Ipsilateral and contralateral motor inhibitory control in musical and vocalization tasks.

The inhibitory motor control mechanisms in human singing and vocalization are not well understood. Using transcranial magnetic stimulation (TMS), we show that singing resulted in right-sided prolongation of ipsilateral silent period and bilateral reduction in contralateral silent period. Reading led to reduced contralateral silent period duration with right-sided TMS only, but no significant inhibitory changes, both ipsilateral and contralateral, were evident with humming. The findings support the presence of enhanced interhemispheric inhibitory motor interaction during singing, as opposed to reading tasks, in dynamic word generation coupled with production of melody.