Department of psychology, Tulane University, United States.
Program in Neuroscience, Tulane University, United States.
Neuropsychologia. 2018 Mar;111:216-228. doi: 10.1016/j.neuropsychologia.2018.01.031. Epub 2018 Feb 2.
Cognitive control of attention in conflict situations is a basic skill that is vital for goal-oriented behavior. Behavioral evidence shows that conflict control occurs over successive trials as well as longer time scales of trial blocks, but the relation among time scales as well as their neural mechanisms are unclear. This study used measures of behavior, EEG, and a simple quantitative model to test the hypothesis that conflict control at the block level is not exclusively driven by control adjustments over successive trials. Young adults performed an auditory Simon task, and the base rate of compatible vs. incompatible trials was manipulated in separate blocks (25, 50, 75% compatible). EEG data were analyzed using independent component analysis (ICA) to define cortical mechanisms of any base rate and trial-by-trial sequence effects. Reaction time measures had both sequence and base rate effects. Two fronto-medial ICA components indexed sequence and base rate effects, with specific profiles for evoked potentials and oscillations in the theta and alpha frequency bands. Predictive modeling showed that sequence effects accounted for a minority of the variance on behavioral and ICA measures (all < 36%). The results strongly suggest that the base rate manipulation affected behavior and many neural measures beyond the influence of sequence effects.
冲突情境下的注意认知控制是一种基本技能，对目标导向行为至关重要。行为证据表明，冲突控制不仅发生在连续的试次中，而且还发生在试次块的更长时间尺度上，但时间尺度之间的关系及其神经机制尚不清楚。本研究使用行为、EEG 和简单的定量模型来检验以下假设：即块水平的冲突控制不仅仅是由连续试次的控制调整驱动的。年轻成年人执行听觉 Simon 任务，在单独的块中操纵相容与不相容试次的基本比率（25%、50%、75%相容）。使用独立成分分析（ICA）对 EEG 数据进行分析，以确定任何基本比率和试次序列效应的皮质机制。反应时测量既有序列效应又有基本比率效应。两个额-内侧 ICA 成分分别标记序列和基本比率效应，在诱发电位和θ和α频带的振荡中具有特定的谱。预测模型表明，序列效应仅解释了行为和 ICA 测量值中少数的方差（均<36%）。结果强烈表明，基本比率操纵不仅影响行为，而且还影响许多神经测量值，而不仅仅是序列效应的影响。
