IMPROVEMENT IN VISUAL PERCEPTUAL SENSITIVITY IN CHILDREN FOLLOWING YOGA TRAINING Manjunath, N.K. and Shirley Telles Vivekananda Kendra Yoga Research Foundation, Bangalore, India.
A sample of 14 children with ages ranging from 12 to 17 years (6 females) who received 10 days of yoga training and another 14 age and sex matched controls who did not receive yoga training were assessed on Day 1 and Day 10 for visual perceptual sensitivity through Critical Flicker Fusion Frequency (CFF) and degree of illusion. Yoga group practised yogasanas, pranayama, kriyas, meditation and bhajans along with specially designed games to improve memory and attention. The control group carried on with their routine Activity. Following 10 days of yoga training, yoga group showed a significant increase in CFF (9.2%) and decrease in degree of illusion (24.89% for in trails and 31.05% for out trails), while the control group showed no change. Thus the present study suggests that younger subjects can show better improvement in performance in a relatively short duration as compared to previous reports. Meditation has been shown to bring about significant changes in perception, attention and cognition (Brown, 1977). That yoga practice increases visual perceptual sensitivity, has been experimentally proved using different methods of assessment. Meditators were found to be more sensitive to, subtle aspects of color and shading of the Rorschach test inkblots than they had been before meditation (Brown, 1980). Two separate studies on Critical Flicker Fusion Frequency (the frequency at which a flickering stimulus is perceived to be steady, with higher values suggesting greater perceptual accuracy) have shown that perceptual sensitivity is not restricted to subtle aspects of the stimulus alone, as detection of a high frequency flickering stimulus was found to improve following yoga training (Ramana et al., 1997; Telles at al., 1995). A study on degree of visual geometric illusions, based on the Muller-Lyer apparatus suggested that a combination of focusing and defocusing through yoga reduces optical illusion more than focusing alone (Telles et al., 1997). These studies were conducted on adult subjects with varying durations of yoga training. Hence the present study was planned to assess visual perceptual sensitivity to Critical Flicker Fusion Frequency and degree of optical illusion in children following 10 days of yoga training.