Feldman Rebecca, Quale Maya, Etzel Joset, Braver Todd S
Department of Psychological and Brain Sciences, Washington University in St. Louis.
bioRxiv. 2025 May 12:2025.05.09.653198. doi: 10.1101/2025.05.09.653198.
Recent prior work suggests a preferential relationship between working memory capacity (WMC) and proactive control, yet the neural mechanisms that support this relationship are still not well understood. We directly addressed this question by leveraging the Dual Mechanisms of Cognitive Control (DMCC) project, as it employed a fMRI neuroimaging design optimized to test for individual differences (sample N > 100), with task variants that independently assessed proactive and reactive control relative to baseline conditions. Behavioral analyses replicated prior work with the AX-CPT paradigm, in which a measure of target preparation based on contextual cues (the A-cue Bias index) was both reliably increased under task conditions encouraging proactive control and positively associated with WMC. Analyses of fMRI activity indicated that A-cue Bias was selectively linked to increased cue-related neural activity in left motor cortex (lMOT). Additionally, WMC was associated with increased cue-related activation in right dorsolateral prefrontal cortex (rDLPFC), even when statistically controlling for baseline and reactive conditions. The relationship between these two effects was supported by a latent path analysis, which suggested that the rDLPFC-lMOT circuit preferentially mediates the WMC-A-cue Bias relationship present under proactive task conditions. The results suggest this neural circuit may translate strategic task goals into active response preparation as a mechanism of proactive control. Individuals high in WMC may be better able to implement proactive task strategies when instructed via contextual cues. The sensitivity of the rDLPFC-lMOT circuit to individual differences suggest it as a potential target for cognitive enhancement.
近期的前期研究表明，工作记忆容量（WMC）与主动控制之间存在一种优先关系，然而，支持这种关系的神经机制仍未得到充分理解。我们通过利用认知控制双重机制（DMCC）项目直接解决了这个问题，因为该项目采用了功能磁共振成像（fMRI）神经成像设计，该设计经过优化以测试个体差异（样本量N>100），其任务变体相对于基线条件独立评估主动控制和反应控制。行为分析重复了之前使用AX连续性能测试（AX-CPT）范式的研究，在该范式中，基于情境线索的目标准备度量（A线索偏差指数）在鼓励主动控制的任务条件下可靠地增加，并且与WMC呈正相关。fMRI活动分析表明，A线索偏差与左侧运动皮层（lMOT）中与线索相关的神经活动增加有选择性地联系。此外，即使在对基线和反应条件进行统计控制时，WMC也与右侧背外侧前额叶皮层（rDLPFC）中与线索相关的激活增加有关。潜在路径分析支持了这两种效应之间的关系，该分析表明rDLPFC-lMOT回路优先介导了主动任务条件下存在的WMC-A线索偏差关系。结果表明，这种神经回路可能将战略任务目标转化为积极的反应准备，作为主动控制的一种机制。当通过情境线索进行指导时，WMC高的个体可能更有能力实施主动任务策略。rDLPFC-lMOT回路对个体差异的敏感性表明它是认知增强的潜在目标。
