Centre for Studies and Research in Cognitive Neuroscience, Cesena, Italy.
Centre for Studies and Research in Cognitive Neuroscience, Cesena, Italy; Department of Psychology 'Renzo Canestrari', University of Bologna, Bologna, Italy.
Neuropsychologia. 2023 Sep 9;188:108639. doi: 10.1016/j.neuropsychologia.2023.108639. Epub 2023 Jul 7.
Distraction reflects a drift of attention away from the task at hand towards task-irrelevant external or internal information (mind-wandering). The right posterior parietal cortex (PPC) and the medial prefrontal cortex (mPFC) are known to mediate attention to external information and mind-wandering, respectively, but it is not clear whether they support each process selectively or rather they play similar roles in supporting both. In this study, participants performed a visual search task including salient color singleton distractors before and after receiving cathodal (inhibitory) transcranial direct current stimulation (tDCS) to the right PPC, the mPFC, or sham tDCS. Thought probes assessed the intensity and contents of mind-wandering during visual search. The results show that tDCS to the right PPC but not mPFC reduced the attentional capture by the singleton distractor during visual search. tDCS to both mPFC and PPC reduced mind-wandering, but only tDCS to the mPFC specifically reduced future-oriented mind-wandering. These results suggest that the right PPC and mPFC play a different role in directing attention towards task-irrelevant information. The PPC is involved in both external and internal distraction, possibly by mediating the disengagement of attention from the current task and its reorienting to salient information, be this a percept or a mental content (mind-wandering). By contrast, the mPFC uniquely supports mind-wandering, possibly by mediating the endogenous generation of future-oriented thoughts capable to draw attention inward, away from ongoing activities.
分心反映了注意力从手头的任务漂移到与任务无关的外部或内部信息（思维漫游）。已知右顶叶后皮质（PPC）和内侧前额叶皮质（mPFC）分别介导对外界信息和思维漫游的注意力，但尚不清楚它们是选择性地支持这两个过程，还是它们在支持这两个过程中发挥类似的作用。在这项研究中，参与者在接受右 PPC、mPFC 或假 tDCS 经颅直流电刺激（tDCS）之前和之后执行了一项包括突出颜色单一分散注意力的视觉搜索任务。思维探测评估了视觉搜索过程中思维漫游的强度和内容。结果表明，右 PPC 的 tDCS 而不是 mPFC 减少了视觉搜索中单一分散注意力的注意捕获。mPFC 和 PPC 的 tDCS 都减少了思维漫游，但只有 mPFC 的 tDCS 特异性地减少了面向未来的思维漫游。这些结果表明，右 PPC 和 mPFC 在引导注意力朝向与任务无关的信息方面发挥着不同的作用。PPC 参与了外部和内部分心，可能通过介导注意力从当前任务的脱离和重新定向到突出的信息，无论是感知还是心理内容（思维漫游）。相比之下，mPFC 独特地支持思维漫游，可能通过介导能够将注意力从正在进行的活动中吸引到内部的未来导向思维的内源性产生来实现。
