Shenzhen Key Laboratory of Affective and Social Cognitive Science, School of Psychology, Shenzhen University, Shenzhen, China.
Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing, China; School of Psychology, Shaanxi Normal University, Xi'an, China.
Neuroimage. 2020 Oct 15;220:117158. doi: 10.1016/j.neuroimage.2020.117158. Epub 2020 Jul 11.
Evidence indicates the significance of the fronto-parietal regions and inertia sensory processing from previous trials in cognitive flexibility. However, how flexible cognitive performance is achieved by causal interactions between cortical regions, particularly those between the fronto-parietal and stimulus processing regions, remains unknown. In the current study, the effective connectivity between the fronto-parietal and visual regions was examined in the context of a cued task-switching paradigm. We found that the fronto-parietal and visual cortex were differently activated during task transition (task repeat and task switch). Importantly, dynamic causal modeling (DCM) analysis revealed that task transition could modulate the effective connectivity between the fronto-parietal and visual cortex: task repeat decreased, while task switch enhanced, the coupling between the posterior parietal cortex (PPC) and the visual cortex. Furthermore, Granger causality analysis (GCA) showed that the dominant direction of influence was from the fronto-parietal regions to the visual cortex. Finally, individual differences in the top-down influence from the PPC to the visual cortex and the corresponding neural adjustment (task switch‒task repeat) was negatively associated with the behavioral switch cost. Our findings suggest that the interaction between the fronto-parietal and stimulus processing regions, particularly the top-down influence from the PPC to the visual cortex, is of particular importance in flexible cognitive performance.
证据表明，额顶区域和来自先前试验的惯性感觉处理在认知灵活性中具有重要意义。然而，皮质区域之间，特别是额顶区域和刺激处理区域之间的因果相互作用如何导致灵活的认知表现，目前尚不清楚。在本研究中，在提示任务转换范式的背景下，研究了额顶和视觉区域之间的有效连接。我们发现，在任务转换（任务重复和任务切换）期间，额顶和视觉皮层的激活不同。重要的是，动态因果建模（DCM）分析表明，任务转换可以调节额顶和视觉皮层之间的有效连接：任务重复降低，而任务切换增强了后顶叶皮层（PPC）和视觉皮层之间的耦合。此外，格兰杰因果分析（GCA）表明，影响的主导方向是从前额顶区域到视觉皮层。最后，个体之间从 PPC 到视觉皮层的自上而下影响的差异以及相应的神经调整（任务切换-任务重复）与行为切换成本呈负相关。我们的研究结果表明，额顶和刺激处理区域之间的相互作用，特别是从 PPC 到视觉皮层的自上而下的影响，在灵活的认知表现中具有特别重要的意义。
