Department of Psychology, University of York, York YO10 5DD, United Kingdom
Department of Psychology, University of York, York YO10 5DD, United Kingdom.
J Neurosci. 2021 Apr 21;41(16):3679-3691. doi: 10.1523/JNEUROSCI.1782-20.2021. Epub 2021 Mar 4.
We used a semantic feature-matching task combined with multivoxel pattern decoding to test contrasting accounts of the role of the default mode network (DMN) in cognitive flexibility. By one view, DMN and multiple-demand cortex have opposing roles in cognition, with DMN and multiple-demand regions within the dorsal attention network (DAN) supporting internal and external cognition, respectively. Consequently, while multiple-demand regions can decode current goal information, semantically relevant DMN regions might decode conceptual similarity regardless of task demands. Alternatively, DMN regions, like multiple-demand cortex, might show sensitivity to changing task demands, since both networks dynamically alter their patterns of connectivity depending on the context. Our task required human participants (any sex) to integrate conceptual knowledge with changing task goals, such that successive decisions were based on different features of the items (color, shape, and size). This allowed us to simultaneously decode semantic category and current goal information using whole-brain searchlight decoding. As expected, multiple-demand cortex, including DAN and frontoparietal control network, represented information about currently relevant conceptual features. Similar decoding results were found in DMN, including in angular gyrus and posterior cingulate cortex, indicating that DMN and multiple-demand regions can support the same function rather than being strictly competitive. Semantic category could be decoded in lateral occipital cortex independently of task demands, but not in most regions of DMN. Conceptual information related to the current goal dominates the multivariate response within DMN, which supports flexible retrieval by modulating its response to suit the task demands, alongside regions of multiple-demand cortex. We tested contrasting accounts of default mode network (DMN) function using multivoxel pattern analysis. By one view, semantically relevant parts of DMN represent conceptual similarity, regardless of task context. By an alternative view, DMN tracks changing task demands. Our semantic feature-matching task required participants to integrate conceptual knowledge with task goals, such that successive decisions were based on different features of the items. We demonstrate that DMN regions can decode the current goal, as it is applied, alongside multiple-demand regions traditionally associated with cognitive control, speaking to how DMN supports flexible cognition.
我们使用语义特征匹配任务结合多体素模式解码来测试默认模式网络（DMN）在认知灵活性中的作用的对比理论。根据一种观点，DMN 和多需求皮层在认知中具有相反的作用，DMN 和背侧注意网络（DAN）中的多个需求区域分别支持内部和外部认知。因此，虽然多需求区域可以解码当前目标信息，但语义相关的 DMN 区域可能会解码概念相似性，而不管任务需求如何。或者，DMN 区域可能像多需求皮层一样对不断变化的任务需求敏感，因为这两个网络都根据上下文动态改变它们的连接模式。我们的任务要求人类参与者（任何性别）将概念知识与不断变化的任务目标相结合，以便连续的决策基于项目的不同特征（颜色、形状和大小）。这使我们能够使用全脑搜索光解码同时解码语义类别和当前目标信息。不出所料，多需求皮层，包括 DAN 和额顶控制网络，代表了与当前相关概念特征的信息。在 DMN 中也发现了类似的解码结果，包括在角回和后扣带回皮层，表明 DMN 和多需求区域可以支持相同的功能，而不是严格竞争。语义类别可以在不需要任务的情况下在外侧枕叶皮层中解码，但在大多数 DMN 区域中则不能。与当前目标相关的概念信息在 DMN 内的多元反应中占主导地位，这通过调节其对任务需求的反应来支持灵活的检索，与多需求皮层区域一起。我们使用多体素模式分析测试了默认模式网络（DMN）功能的对比理论。根据一种观点，DMN 的语义相关部分代表概念相似性，而不管任务上下文如何。根据另一种观点，DMN 跟踪不断变化的任务需求。我们的语义特征匹配任务要求参与者将概念知识与任务目标相结合，以便连续的决策基于项目的不同特征。我们证明 DMN 区域可以解码当前目标，因为它是应用的，以及与认知控制传统相关的多需求区域，说明 DMN 如何支持灵活的认知。
