Difference between Right and Left Activation of Sensorimotor Cortex during Finger Opposition Task -Functional MRI Study-.

In order to clarify asymmetry of functional activation in the sensorimotor cortex (SMC), we scanned 12 right-handed healthy subjects with functional MRI while they performed self-initiated sequential opposition movements of the thumb to each finger every I second with the right and left hands. Movement of the left hand resulted in greater activation of the SMC contralateral to the movements than that of the right hand (Mean BOLD signals: 11.68 with right hand, 16.82 with left hand. p<0.05). With respect to spatial distribution of activated SMC, finger movements activated contralateral SMC with the right hand, whereas bilateral SMC was activated with the left hand. These results support the hypothesis that unskillful movements, as with left hand in this study, require more neural participation than skillful movements. [ABSTRACT FROM AUTHOR]