Viviani P, Perani D, Grassi F, Bettinardi V, Fazio F
Department of Psychobiology, FAPSE, University of Geneva, Switzerland.
Exp Brain Res. 1998 Jun;120(4):531-6. doi: 10.1007/s002210050428.
It is known that, when both forearms are rotated rhythmically and symmetrically, the dominant hand leads in time by about 25 ms, irrespective of movement speed. Positron emission tomography was used to test the hypothesis that the asynchrony results from a functional hemispheric asymmetry. We found that in normal, adult right-handers portions of the motor and premotor motor areas are more active in the left than in the right hemisphere. The converse pattern was observed in left-handers. The results suggest that at least some components of the neural processing involved in bimanual coordination are carried out only in the hemisphere contralateral to the dominant hand. In particular, between-hands asynchrony may reflect the time for dispatching pace-setting commands to the contralateral hemisphere.
众所周知，当双臂有节奏且对称地转动时，无论运动速度如何，优势手在时间上领先约25毫秒。正电子发射断层扫描被用于检验如下假设：这种不同步是由功能性半球不对称导致的。我们发现，在正常的成年右利手个体中，运动和运动前区的部分区域在左半球比右半球更活跃。在左利手个体中观察到相反的模式。结果表明，双上肢协调中涉及的神经处理的至少一些成分仅在与优势手对侧的半球中进行。特别是，双手之间的不同步可能反映了向对侧半球发送起搏指令的时间。
