Forced single-nostril breathing and cognition.

This experiment investigated whether forced single-nostril breathing differentially affects cognitive abilities presumed to be mediated by the left and right cerebral hemispheres. Phase I was an attempted replication of a reported sex difference in the effects of unilateral breathing on verbal versus spatial performance and Phase II was a study of breathing effects on different verbal and spatial tests. No differences associated with breathing condition were found in the replication study. In Phase II, men breathing through the right nostril scored significantly lower than men in the control condition on a letter-matching test although they did not differ significantly from men in the left-nostril condition on that test. There were no significant breathing-related differences on two spatial tests, and no differences associated with breathing condition for the women. Assessment of nostril dominance before and after cognitive testing showed that the forced-breathing exercise did not significantly alter subjects' nostril dominance. A significant left-nostril bias was found in this sample.