Long Zhengkun, Northoff Georg, Fu Xiaolan
State Key Laboratory of Cognitive Science and Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China.
Proc Natl Acad Sci U S A. 2025 Jun 3;122(22):e2416387122. doi: 10.1073/pnas.2416387122. Epub 2025 May 30.
Mind wandering attenuates widespread sensory and motor processing, both of which are mediated by phase coherence. However, it remains unclear i) whether mind wandering impacts both sensory input and motor output processing by modulating ii) neural entrainment to external stimuli, as measured by intertrial phase coherence (ITPC), and specifically iii) whether task difficulty with different degrees of attentional demands moderates the impact of mind wandering on phase coherence. Using the thought-probe method, we assessed participants' attentional states during different sensory and motor tasks with varying task difficulty. We found that mind wandering decreased ITPC exclusively in less demanding tasks but not in difficult ones, regardless of whether the tasks involved visual input or motor output processing. Our results suggest that external task difficulty may modulate the balance between external and internal cognitive processing (e.g., mind wandering), with simpler tasks facilitating internally oriented cognition and increasing mind wandering. This balance between internal mind wandering and external task difficulty is mediated, in part, by phase coherence, which serves as an underlying neural mechanism. Collectively, our findings support the hypothesis that phase coherence and its dynamics (ITPC) play a key role in mediating the reciprocal balance of internal and external cognition-this suggests their partly shared cognitive-executive resources as entailed by the recently proposed Baseline model of cognition.
思绪游走会减弱广泛的感觉和运动处理，这两者均由相位相干性介导。然而，目前尚不清楚：其一，思绪游走是否通过调节其二，如通过试次间相位相干性（ITPC）所测量的，对外部刺激的神经同步化，来影响感觉输入和运动输出处理；具体而言其三，具有不同程度注意力需求的任务难度是否会调节思绪游走对相位相干性的影响。我们使用思维探测法，在不同难度的感觉和运动任务中评估参与者的注意力状态。我们发现，无论任务涉及视觉输入还是运动输出处理，思绪游走仅在要求较低的任务中降低ITPC，而在困难任务中则不会。我们的结果表明，外部任务难度可能会调节外部和内部认知处理（如思绪游走）之间的平衡，较简单的任务会促进内部导向的认知并增加思绪游走。内部思绪游走和外部任务难度之间的这种平衡部分由相位相干性介导，相位相干性是一种潜在的神经机制。总体而言，我们的研究结果支持这样一种假设，即相位相干性及其动态变化（ITPC）在介导内部和外部认知的相互平衡中起关键作用——这表明它们部分共享了最近提出的认知基线模型所涉及的认知执行资源。
