Task-dependent reorganization of functional connectivity networks during visual semantic decision making

Matthew N DeSalvo, Linda Douw, Shigetoshi Takaya, Hesheng Liu, Steven M Stufflebeam

Research output: Contribution to journalArticleAcademicpeer-review

34 Citations (Scopus)


INTRODUCTION: Functional MRI is widely used to study task-related changes in neuronal activity as well as resting-state functional connectivity. In this study, we explore task-related changes in functional connectivity networks using fMRI. Dynamic connectivity may represent a new measure of neural network robustness that would impact both clinical and research efforts. However, prior studies of task-related changes in functional connectivity have shown apparently conflicting results, leading to several competing hypotheses regarding the relationship between task-related and resting-state brain networks.

METHODS: We used a graph theory-based network approach to compare functional connectivity in healthy subjects between the resting state and when performing a clinically used semantic decision task. We analyzed fMRI data from 21 healthy, right-handed subjects.

RESULTS: While three nonoverlapping, highly intraconnected functional modules were observed in the resting state, an additional language-related module emerged during the semantic decision task. Both overall and within-module connectivity were greater in default mode network (DMN) and classical language areas during semantic decision making compared to rest, while between-module connectivity was diffusely greater at rest, revealing a more widely distributed pattern of functional connectivity at rest.

CONCLUSIONS: The results of this study suggest that there are differences in network topology between resting and task states. Specifically, semantic decision making is associated with a reduction in distributed connectivity through hub areas of the DMN as well as an increase in connectivity within both default and language networks.

Original languageEnglish
Pages (from-to)877-85
Number of pages9
JournalBrain and behavior
Issue number6
Publication statusPublished - 2014


  • Adult
  • Brain Mapping
  • Brain/physiology
  • Decision Making/physiology
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neural Pathways/physiology
  • Neuropsychological Tests
  • Rest
  • Retrospective Studies
  • Semantics
  • Signal Processing, Computer-Assisted
  • Visual Perception/physiology
  • Young Adult

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