An altered state of consciousness is a state of consciousness that differs significantly from baseline or normal consciousness often identified with a brain state that differs significantly from the brain state at baseline or normal consciousness. However, it is not the brain state itself that constitutes an ASC. The brain state is an objective matter, but it should not be equated with an EEG or MRI reading. Otherwise, we would end up counting such things as sneezing, coughing, sleeping, being in a coma, thinking of the color red, and being dead as ASCs. Brain state readings reveal brain activity or inactivity, but are not a good measure of ASCs. Alpha waves, for example, have been identified with an ASC, but they usually measure lack of visual processing and lack of focus, though sometimes they measure a state known as "the Zone" or "the Flow State." This latter state is experienced by some athletes and video-game players who go on "auto-pilot."*

The baseline brain state might be best defined by the presence of two important subjective characteristics: the psychological sense of a self at the center of one’s perception and a sense that this self is identified with one’s body. States of consciousness where one loses the sense of identity with one’s body or with one’s perceptions are definitely ASCs. Such states may be spontaneously achieved, instigated by such things as trauma, sleep disturbance, sensory deprivation or sensory overload, neurochemical imbalance, epileptic seizure, or fever. They may also be induced by social behavior, such as frenzied dancing or chanting. Finally, they may be induced by electrically stimulating parts of the brain or by ingesting psychotropic drugs.

Many think the hypnotic state is an ASC. It certainly often resembles one, but it is doubtful that it is truly an ASC. A hypnotized person closely resembles certain amnesiacs who can be primed by being shown certain words. Later they have no conscious recollection of having been shown the words but they give evidence of implicit memory of the words. It is doubtful that amnesia should be considered an ASC.

There is little evidence that ASCs can transport one into a transcendent realm of higher consciousness or truth, as parapsychologists Charles Tart and Raymond Moody maintain, but there is ample evidence that some ASCs bring about extremely pleasant feelings and can profoundly affect personality. Some religious experiences, for example, are described as providing a very pleasant sense of divine presence and of the oneness, interrelatedness, and significance of all things. Drugs such as LSD and mescaline can induce similar feelings. Some patients suffering from temporal lobe epilepsy think of their disease as temporal lobe “ecstasy,” since it leaves them with a feeling of being united with God (Ramachandran 1998). Also, by electrically stimulating the temporal lobes, Michael Persinger has been able to duplicate the sense of presence, the sense of leaving the body, and other feelings associated with mysticism and alien abduction (Persinger 1987). Dr. Olaf Blanke of Geneva University Hospital in Switzerland found that electrically stimulating the right angular gyrus (located at the juncture of the temporal and parietal lobes) triggers out-of-body experiences.* However, Pehr Granqvist of Uppsala University found that exposing the temporal lobes to weak magnetic fields had no discernable effects.* (In a related matter, Dr. Stuart Meloy, an anesthesiologist and pain specialist in Winston-Salem, North Carolina, was testing his pain-relieving invention on a patient when he accidentally discovered that by electrically stimulating a woman’s spinal column he could induce orgasm.)

Are the brain states that elicit the feelings of mysticism in the religious ecstatic, the epileptic, the one on an “acid” trip, and the one with electrodes attached to his cranium caused by God? Perhaps, but if so there is no way of finding this out. Most likely, however, the mechanisms that trigger these feelings are completely natural. They may be a pleasant side effect of some evolutionary adaptation, but as yet we do not know why such brain states are triggered. And while it is an extremely interesting discovery that religious experiences can be induced by disease, electrodes, and by drugs, it hardly seems a compelling reason for believing in God. Although it might be a compelling reason for taking drugs, for not seeking treatment, or for using a transcranial electromagnetic stimulator and hoping for Orgasmatron results like the Woody Allen character in “Sleeper.” Most religions identify the ideal state as an ASC: losing one’s body and one’s self, uniting with some sort of Divine Being, and feeling ecstatic pleasure. In this sense, to seek an ASC is to seek to kill your sense of self while enjoying the ultimate orgasm.