Tantra or yoga. Clinical studies, section 3: comparative paper

Several clinical studies show how tantric practices and exercises of Vedic traditions - such as yoga- or Theravada or Mahayana Buddhists - have a significant psychobiological impact. This study compares the neurophysiological correlates of the practices called tantric and non-tantric meditations by a qualitative systematic review of the data collected. It was evidenced that the tantric practices produce increase in the sympathetic activity, the state of "phasic alertness" and in the performance in visual cognitive tasks. They promote greater alertness and lower propensity to sleep, generate an increase in cognitive activity and metabolic modifications contrary to those that are verified of non-tantric as a result of the relaxation induced by these practices. In contrast, non-tantric creams create a better relaxation response with increased parasympathetic activity and inhibition of the sympathetic system, inducing a deep rest hypometabolic state where the practitioner remains awake and his attention on "tonic alertness" with corresponding symptoms to that hypometabolic state -hypotonia, decreased oxygen consumption, heart rate and blood lactate concentration- change in normal endocrine function, increased phenylalanine concentration in advanced meditators, increased plasma prolactin levels, a five-fold increase in arginine vasopressin plasma levels, while thyroid stimulating hormone decreases chronically and acutely. This neurophysiological difference corresponds to the differences found in the investigated texts which point out that: the tantric ones aim to increase alertness or an awakened quality of the mind and warn against excessive calm and on the contrary, the writings and instructions of meditation of the Vedic tradition, yoga, Theravada or Mahayana aim to achieve stillness and calmness. We indicate future clinical research from a more interdisciplinary approach and incorporating the theoretical / philosophical framework of the different types of meditation.