Movement Neuroscience Laboratory, Department of Exercise Sciences, University of Auckland, Auckland 1142, New Zealand.
Centre for Brain Research, University of Auckland, Auckland 1142, New Zealand.
J Neurosci. 2023 Feb 8;43(6):1008-1017. doi: 10.1523/JNEUROSCI.1712-22.2022. Epub 2023 Jan 6.
Response inhibition is essential for terminating inappropriate actions. A substantial response delay may occur in the nonstopped effector when only part of a multieffector action is terminated. This stopping-interference effect has been attributed to nonselective response inhibition processes and can be reduced with proactive cuing. This study aimed to elucidate the role of interhemispheric primary motor cortex (M1-M1) influences during selective stopping with proactive cuing. We hypothesized that stopping-interference would be reduced as stopping certainty increased because of proactive recruitment of interhemispheric facilitation or inhibition when cued to respond or stop, respectively. Twenty-three healthy human participants of either sex performed a bimanual anticipatory response inhibition paradigm with cues signaling the likelihood of a stop-signal occurring. Dual-coil transcranial magnetic stimulation was used to determine corticomotor excitability (CME), interhemispheric inhibition (IHI), and interhemispheric facilitation (IHF) in the left hand at rest and during response preparation. Response times slowed and stopping-interference decreased with increased stopping certainty. Proactive response inhibition was marked by a reduced rate of rise and faster cancel time in electromyographical bursts during stopping. There was a nonselective release of IHI but not CME from rest to in-task response preparation, whereas IHF was not observed in either context. An effector-specific reduction in CME but no reinstatement of IHI was observed when the left hand was cued to stop. These findings indicate that stopping speed and selectivity are better with proactive cueing and that interhemispheric M1-M1 channels modulate inhibitory tone during response preparation to support going but not proactive response inhibition. Response inhibition is essential for terminating inappropriate actions and, in some cases, may be required for only part of a multieffector action. The present study examined interhemispheric influences between the primary motor cortices during selective stopping with proactive cuing. Stopping selectivity was greater with increased stopping certainty and was marked by proactive adjustments to the hand cued to stop and hand cued to respond separately. Inhibitory interhemispheric influences were released during response preparation but were not directly involved in proactive response inhibition. These findings indicate that between-hand stopping can be selective with proactive cuing, but cue-related improvements are unlikely to reflect the advance engagement of interhemispheric influences between primary motor cortices.
反应抑制对于终止不当行为至关重要。当多动作的一部分被终止时，非停止效应器中可能会出现大量的反应延迟。这种停止干扰效应归因于非选择性的反应抑制过程，并且可以通过主动提示来减少。本研究旨在阐明在主动提示选择性停止时，大脑两半球初级运动皮层（M1-M1）之间影响的作用。我们假设，由于在提示响应或停止时主动募集大脑两半球促进或抑制，因此随着停止确定性的增加，停止干扰会减少。 23 名健康的男性和女性参与者进行了一项双手预期反应抑制范式，提示信号发生停止信号的可能性。使用双线圈经颅磁刺激来确定左手在休息和响应准备期间的运动皮质兴奋性（CME），大脑两半球抑制（IHI）和大脑两半球促进（IHF）。随着停止确定性的增加，反应时间变慢，停止干扰减少。在停止过程中，主动抑制的标志是肌电图爆发的上升率降低和取消时间更快。从休息到任务响应准备过程中，存在非选择性的 IHI 释放，但 CME 没有释放，而在两种情况下均未观察到 IHF。当左手被提示停止时，观察到 CME 的效应器特异性降低，但 IHI 没有恢复。这些发现表明，主动提示时停止速度和选择性更好，并且大脑两半球 M1-M1 通道在响应准备期间调节抑制性音调，以支持前进但不能支持主动响应抑制。反应抑制对于终止不当行为至关重要，在某些情况下，可能只需要多动作的一部分。本研究在主动提示下选择性停止期间检查了大脑两半球初级运动皮层之间的相互影响。随着停止确定性的增加，停止选择性更大，并且通过分别针对停止和响应提示的手进行主动调整来标记。在响应准备期间释放抑制性大脑两半球影响，但它们不直接参与主动响应抑制。这些发现表明，主动提示时双手之间的停止可以是选择性的，但是提示相关的改善不太可能反映大脑两半球初级运动皮层之间的相互影响的提前参与。
