Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, 52245, USA.
Cognitive Control Collaborative, University of Iowa, Iowa City, IA, 52245, USA.
Behav Res Methods. 2024 Aug;56(5):4486-4503. doi: 10.3758/s13428-023-02197-z. Epub 2023 Aug 7.
Inhibition is a key cognitive control mechanism humans use to enable goal-directed behavior. When rapidly exerted, inhibitory control has broad, nonselective motor effects, typically demonstrated using corticospinal excitability measurements (CSE) elicited by transcranial magnetic stimulation (TMS). For example, during rapid action-stopping, CSE is suppressed at both stopped and task-unrelated muscles. While such TMS-based CSE measurements have provided crucial insights into the fronto-basal ganglia circuitry underlying inhibitory control, they have several downsides. TMS is contraindicated in many populations (e.g., epilepsy or deep-brain stimulation patients), has limited temporal resolution, produces distracting auditory and haptic stimulation, is difficult to combine with other imaging methods, and necessitates expensive, immobile equipment. Here, we attempted to measure the nonselective motor effects of inhibitory control using a method unaffected by these shortcomings. Thirty male and female human participants exerted isometric force on a high-precision handheld force transducer while performing a foot-response stop-signal task. Indeed, when foot movements were successfully stopped, force output at the task-irrelevant hand was suppressed as well. Moreover, this nonselective reduction of isometric force was highly correlated with stop-signal performance and showed frequency dynamics similar to established inhibitory signatures typically found in neural and muscle recordings. Together, these findings demonstrate that isometric force recordings can reliably capture the nonselective effects of motor inhibition, opening the door to many applications that are hard or impossible to realize with TMS.
抑制是人类用于实现目标导向行为的关键认知控制机制。当快速施加时，抑制控制具有广泛的、非选择性的运动效应，通常通过经颅磁刺激 (TMS) 引发的皮质脊髓兴奋性测量 (CSE) 来证明。例如，在快速动作停止期间，CSE 在停止和与任务无关的肌肉中均受到抑制。虽然基于 TMS 的 CSE 测量为抑制控制的额基底神经节回路提供了重要的见解，但它们也有几个缺点。TMS 在许多人群中是禁忌的（例如，癫痫或深部脑刺激患者），时间分辨率有限，产生分散注意力的听觉和触觉刺激，难以与其他成像方法结合，并且需要昂贵的、固定的设备。在这里，我们试图使用一种不受这些缺点影响的方法来测量抑制控制的非选择性运动效应。30 名男性和女性参与者在手持高精度力传感器上施加等长力，同时执行脚部反应停止信号任务。事实上，当脚部运动成功停止时，无关任务的手部的力输出也被抑制。此外，这种等长力的非选择性降低与停止信号表现高度相关，并且表现出与通常在神经和肌肉记录中发现的抑制特征相似的频率动态。总之，这些发现表明等长力记录可以可靠地捕捉运动抑制的非选择性效应，为许多难以或不可能通过 TMS 实现的应用开辟了道路。
