ACUTE EFFECT OF MUKH BHASTRIKA (A YOGIC BELLOWS TYPE BREATHING) ON REACTION TIME
Ananda Balayogi Bhavanani, Madanmohan* and Kaviraja Udupa
Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education & Research, (JIPMER), Pondicherry - 605 006
Abstract: Reaction time (RT) is an index of the processing ability of central nervous system and a simple means of determining sensory-motor performance. It has been reported that yoga training improves human performance including central neural processing. Earlier studies from our laboratories have shown that yoga training produces a significant decrease in visual reaction time (VRT) and auditory reaction time (ART). The present work was planned to determine if mukh bhastrika (a yogic technique in which breath is actively blasted out in ‘whooshes’ following a deep inspiration) has any effect on central neural processing by studying its effect on RT. 22 healthy schoolboys who were practicing yoga for the past three months were recruited for the present study. VRT and ART were recorded before and after nine rounds of mukh bhastrika. Mukh bhastrika produced a significant (P<0.01) decrease in VRT as well as ART. A decrease in RT indicates an improved sensory-motor performance and enhanced processing ability of central nervous system. This may be due to greater arousal, faster rate of information processing, improved concentration and/ or an ability to ignore extraneous stimuli. This is of applied value in situations requiring faster reactivity such as sports, machine operation, race driving and specialized surgery. It may also be of value to train mentally retarded children and older sports persons who have prolonged RT.
Key words: Mukh bhastrika , reaction time, sensory-motor performance, central neural processing
The physiological and psychological benefits of yoga have been demonstrated in several studies (1, 2, 3, 4). These studies have shown that regular practice of yoga leads to improvement in physiological functions and human performance. Benefits have been reported in both peripheral nerve function (5) as well as central neuronal processing (1, 6, 7). Reaction time (RT) is an indirect index of the processing ability of central nervous system and a simple means of determining sensory-motor association and performance (8). RT involves central neural mechanisms and its study is of physiological interest. It is a sensitive and reproducible test and its measurement can be done with simple apparatus and set up. Determination of RT has important implications in sports physiology (9) and the performance of an athlete is dependent on the duration of RT. It is an index of cortical arousal (6) and a decrease in it indicates an improved sensory motor performance and an enhanced processing ability of the central nervous system. It has been found that changes in breathing period produced by voluntary control of inspiration are significantly correlated to changes in RT (10). Physical conditioning exercises have been shown to shorten visual reaction time (VRT) as well as auditory reaction time (ART) (11). Previous studies on yoga have shown that regular practice of yoga can significantly decrease VRT and ART (1, 6). It has also been suggested that RT can be used as a simple and objective method to determine the beneficial effects of yoga training (1, 6). In an earlier study done in our laboratories, mukh bhastrika, the bellows type breathing was one of the yogic practices performed by the subjects. Mukh bhastrika is a yogic technique in which the breath is actively blasted out in multiple ‘whooshes’ with forced abdominal contractions (12). Agnisar and bhastrika (yogic techniques that employ similar forceful abdominal contractions) have been shown to produce central neuronal activation (13, 14). As mukh bhastrika may have a central activating role, we planned this study to determine the acute effect of mukh bhastrika on VRT and ART. The study was conducted on yoga-trained subjects because they could perform mukh bhastrika properly and readily volunteered for the study.