DISCUSSION

The CFF depends on a variety of factors, such as stimulus characteristics, concurrent stimulation of other sensory modalities, temperature, body position, and diurnal rhythms (Graham, 1965). In the present experiment stimulus parameters were kept constant. Also other sensations were cut-off by carrying out both initial and final tests under constant illumination and in a sound-attenuated room, with temperature maintained constant, and the subject seated in a comfortable position. The time of testing was also kept the same. Other factors which influence CFF are the levels of concentration, attention, and relaxation. These factors could have influenced the CFF favorably in the present study. Apart from this, temporal resolution of visual stimuli is often limited by the brain rather than the eye (Riggs, 1992). The improvement could be related to enhanced neural processing at the thalamic level which occurs during pranayama and meditation (Telles et al. 1992, Telles et al., in press).

Hence the significantly higher CFF levels seen after 10 days of yoga training could be due to diverse factors, ranging from more efficient processing of sensory information in the brain to increased attention, concentration, and simultaneous relaxation with yoga.