Bipartite functional fractionation within the default network supports disparate forms of internally oriented cognition

Chiou, Rocco; Humphreys, Gina F.; Ralph, Matthew A. Lambon

doi:10.1101/864603

Cited by 6 publications

(21 citation statements)

References 62 publications

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“…Our results allow us to reject accounts of the neural basis of semantic cognition that anticipate strong functional dissimilarities between DMN and MDN in all circumstances. For example, the observation that DMN tends to deactivate during demanding tasks and the deactivation is positively associated behaviour performance (Anticevic et al, 2012) has motivated the proposal that DMN is not critical for controlled cognition (Shapira-Lichter et al, 2013;Axelrod et al, 2017), or for tasks that involve attending to external inputs (even when these tasks require conceptual processing) (Chiou et al, 2020). Our findings are clearly incompatible with these views.…”

Section: Discussioncontrasting

confidence: 62%

“…A recent study found that "core" DMN regions (e.g. angular gyrus and posterior cingulate cortex) show more task-related deactivation and selective recruitment for 'internal cognition', compared with lateral temporal DMN regions implicated in semantic processing (Chiou et al, 2020). By this view, the task-negative and controlled memory accounts of DMN can be reconciled by attributing these patterns of functional recruitment to different DMN subsystems.…”

Section: Discussionmentioning

confidence: 99%

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Both default and multiple-demand regions represent semantic goal information

Wang

Gao

Smallwood

et al. 2020

Preprint

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AbstractWhile the multiple-demand network plays an established role in cognitive flexibility, the role of default mode network is more poorly understood. In this study, we used a semantic feature matching task combined with multivoxel pattern decoding to test contrasting functional accounts. By one view, default mode and multiple-demand networks have opposing roles in cognition; consequently, while multiple-demand regions can decode current goal information, semantically-relevant default network regions might decode conceptual similarity irrespective of task demands. Alternatively, default mode regions might show sensitivity to changing task demands like multiple-demand regions, consistent with evidence that both networks dynamically alter their patterns of connectivity depending on the context. Our task required participants to integrate conceptual knowledge with changing task goals, such that successive decisions were based on different features of the items (colour, shape and size). This allowed us to simultaneously decode semantic category and current goal information using a whole-brain searchlight decoding approach. As expected, multiple-demand regions represented information about the currently-relevant conceptual feature, yet similar decoding results were found in default mode network regions, including angular gyrus and posterior cingulate cortex. Semantic category irrespective of task demands could be decoded in lateral occipital cortex, but not in most regions of default mode network. These results show that conceptual information related to the current goal dominates the multivariate response within default mode network. In this way, default mode network nodes support flexible memory retrieval by modulating their response to suit active task goals, alongside regions of multiple-demand cortex.Significance StatementWe tested contrasting accounts of default mode network (DMN) function using multivoxel pattern analysis. By one view, semantically-relevant parts of DMN represent conceptual similarity, irrespective 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 current goal, alongside multiple-demand regions traditionally associated with cognitive control. The successful decoding of goal information plus largely absent category decoding effects within DMN indicates that this network supports flexible semantic cognition.

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Section: Discussioncontrasting

confidence: 62%

Section: Discussionmentioning

confidence: 99%

Both default and multiple-demand regions represent semantic goal information

Wang

Gao

Smallwood

et al. 2020

Preprint

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“…Other DMN regions in the core as opposed to the lateral temporal subnetwork are equally distant from sensory-motor regions along the principal gradient and yet show differences in their responsiveness to tasks. Chiou et al (2020) suggested that core DMN regions show deactivation during externallyfocussed tasks, while lateral temporal regions show engagement. We show that lateral temporal DMN activates in response to meaningful visual inputs (sentences versus letter strings), even when this input is irrelevant to the ongoing task, and irrespective of task focus.…”

Section: Discussionmentioning

confidence: 99%

“…Recent research has proposed that internal cognitive states and externally oriented semantic tasks might activate distinct functional subdivisions within DMN (Andrews-Hanna et al 2010;Chiou et al 2020). Patterns of intrinsic connectivity within DMN point to separable subsystems (Andrews-Hanna et al 2010;Yeo et al 2011), focussed on (i) regions of lateral temporal cortex and anterior frontal gyrus, implicated in the representation and retrieval of conceptual knowledge (e.g., Badre and Wagner 2002;Jackson et al 2016;Lambon Ralph et al 2017), henceforth referred to as the "lateral temporal subsystem" here; (ii) medial temporal regions, such as hippocampus, that are important for episodic memory (Nyberg, McIntosh, et al 1996;Steinvorth et al 2005), termed as the "medial temporal subsystem"; and (iii) a "core" DMN subsystem drawing on posterior cingulate cortex, medial prefrontal cortex, and angular gyrus (AG), which might allow information to be transferred between these subsystems (Andrews-Hanna et al 2010;Andrews-Hanna, Smallwood, et al 2014) and which might correspond to interdigitated connectivity patterns to lateral and medial temporal subsystems (Braga and Buckner 2017;Braga et al 2019).…”

