Korolczuk Inga, Burle Boris, Coull Jennifer T, Śmigasiewicz Kamila
Laboratoire des Neurosciences Cognitives, Aix-Marseille University & CNRS, Marseille, France.
Institute of Applied Psychology, Jagiellonian University, Krakow, Poland.
J Cogn Neurosci. 2022 Jan 5;34(2):273-289. doi: 10.1162/jocn_a_01795.
The brain can anticipate the time of imminent events to optimize sensorimotor processing. Yet, there can be behavioral costs of temporal predictability under situations of response conflict. Here, we sought to identify the neural basis of these costs and benefits by examining motor control processes in a combined EEG-EMG study. We recorded electrophysiological markers of response activation and inhibition over motor cortex when the onset-time of visual targets could be predicted, or not, and when responses necessitated conflict resolution, or not. If stimuli were temporally predictable but evoked conflicting responses, we observed increased intertrial consistency in the delta range over the motor cortex involved in response implementation, perhaps reflecting increased response difficulty. More importantly, temporal predictability differentially modulated motor cortex activity as a function of response conflict before the response was even initiated. This effect occurred in the hemisphere ipsilateral to the response, which is involved in inhibiting unwanted actions. If target features all triggered the same response, temporal predictability increased cortical inhibition of the incorrect response hand. Conversely, if different target features triggered two conflicting responses, temporal predictability decreased inhibition of the incorrect, yet prepotent, response. This dissociation reconciles the well-established behavioral benefits of temporal predictability for nonconflicting responses as well as its costs for conflicting ones by providing an elegant mechanism that operates selectively over the motor cortex involved in suppressing inappropriate actions just before response initiation. Taken together, our results demonstrate that temporal information differentially guides motor activity depending on response choice complexity.
大脑能够预测即将发生的事件的时间，以优化感觉运动处理。然而，在反应冲突的情况下，时间可预测性可能会带来行为成本。在此，我们试图通过在一项脑电图-肌电图联合研究中检查运动控制过程，来确定这些成本和收益的神经基础。当视觉目标的起始时间可以预测或不可预测时，以及当反应需要解决冲突或不需要解决冲突时，我们记录了运动皮层上反应激活和抑制的电生理标记。如果刺激在时间上是可预测的，但引发了冲突反应，我们观察到参与反应执行的运动皮层上δ频段的试次间一致性增加，这可能反映了反应难度的增加。更重要的是，在反应甚至尚未启动之前，时间可预测性就根据反应冲突对运动皮层活动进行了不同的调节。这种效应发生在与反应同侧的半球，该半球参与抑制不必要的动作。如果目标特征都触发相同的反应，时间可预测性会增加对错误反应手的皮层抑制。相反，如果不同的目标特征触发两种冲突反应，时间可预测性会降低对错误但占优势反应的抑制。这种分离通过提供一种在反应启动前选择性地作用于参与抑制不适当动作的运动皮层的精妙机制，调和了时间可预测性对非冲突反应已确立的行为益处及其对冲突反应的成本。综上所述，我们的结果表明，时间信息根据反应选择的复杂性对运动活动进行不同的引导。
