Cortical Gamma-Oscillations Modulated by Auditory-Motor Tasks-Intracranial Recording in Patients With Epilepsy

Human activities often involve hand-motor responses following external auditory verbal commands It has been believed that hand movements are predominantly driven by the contralateral primary sensorimotor cortex, whereas auditory-verbal information is processed in both superior temporal gyn. It remains unknown whether cortical activation in the superior temporal gyrus during an auditory motor task is affected by laterality of hand-motor responses Here, event-related gamma-oscillations were intracranially recorded as quantitative measures of cortical activation; we determined how cortical structures were activated by auditory-cued movement Using each hand in 15 patients with focal epilepsy. Auditory-verbal stimuli elicited augmentation of gamma-oscillations in a posterior portion of the superior temporal gyrus, whereas hand-motor responses elicited gamma-augmentation in the pre- and postcentral gyn. The magnitudes of such gamma-augmentation in the superior temporal, precentral, and postcentral gyn were significantly larger when the hand contralateral to the recorded hemisphere was required to be used for motor responses, compared with when the ipsilateral hand was. The superior temporal gyrus in each hemisphere might play a greater pivotal role when the contralateral hand needs to be used for motor responses, compared with when the ipsilateral hand does. Hum Brain Mapp 31 1627-1642, 2010. (C) 2010 Wiley-Liss, Inc.