Functional specificity of human premotor-motor cortical interactions during action selection
Functional specificity of human premotor-motor cortical interactions during action selection
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DOI：
10.1111/j.1460-9568.2007.05795.x
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发表时间：
2007-10-01
影响因子：
3.4
通讯作者：
Rushworth, Matthew F. S.
中科院分区：
文献类型：
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作者：
O'Shea, Jacinta;Sebastian, Catherine;Rushworth, Matthew F. S.
双脉冲经颅磁刺激(TMS)揭示了背侧运动前皮质(PMD)和初级运动皮质(M1)之间的功能联系。我们测试了这种连接是否会在已知依赖于这些回路的认知过程(反应选择)中受到调节。PMD-M1TMS在提示后75ms选择手动反应易化运动诱发电位(MEP)。MEP在50ms的反应执行控制任务中被促进，这表明75ms的PMD-M1相互作用在功能上是特定于反应选择过程的。100ms时，PMD-M1TMS延迟选择反应时间(RT)。重要的是，MEP(75ms)和RT(100ms)效应以一种特定于手的方式相互关联。当用M1对侧手作出反应时，MEP与较慢的RTS相关。当用同侧的M1手作反应时，MEP与较快的RTS相关。仅限于M1的成对脉冲TM没有产生这些效应，证实了PMD输入的因果影响。这项研究表明，反应选择信号在反应早期(75-100ms)在PMD中演化，影响M1并影响行为。这种相互作用在时间上、解剖学上和功能上都是特定的，并在选择进行哪种运动时具有因果作用。
Functional connections between dorsal premotor cortex (PMd) and primary motor cortex (M1) have been revealed by paired-pulse transcranial magnetic stimulation (TMS). We tested if such connections would be modulated during a cognitive process (response selection) known to rely on those circuits. PMd-M1 TMS applied 75 ms after a cue to select a manual response facilitated motor-evoked potentials (MEPs). MEPs were facilitated at 50 ms in a control task of response execution, suggesting that PMd-M1 interactions at 75 ms are functionally specific to the process of response selection. At 100 ms, PMd-M1 TMS delayed choice reaction time (RT). Importantly, the MEP (at 75 ms) and the RT (at 100 ms) effects were correlated in a way that was hand-specific. When the response was made with the M1-contralateral hand, MEPs correlated with slower RTs. When the response was made with the M1-ipsilateral hand, MEPs correlated with faster RTs. Paired-pulse TMS confined to M1 did not produce these effects, confirming the causal influence of PMd inputs. This study shows that a response selection signal evolves in PMd early during the reaction period (75-100 ms), impacts on M1 and affects behaviour. Such interactions are temporally, anatomically and functionally specific, and have a causal role in choosing which movement to make.