Summary & Conclusion :
In this stratified randomized controlled study on 614 school children (9-17years) , who practiced three different yoga modules, it has been found that the group which practiced the yoga module for improving the intelligence was significant difference than the module for creativity and physical stamina on their attention and concentration ( on digit cancellation score). All three groups showed improvement in digit, letter and character cancellation.
Uni-nostril yoga breathing through a particular nostril has shown to have significant lateralized effect (3). While designing the IQ module this concept was considered and hence these children were given specific module of right nostril breathing Pranayama with the hypothesis that this would activate the left hemisphere which is necessary for intellectual abilities including attention and concentration. As expected the right nostril breathing (SAV) may have influenced the left brain function which could have increase digit cancellation in IQ group.
The over all improvement in all three groups in digit, letter and character cancellation shows the expected effect, which is indicative of beneficial effect of different yoga modules. The task of cancellation requires sustained visual attention, scanning without distraction and better concentration (7).It is known that reduced anxiety can improve the performance of such tasks requiring attention, learning and memory (8). The anxiety-reducing effects of yoga practice, which are already known (9) could have facilitated in improving attention and concentration. Biofeedback induced relaxation training on sixteen learning disabled children showed significantly fewer numbers of errors in the attention task and significantly lower impulsive score compared to control group (5). Self-instruction and relaxation training showed significant change in attentive behavior of learning disabled children on a cognitive task (10). Drawing evidence from these previous findings, it may be tentatively concluded that significant improvement in cancellation score (digit, letter and character scoring) could be attributed to the relaxation effect of yoga. In all three-cancellation tests, there was less degree of changes in letter cancellation test, it could be due to the fact that letter cancellation is more complex than digit and character cancellation (11).
Limitation of study is wide age range. Long term follow up study is required in real life situation and environment.