Unlike previously reported meditation studies of early 1970's, in this empirical study the proficient meditators demonstrated increased autonomic activation during meditation while inexperienced meditators demonstrated autonomic relaxation.During meditation, proficient meditators demonstrated increased alpha and theta power,minimal evidence of EEG defined sleep, and decreased autonomic orienting to external; stimulation.An episode of sudden autonomic activation was observed which was characterized by the meditator as an approach to the Yogic ecstatic state of intense concentration. These findings challenge the current "relaxation" model of meditative states.