University of California, Berkeley.
Georgia Institute of Technology.
J Cogn Neurosci. 2022 Mar 31;34(5):877-896. doi: 10.1162/jocn_a_01837.
Task processing (e.g., the preparation and execution of responses) and task representation (e.g., the activation and maintenance of stimulus-response and context information) are two facets of cognitive control supported by lateral frontal cortex (LFC). However, the mechanistic overlap (or distinction) between these two facets is unknown. We explored this by combining a complex task mapping with a precueing procedure. Participants made match/nonmatch judgments on pairs of stimuli during fMRI recording. Precues on each trial gave variable amounts of information to the participant in anticipation of the stimulus. Our results demonstrated that regions throughout LFC were more active at the stimulus (when responses could be executed) than at the cue (when they could only be prepared), indicating that they supported execution of the task agnostic to the specific task representation. A subset of regions in the left caudal LFC showed increased activity with more cue information at the cue and the reverse at the stimulus, suggesting their involvement in reducing uncertainty within the task representation. These results suggest that one component of task processing is preparing and executing the task according to the relevant representation, confined to left caudal LFC, whereas nonrepresentational functions that occur primarily during execution are supported by different regions throughout the rest of LFC. We further conducted an exploratory investigation of connectivity between the two groups of regions in this study and their potential relationship to the frontoparietal and cingulo-opercular networks. Regions with both patterns of activity appear to be part of the frontoparietal network.
任务处理(例如,响应的准备和执行)和任务表示(例如,刺激-反应和上下文信息的激活和维持)是由外侧额叶皮层(LFC)支持的认知控制的两个方面。然而,这两个方面之间的机制重叠(或区别)尚不清楚。我们通过将复杂任务映射与预提示程序相结合来探索这一点。参与者在 fMRI 记录期间对刺激对进行匹配/不匹配判断。每次试验的预提示都会向参与者提供不同数量的信息,以预测刺激。我们的结果表明,LFC 中的许多区域在刺激时(当可以执行响应时)比在提示时(当只能准备响应时)更活跃,这表明它们支持执行与特定任务表示无关的任务。左侧 LFC 尾端的一部分区域在提示时随着提示信息的增加而显示出更高的活性,而在刺激时则相反,这表明它们参与了减少任务表示中的不确定性。这些结果表明,任务处理的一个组成部分是根据相关表示来准备和执行任务,局限于左侧 LFC 尾端,而在执行过程中主要发生的非表示功能则由 LFC 其余部分的不同区域支持。我们进一步对本研究中这两组区域之间的连通性及其与额顶叶和扣带回网络的潜在关系进行了探索性研究。具有这两种活动模式的区域似乎是额顶叶网络的一部分。