Neuro-electric And Behavioral Differences Between Yoga Practitioners And Novices During A Cognitive Control Task

Abstract

The practice of yoga has grown from a spiritual and meditation based discipline to a popular physical activity regimen. PURPOSE: The purpose of this study was to observe the chronic effects of yoga practice on cognitive function through the use of EEG and computerized executive function tasks. METHODS: A total of 21 healthy, right-handed adults (18-25 years old) were recruited for this study. Subjects were divided into novice practitioners (N=11) and advanced practitioners (N=10), with at least two years of experience. EEG and behavioral outcomes were recorded while subjects performed a modified flanker task, requiring them to respond to the direction of the central arrow in an array of five. The flanking arrows either pointed in the same direction (congruent, e.g. > > > > >), or in the opposite direction (incongruent, e.g < < > < <). Accuracy and reaction time were evaluated, alongside N1 and P3 event-related potentials (ERPs). RESULTS: Apart from yoga experience, there were no demographic differences between groups. On the cognitive behavioral task, there was a main effect of congruency on accuracy (F(1,19)=31.99, p<0.001, η2=0.63). All subjects, regardless of group, responded more accurately on congruent trials (98±0.5%) than on incongruent trials (87.5±0.2%). There were also main effects of congruency (F(1,19)=121.14, p<0.001, η2=0.86) and group (F(1,19)=6.28, p=0.021, η2=0.625) on reaction time. Subjects reacted more quickly to congruent trials (404±11.12ms) than to incongruent trials (469±12.37ms). Yoga experts were able to respond more quickly (408±16.48ms) to all stimuli than novices (465±15.71ms). The results of ERP analysis were unclear, and will continue to be studied. CONCLUSIONS: This study provides evidence that regular and prolonged yoga practice improves motor performance on cognitive tasks, implying that yoga practice may provide cognitive benefits. Our EEG data must be studied further to identify the mechanisms behind these benefits. It is possible that the expert group in this experiment was more aerobically fit than the novice group, and that the better motor performance may be due to neuromuscular factors. Future research should focus on identifying the mechanisms of improvement, as well as comparing benefits associated with yoga to those achieved with more conventional physical activity.