Cerebral Potentials Preceding Right and Left Unilateral and Bilateral Finger Movements in Sinistrals

Abstract

Publisher Summary This chapter discusses cerebral potentials preceding right and left unilateral and bilateral finger movements in sinistrals. Right-handed subjects are investigated with respect to the cerebral potentials preceding bilateral and right unilateral finger movements. Bereitschaftpotentials (BP) in the bilateral condition are larger over the right (non-dominant) hemisphere. To account for these somewhat unexpected findings, it is postulated that the cerebral activity necessary to generate the movement of the non-dominant finger is perhaps greater than that required of the more practiced dominant hemisphere. In the present investigation, similar experiments are carried out in left-handed subjects, recording cerebral potentials prior to left unilateral, right unilateral and bilateral finger movement. The motor potential is defined as the additional negativity over motor cortex contralateral to a unilateral movement. It occurs within the last 100msec (mean 60 msec) prior to the first muscle action potential. It must be extracted from the bilateral BP by using bipolar derivations.