An
altered state of consciousness (
ASC), also called
altered state of mind or
mind alteration, is any condition which is significantly different from a normal waking
beta wave state. The expression was used as early as 1966 by Arnold M. Ludwig and brought into common usage from 1969 by
Charles Tart. It describes induced changes in one's mental state, almost always temporary. A synonymous phrase is "altered state of awareness".