Right lateralized motor cortex activation during volitional blinking

Using (H2O)-O-15 positron emission tomography in 6 healthy volunteers, we f ound that self-initiated and externally cued blinking activated the right p rimary motor cortex and supplementary motor area (SMA). The left dorsolater al prefrontal cortex (DLPFC) and the rostral SMA showed greater activation during the self-initiated task compared to the externally cued task. This s tudy confirms the hypothesis of right hemispheric lateralization of volitio nal blinking derived from observations in stroke patients. Furthermore, it underscores the role of DLPFC and rostral SMA in self-initiated movements, which has been found in similar experiments with hand movements.