Su Wen, Guo Qiang, Li You, Zhang Kun, Zhang Yanni, Chen Qi
Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, China; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China.
Epilepsy Center, Guangdong Sanjiu Brain Hospital, Guangzhou, China.
Cortex. 2020 Oct;131:195-209. doi: 10.1016/j.cortex.2020.07.014. Epub 2020 Aug 12.
Momentary lapses in attention disrupt goal-directed behaviors, and have been associated with increased pre-stimulus activity in the default mode network (DMN). The human brain often encounters multisensory inputs. It remains unknown, however, whether the neural mechanisms underlying attentional lapses are supra-modal or modality-dependent. To answer this question in the present functional magnetic resonance imaging (fMRI) study, we asked participants to respond to either visual or auditory targets in a multisensory paradigm, and focused on the pre-stimulus neural signals underlying attentional lapses, which resulted in impaired task performance, in terms of both delayed RTs and behavioral errors, in different sensory modalities. Behaviorally, mean reaction times (RTs) were equivalent between the visual and auditory modality. At the neural level, increased pre-stimulus neural activity in the majority of the core DMN regions, including medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and left angular gyrus (AG), predicted delayed RTs more effectively in the visual than auditory modality. Especially, increased pre-stimulus activity in the mPFC predicted not only delayed RTs but also errors, more effectively in the visual than auditory modality. On the other hand, increased pre-stimulus activity in the anterior precuneus predicted both prolonged RTs and errors more effectively in the auditory than visual modality. Moreover, a supra-modal mechanism was revealed in the left middle temporal gyrus (MTG), which belongs to the posterior DMN. Increased pre-stimulus neural activity in the left MTG predicted impaired task performance in both the visual and auditory modality. Taken together, the core DMN regions manifest vision-dependent mechanisms of attentional lapses while a novel region in the anterior precuneus shows audition-dependent mechanisms of attentional lapses. Moreover, left MTG in the posterior DMN manifests a supra-modal mechanism of attentional lapses, independent of the modality of sensory inputs.
注意力的瞬间 lapse 会干扰目标导向行为，并与默认模式网络（DMN）中刺激前活动的增加有关。人类大脑经常会遇到多感官输入。然而，注意力 lapse 背后的神经机制是超模态的还是依赖于模态的，目前尚不清楚。在本功能磁共振成像（fMRI）研究中，为了回答这个问题，我们要求参与者在多感官范式中对视觉或听觉目标做出反应，并关注注意力 lapse 背后的刺激前神经信号，这导致了不同感官模态下任务表现受损，表现为反应时间延迟和行为错误。在行为层面，视觉和听觉模态之间的平均反应时间（RTs）相当。在神经层面，包括内侧前额叶皮质（mPFC）、后扣带回皮质（PCC）和左角回（AG）在内的大多数核心 DMN 区域中，刺激前神经活动的增加在视觉模态中比在听觉模态中更有效地预测了反应时间延迟。特别是，mPFC 中刺激前活动的增加不仅预测了反应时间延迟，还预测了错误，在视觉模态中比在听觉模态中更有效。另一方面，前楔叶中刺激前活动的增加在听觉模态中比在视觉模态中更有效地预测了反应时间延长和错误。此外，在属于后 DMN 的左颞中回（MTG）中揭示了一种超模态机制。左 MTG 中刺激前神经活动的增加预测了视觉和听觉模态下的任务表现受损。综上所述，核心 DMN 区域表现出注意力 lapse 的视觉依赖机制，而前楔叶中的一个新区域显示出注意力 lapse 的听觉依赖机制。此外，后 DMN 中的左 MTG 表现出注意力 lapse 的超模态机制，独立于感觉输入的模态。
