Center for Brain Disorders and Cognitive Sciences, School of Psychology, Shenzhen University, Shenzhen 518060, China.
Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518060, China.
Cereb Cortex. 2023 Jul 5;33(14):8967-8979. doi: 10.1093/cercor/bhad175.
Cognitive control involves evidence accumulation and response thresholding, but the neural underpinnings of these 2 processes are poorly understood. Based on recent findings that midfrontal theta phase coordinates the correlation between theta power and reaction time during cognitive control, this study investigated whether and how theta phase would modulate the relationships between theta power and evidence accumulation and response thresholding in human participants when they performed a flanker task. Our results confirmed the modulation of theta phase on the correlations between ongoing midfrontal theta power and reaction time under both conditions. Using hierarchical drift-diffusion regression modeling, we found that in both conditions, theta power was positively associated with boundary separation in phase bins with optimal power-reaction time correlations, whereas the power-boundary correlation decreased to nonsignificance in phase bins with reduced power-reaction time correlations. In contrast, the power-drift rate correlation was not modulated by theta phase, but by cognitive conflict. Drift rate was positively correlated with theta power for the bottom-up processing in the non-conflict condition, whereas it was negatively correlated with theta power for the top-down control to address conflict. These findings suggest that evidence accumulation is likely to be a phase-coordinated continuous process, whereas thresholding may be a phase-specific transient process.
认知控制涉及证据积累和反应阈值，但这两个过程的神经基础理解甚少。基于最近的发现，即前额θ相位协调认知控制期间θ功率和反应时间之间的相关性，本研究调查了当人类参与者执行侧抑制任务时，θ相位是否以及如何调节θ功率与证据积累和反应阈值之间的关系。我们的结果证实了θ相位对两种情况下前额θ功率与反应时间之间相关性的调制作用。使用层次漂移扩散回归建模，我们发现，在两种情况下，θ功率与相位区间中最佳功率-反应时间相关性的边界分离呈正相关，而在功率-反应时间相关性降低的相位区间中，功率-边界相关性降低到无显著水平。相比之下，θ相位不会调制功率-漂移率相关性，而是由认知冲突调制。在非冲突条件下，自下而上的处理中，漂移率与θ功率呈正相关，而在解决冲突时，漂移率与θ功率呈负相关。这些发现表明，证据积累可能是一个相位协调的连续过程，而阈值可能是一个相位特定的瞬态过程。
