Default mode network can support the level of detail in experience during active task states

Mladen Sormaz*, Charlotte Murphy, Hao Ting Wang, Mark Hymers, Theodoros Karapanagiotidis, Giulia Poerio, Daniel S. Margulies, Elizabeth Jefferies, Jonathan Smallwood

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Regions of transmodal cortex, in particular the default mode network (DMN), have historically been argued to serve functions unrelated to task performance, in part because of associations with naturally occurring periods of off-task thought. In contrast, contemporary views of the DMN suggest it plays an integrative role in cognition that emerges from its location at the top of a cortical hierarchy and its relative isolation from systems directly involved in perception and action. The combination of these topographical features may allow the DMN to support abstract representations derived from lower levels in the hierarchy and so reflect the broader cognitive landscape. To investigate these contrasting views of DMN function, we sampled experience as participants performed tasks varying in their working-memory load while inside an fMRI scanner. We used self-report data to establish dimensions of thought that describe levels of detail, the relationship to a task, the modality of thought, and its emotional qualities. We used representational similarity analysis to examine correspondences between patterns of neural activity and each dimension of thought. Our results were inconsistent with a task-negative view of DMN function. Distinctions between on- and off-task thought were associated with patterns of consistent neural activity in regions adjacent to unimodal cortex, including motor and premotor cortex. Detail in ongoing thought was associated with patterns of activity within the DMN during periods of working-memory maintenance. These results demonstrate a contribution of the DMN to ongoing cognition extending beyond task-unrelated processing that can include detailed experiences occurring under active task conditions.

Original languageEnglish
Pages (from-to)9318-9323
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number37
Early online date27 Aug 2018
DOIs
Publication statusPublished - 11 Sept 2018

Bibliographical note

Copyright © 2018 the Author(s). Published by PNAS.

Keywords

  • Default model network
  • Mind wandering
  • Principal gradient
  • Representational similarity analysis
  • Humans
  • Male
  • Memory, Short-Term/physiology
  • Emotions/physiology
  • Motor Cortex/physiology
  • Adolescent
  • Adult
  • Female
  • Cognition/physiology
  • Nerve Net/physiology

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