Effect of forced unilateral nostril breathing on blink rates: relevance to hemispheric lateralization of dopamine.

The involuntary blink rate is a clinical monitor of dopaminergic activity. Since there is disagreement in the literature on the relative neurochemical hemispheric asymmetry or laterality of dopamine, we studied the effects of differential forced unilateral nostril breathing on blink rate. This technique has been demonstrated to induce selective contralateral hemispheric stimulation as measured by relative increases in the EEG amplitude as well as alternating lateralization of plasma catecholamines. We used the artifact of the two-channel electro-oculogram to measure the endogenous eyeblink in an N = 1 design with 11 reversals of left vs. right hemisphere activation. There was a significant increase in blink rate (p less than .01) with right hemisphere activation, and this suggests that dopamine may be lateralized to the right cerebral hemisphere.