Section: Introductionmentioning

confidence: 99%

“…Patterns of intrinsic connectivity within DMN point to separable subsystems (Andrews-Hanna et al 2010;Yeo et al 2011), focussed on (i) regions of lateral temporal cortex and anterior frontal gyrus, implicated in the representation and retrieval of conceptual knowledge (e.g., Badre and Wagner 2002;Jackson et al 2016;Lambon Ralph et al 2017), henceforth referred to as the "lateral temporal subsystem" here; (ii) medial temporal regions, such as hippocampus, that are important for episodic memory (Nyberg, McIntosh, et al 1996;Steinvorth et al 2005), termed as the "medial temporal subsystem"; and (iii) a "core" DMN subsystem drawing on posterior cingulate cortex, medial prefrontal cortex, and angular gyrus (AG), which might allow information to be transferred between these subsystems (Andrews-Hanna et al 2010;Andrews-Hanna, Smallwood, et al 2014) and which might correspond to interdigitated connectivity patterns to lateral and medial temporal subsystems (Braga and Buckner 2017;Braga et al 2019). A functional dissociation across DMN subsystems was reported by Chiou et al (2020) who found the lateral temporal DMN subsystem prefers mental activities "interfacing with" perceptible events, while the core DMN prefers activities "detached from" perceptible events. Therefore, in the case of semantic cognition, it may be that the lateral temporal subsystem supports semantic tasks (as ATL within this subsystem, for example, is often activated by semantic content but deactivated by non-semantic tasks), while the core DMN subsystem may be disengaged by perceptually coupled semantic processing (e.g., core DMN areas in AG are consistently deactivated by semantic tasks, although may still show greater deactivation for nonsemantic tasks) (Humphreys et al 2015).…”

Section: Introductionmentioning

confidence: 99%

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Perceptual coupling and decoupling of the default mode network during mind-wandering and reading

Zhang

Bernhardt

Wang

et al. 2020

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Semantic cognition can be both perceptually-coupled, for example, during reading, and decoupled, such as in daydreams. Mind-wandering, characterised by autobiographical memory retrieval, often interferes with externally-focussed tasks. This study investigated the neural basis of these states, when they occur in isolation and in competition, using fMRI. Participants were asked to read sentences, presented word-by-word, or to recall personal memories, as a proxy for mind-wandering. Task conflict was created by presenting sentences during memory recall, or memory cues before sentences. We found that different subsystems of the default mode network (DMN) do not fully dissociate across internally- and externally-oriented states, and they do not fully separate in terms of the effects of task focus; this depends on the task. The lateral temporal DMN subsystem, associated with semantic cognition, was activated across both tasks, and by sentence inputs even when they were task-irrelevant. In the core DMN subsystem, greater task focus corresponded to a selective pattern of activation during memory recall and deactivation during reading. Both DMN subsystems formed different patterns of functional coupling depending on the task. In this way, DMN supports both access to meaning from perceptual inputs and focussed internal cognitive states in the face of distracting external information.

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Bipartite functional fractionation within the neural system for social cognition supports the psychological continuity of selfvs.other

Chiou

Cox

Ralph

2021

Preprint

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In the present study, we integrated two crucial issues in cognitive neuroscience: (i) The field of brain connectome research has been characterising the fine-grained fractionation within of each identified functional network. (ii) The field of social neuroscience has been exploring how a network of social-affective cortical zones implement the representational codes to idiosyncratically represent personal identities. Here we performed a series of multivoxel decoding to investigate the neural representations of self- vs. other-referential concept, a pivotal psychological construct that permeates every aspects of social life and has been argued as a core function of the specialised system for social cognition. Across multiple analyses, we found a robust dyadic fractionation between the two subnetworks within the social system - multivoxel patterns reliably dissociated between regions that are affiliated with the 'default mode' network and those with the 'semantic cognition' network, evident both in the outcomes of supervised classification and representational similarity. Moreover, representational configuration of the neural responses to self- and other-referential thoughts mirrored the psychological continuum of social distance, from an integral sense of one's present self to a distant other, with the broad-stroke distinction of 'self-ness vs. otherness' being the principal axis in the representational space, and social distance being the auxiliary axis. Taken together, our findings inform the burgeoning endeavour of connectome research about brain's network architecture and how it impacts on social cognition.

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Bipartite functional fractionation within the default network supports disparate forms of internally oriented cognition

Cited by 6 publications

References 62 publications

Both default and multiple-demand regions represent semantic goal information

Both default and multiple-demand regions represent semantic goal information

Perceptual coupling and decoupling of the default mode network during mind-wandering and reading

Bipartite functional fractionation within the neural system for social cognition supports the psychological continuity of selfvs.other

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