Sensorimotor synchronization (SMS) is frequently dependent on coordination of excitatory and inhibitory activity across hemispheres, as well as the cognitive control over environmental distractors. However, the timing (motor planning versus execution) and cortical regions involved in these processes remain actively debated. Functional magnetic resonance imaging data were therefore analyzed from 34 strongly right-handed healthy adults performing a cued (to initiate motor planning) SMS task with either their right or left hand (motor execution phase) based on spatially congruent or incongruent visual stimuli. Behavioral effects of incongruent stimuli were limited to the first stimulus. Functionally, greater activation was observed in left sensorimotor cortex (SMC) and right cerebellar Lobule V for congruent versus incongruent stimuli. A negative blood-oxygen level dependent response, a putative marker of neural inhibition, was present in bilateral SMC, right supplemental motor area (SMA) and bilateral cerebellar Lobule V during the motor planning, but not execution phase. The magnitude of the inhibitory response was greater in right cortical regions and cerebellar Lobule V. Homologue connectivity was associated with inhibitory activity in the right SMA, suggesting that individual differences in intrinsic connectivity may mediate transcallosal inhibition. In summary, results suggest increased inhibition (i.e., greater negative BOLD response) within the right relative to left hemisphere, which was released once motor programs were executed. Both task and intrinsic functional connectivity results highlight a critical role of the left SMA in interhemispheric inhibition and motor planning.

感觉运动同步 (SMS) 通常依赖于跨半球的兴奋性和抑制性活动的协调，以及对环境干扰因素的认知控制。然而，这些过程中涉及的时间（运动规划与执行）和皮层区域仍然存在争议。因此，我们分析了 34 名右利手的健康成年人的功能性磁共振成像数据，他们根据空间一致或不一致的视觉刺激，用右手或左手（运动执行阶段）执行提示（以启动运动规划）SMS 任务。不一致刺激的行为影响仅限于第一个刺激。在功能上，在左侧感觉运动皮层 (SMC) 和右侧小脑小叶 V 中观察到了更大的激活，用于一致与不一致的刺激。在运动计划期间，双侧 SMC、右侧补充运动区 (SMA) 和双侧小脑小叶 V 中存在负血氧水平依赖性反应，即神经抑制的假定标志物，但不是执行阶段。右侧皮质区域和小脑小叶 V 的抑制反应幅度更大。同源连接与右侧 SMA 的抑制活性相关，这表明内在连接的个体差异可能介导经胼胝体抑制。总之，结果表明右侧相对于左半球的抑制增加（即更大的负 BOLD 反应），一旦执行运动程序就会释放。