Physiology of mediation: a review, a wakeful hypometabolic interrated response

While for centuries a wakeful and tranquil state or experience variously called 'samadhi,' 'pure awareness,' or 'enlightenment' had been said to be a normal experience and the goal of mediation in Vedic, Buddhist, and Taoist traditions, there was little known about this behaviou until recently, when the practice of 'transcendental mediation' (TM) became available for study in Western scientific laboratories. Derived from the Vedic tradition, TM is unique because it requires no special circumstances or effort for practice. Based upon a wide spectrum of physiological data on TM, we hypothesize that meditation is an intergrated response with peripheral circulatory and metabolic changes subserving increased central nervous activity. Consistent with the subjective description of mediation as a very relaxed but, at the same time, a very alert state, it is likely that such findings during meditaion as increased cardiac output, proable increased cerebral blood flow, and findings reminscent of the 'extraordinary' character of classical reports: apparent cessation of CO2 generation by muscle, fivefold plasma AVP elevation, and EEG synchrony play critical roles in this putative state.