Raud Liisa, Huster René J
Department of Psychology, University of Oslo, Oslo, Norway.
Psychology Clinical Neurosciences Center, University of New Mexico, Albuquerque, USA.
Brain Topogr. 2017 Jul;30(4):486-501. doi: 10.1007/s10548-017-0566-y. Epub 2017 Apr 29.
Behavioral adjustments require interactions between distinct modes of cognitive control and response inhibition. Hypothetically, fast and global inhibition is exerted in the reactive control mode, whereas proactive control enables the preparation of inhibitory pathways in advance while relying on the slower selective inhibitory system. We compared the temporal progression of inhibition in the reactive and proactive control modes using simultaneous electroencephalography (EEG) and electromyography (EMG) recordings. A selective stop signal task was used where go stimuli required bimanual responses, but only one hand's response had to be suppressed in stop trials. Reactive and proactive conditions were incorporated by non-informative and informative cues, respectively. In 47% of successful stop trials, subthreshold EMG activity was detected that was interrupted as early as 150 ms after stop stimulus presentation, indicating that inhibition occurs much earlier than previously thought. Inhibition latencies were similar across the reactive and proactive control modes. The EMG of the responding hand in successful selective stop trials indicated a global suppression of ongoing motor actions in the reactive condition, and less inhibitory interference on the ongoing actions in the proactive condition. Group-level second order blind separation (SOBI) was applied to the EEG to dissociate temporally overlapping event-related potentials. The components capturing the N1 and N2 were larger in the reactive than the proactive condition. P3 activity was distributed across four components, three of which were augmented in the proactive condition. Thus, although EEG indices were modulated by the control mode, the inhibition latency remained unaffected.
行为调整需要不同认知控制模式和反应抑制之间的相互作用。假设在反应性控制模式中施加快速且全局的抑制，而前瞻性控制则在依赖较慢的选择性抑制系统的同时预先准备抑制通路。我们使用同步脑电图（EEG）和肌电图（EMG）记录比较了反应性和前瞻性控制模式下抑制的时间进程。采用了选择性停止信号任务，其中启动刺激需要双手反应，但在停止试验中仅需抑制一只手的反应。反应性和前瞻性条件分别通过非信息性和信息性线索来纳入。在47%的成功停止试验中，检测到阈下肌电活动，其在停止刺激呈现后最早150毫秒就被中断，这表明抑制比之前认为的要早得多。反应性和前瞻性控制模式下的抑制潜伏期相似。成功的选择性停止试验中反应手的肌电图表明，在反应性条件下对正在进行的运动动作有全局抑制，而在前瞻性条件下对正在进行的动作的抑制干扰较小。将组水平二阶盲分离（SOBI）应用于脑电图，以分离时间上重叠的事件相关电位。捕捉N1和N2的成分在反应性条件下比前瞻性条件下更大。P3活动分布在四个成分中，其中三个在前瞻性条件下增强。因此，尽管脑电图指标受控制模式调节，但抑制潜伏期不受影响。
