Selective hemispheric stimulation by unilateral forced nostril breathing.

We have previously demonstrated by the integration of EEG amplitudes, that an ultradian rhythm of alternating cerebral dominance exists in humans. This rhythm is tightly coupled with the nasal cycle, since its lateralization correlates with shifts in airflow through the left and right nostrils, where relatively greater integrated amplitudes in one hemisphere correspond to predominant airflow in the contralateral nostril. The nasal cycle is known to be regulated by the sympathetic and parasympathetic branches of the autonomic nervous system. This dynamic lateralization of alternating activity in the autonomic nervous system exists in other peripheral structures and is also likely to be the mode of regulation of the cortical rhythm. This paper shows that forced nostril breathing in one nostril produces a relative increase in the EEG amplitude in the contralateral hemisphere. This phenomena was demonstrated in 5 out of 5 untrained subjects. These results suggest the possibility of a non-invasive approach in the treatment of states of psychopathology where lateralized cerebral dysfunction have been shown to occur.