Mental states can markedly alter physiologic function. Hypermetabolic physiologic states, with an increased oxygen consumption, accompany anticipated stressful situations. Hypometabolic physiologic changes, other than those occurring during sleep and hibernation, are more difficult to produce. The present investigation describes hypometabolic and other physiologic correlates of a specific technique of meditation know as “transcendental meditation”. Thirty-six subjects were studied, each serving as his own control. During meditation, the respiratory changes consisted of decreased O2 consumption, CO2 elimination, respiratory rate and minute ventilation with no change in respiratory quotient. Arterial blood pH and base excess decreased slightly; interestingly, blood lactate also decreased. Skin resistance markedly increased, while systolic, diastolic, and mean arterial blood pressure, arterial PO2 and PCO2, and rectal temperature remained unchanged. The electroencephalogram showed an increase in intensity of slow alpha waves and occasional theta-wave activity. The physiologic changes during meditation differ from those during sleep, hypnosis, autosuggestion, and characterize a wakeful hypometabolic physiologic state.
