ABSTRACT
BACKGROUND/AIMS: One month of yoga training has been shown to reduce the pulse rate voluntarily without using external cues. Hence, the present study was designed to understand the strategies used by yoga practitioners and autonomic changes associated with voluntary heart rate reduction. MATERIALS AND METHODS: Fifty volunteers (group mean age ± S.D., 25.4 ± 4.8 years; 25 males) were assessed in two trials on separate days. Each trial was for 12 minutes, with a 'pre' state and 'during' state of 6 minutes each. For both trials the 'pre' state was relaxation with eyes closed. In the 'during' state of Trial I, subjects were asked to voluntarily reduce their heart rate using a strategy of their choice. From their responses to specific questions it was determined that 22 out of 50 persons used breath regulation as a strategy. Hence, in the 'during' state of Trial II, subjects were asked to voluntarily reduce their heart rate by breath regulation. RESULTS: In the first trial, the heart rate was reduced by an average of 19.6 beats per minute and in the second trial (with breath regulation exclusively) an average decrease of 22.2 beats per minute was achieved. CONCLUSIONS: Hence, the strategy used did not markedly alter the outcome.
ABSTRACT
CONTEXT: Practicing mental repetition of "OM" has been shown to cause significant changes in the middle latency auditory-evoked potentials, which suggests that it facilitates the neural activity at the mesencephalic or diencephalic levels. AIMS: The aim of the study was to study the brainstem auditory-evoked potentials (BAEP) in two meditation states based on consciousness, viz. dharana, and dhyana. MATERIALS AND METHODS: Thirty subjects were selected, with ages ranging from 20 to 55 years (M=29.1; ±SD=6.5 years) who had a minimum of 6 months experience in meditating "OM". Each subject was assessed in four sessions, i.e. two meditation and two control sessions. The two control sessions were: (i) ekagrata, i.e. single-topic lecture on meditation and (ii) cancalata, i.e. non-targeted thinking. The two meditation sessions were: (i) dharana, i.e. focusing on the symbol "OM" and (ii) dhyana, i.e. effortless single-thought state "OM". All four sessions were recorded on four different days and consisted of three states, i.e. pre, during and post. RESULTS: The present results showed that the wave V peak latency significantly increased in cancalata, ekagrata and dharana, but no change occurred during the dhyana session. CONCLUSIONS: These results suggested that information transmission along the auditory pathway is delayed during cancalata, ekagrata and dharana, but there is no change during dhyana. It may be said that auditory information transmission was delayed at the inferior collicular level as the wave V corresponds to the tectum.
ABSTRACT
BACKGROUND: In Indian scriptures the sacred syllable Om is the primordial sound from which all other sounds and creation emerge which signifies the Supreme Power. AIMS: To explore the significance of the syllable OM from ancient texts and effects of OM meditation in contemporary science. DESCRIPTIONS FROM ANCIENT TEXTS: The descriptions of Om have been taken from four Upanisads (Mundaka, Mandukya, Svetasvatara, and Katha), the Bhagvad Gita, and Patanjali's Yoga Sutras. SCIENTIFIC STUDIES ON OM: Autonomic and respiratory studies suggest that there is a combination of mental alertness with physiological rest during the practice of Om meditation. Evoked potentials studies suggest a decrease in sensory transmission time at the level of the auditory association cortices, along with recruitment of more neurons at mesencephalic-diencephalic levels. CONCLUSIONS: It is considered that a person who realizes Om, merges with the Absolute. Scientific studies on Om suggest that the mental repetition of Om results in physiological alertness, and increased sensitivity to sensory transmission.
