Department of Psychology, University of York, York, United Kingdom.
McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
Elife. 2022 Mar 21;11:e74011. doi: 10.7554/eLife.74011.
While reading, our mind can wander to unrelated autobiographical information, creating a perceptually decoupled state detrimental to narrative comprehension. To understand how this mind-wandering state emerges, we asked whether retrieving autobiographical content necessitates functional disengagement from visual input. In Experiment 1, brain activity was recorded using functional magnetic resonance imaging (fMRI) in an experimental situation mimicking naturally occurring mind-wandering, allowing us to precisely delineate neural regions involved in memory and reading. Individuals read expository texts and ignored personally relevant autobiographical memories, as well as the opposite situation. Medial regions of the default mode network (DMN) were recruited during memory retrieval. In contrast, left temporal and lateral prefrontal regions of the DMN, as well as ventral visual cortex, were recruited when reading for comprehension. Experiment two used functional connectivity both at rest and during tasks to establish that (i) DMN regions linked to memory are more functionally decoupled from regions of ventral visual cortex than regions in the same network engaged when reading; and (ii) individuals with more self-generated mental contents and poorer comprehension, while reading in the lab, showed more decoupling between visually connected DMN sites important for reading and primary visual cortex. A similar pattern of connectivity was found in Experiment 1, with greater coupling between this DMN site and visual cortex when participants reported greater focus on reading in the face of conflict from autobiographical memory cues; moreover, the retrieval of personally relevant memories increased the decoupling of these sites. These converging data suggest we lose track of the narrative when our minds wander because generating autobiographical mental content relies on cortical regions within the DMN which are functionally decoupled from ventral visual regions engaged during reading.
在阅读时，我们的思维可能会游离到与自传信息无关的内容上，从而产生不利于叙事理解的感知分离状态。为了理解这种思维漫游状态是如何产生的，我们研究了检索自传内容是否需要与视觉输入进行功能脱离。在实验 1 中，我们使用功能磁共振成像（fMRI）在模拟自然思维漫游的实验情境中记录大脑活动，从而能够精确描绘参与记忆和阅读的神经区域。参与者阅读说明文并忽略与个人相关的自传记忆，以及相反的情况。默认模式网络（DMN）的内侧区域在记忆检索过程中被招募。相比之下，当阅读以理解时，DMN 的左侧颞叶和外侧前额叶区域以及腹侧视觉皮层被招募。实验二使用静息态和任务态的功能连接来建立以下观点：（i）与记忆相关的 DMN 区域与腹侧视觉皮层的功能分离程度大于阅读时同一网络中参与的区域；（ii）在实验室阅读时，自我生成的心理内容更多且理解能力较差的个体，在阅读时重要的视觉连接 DMN 部位与初级视觉皮层之间表现出更大的分离。在实验 1 中也发现了类似的连接模式，当参与者在自传记忆线索的冲突下报告更专注于阅读时，该 DMN 部位与视觉皮层之间的耦合更强；此外，个人相关记忆的检索增加了这些部位的分离。这些收敛的数据表明，当我们的思维漫游时，我们会失去对叙事的关注，因为生成自传心理内容依赖于默认模式网络内的皮质区域，这些区域与阅读时参与的腹侧视觉区域功能分离。
