Finally, many people in the 1960s experimented with the psychoactive drugs known as hallucinogens, which produce disorders of consciousness. The most prominent of these drugs are: lysergic acid diethylamide, or LSD; mescaline, or Peyote; and psilocybin; the latter two have long been associated with religious ceremonies in various cultures. LSD, because of its radical thought-modifying properties, was initially explored for its so-called mind-expanding potential and for its psychotomimetic effects (imitating psychoses). Little positive use, however, has been found for these drugs, and their use is highly restricted.

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