Ariani Giacomo, Shahbazi Mahdiyar, Diedrichsen Jörn
Western Institute for Neuroscience, Western University, London, Ontario N6A3K7, Canada.
Departments of Computer Science, Western University, London, Ontario N6A3K7, Canada.
J Neurosci. 2025 Jan 15;45(3):e1300242024. doi: 10.1523/JNEUROSCI.1300-24.2024.
Production of rapid movement sequences relies on preparation before (preplanning) and during (online planning) movement. Here, we compared these processes and asked whether they recruit different cortical areas. Human participants performed three single-finger and three multifinger sequences in a delayed-movement paradigm while undergoing a 7 T functional MRI. During preparation, primary motor (M1) and somatosensory (S1) areas showed preactivation of the first movement, even without increases in overall activation. During production, the temporal summation of activity patterns corresponding to constituent fingers explained activity in these areas (M1 and S1). In contrast, the dorsal premotor cortex (PMd) and anterior superior parietal lobule (aSPL) showed substantial activation during the preparation (preplanning) of multifinger compared with single-finger sequences. These regions (PMd and aSPL) were also more active during production of multifinger sequences, suggesting that pre- and online planning may recruit the same regions. However, we observed small but robust differences between the two contrasts, suggesting distinct contributions to pre- and online planning. Multivariate analysis revealed sequence-specific representations in both PMd and aSPL, which remained stable across both preparation and production phases. Our analyses show that these areas maintain a sequence-specific representation before and during sequence production, likely guiding the execution-related areas in the production of rapid movement sequences.
快速运动序列的产生依赖于运动前（预先规划）和运动过程中（在线规划）的准备。在此，我们比较了这些过程，并询问它们是否募集不同的皮质区域。人类参与者在延迟运动范式中执行三个单指和三个多指序列，同时接受7T功能磁共振成像。在准备过程中，即使总体激活没有增加，初级运动（M1）和躯体感觉（S1）区域也显示出第一个动作的预激活。在动作产生过程中，与组成手指相对应的活动模式的时间总和解释了这些区域（M1和S1）的活动。相比之下，与单指序列相比，在多指序列的准备（预先规划）过程中，背侧运动前皮层（PMd）和顶上叶前部小叶（aSPL）显示出大量激活。在多指序列产生过程中，这些区域（PMd和aSPL）也更活跃，这表明预先规划和在线规划可能募集相同的区域。然而，我们在两种对比之间观察到了微小但显著的差异，表明对预先规划和在线规划有不同的贡献。多变量分析揭示了PMd和aSPL中特定于序列的表征，这些表征在准备和产生阶段都保持稳定。我们的分析表明，这些区域在序列产生之前和过程中维持特定于序列的表征，可能在快速运动序列的产生中指导与执行相关的区域。
