Cognitive Slowing in Gulf War Illness Predicts Executive Network Hyperconnectivity: Study in a Population-Representative Sample

Monroe P. Turner, Nicholas A. Hubbard, Lyndahl M. Himes, Shawheen Faghihahmadabadi, Joanna L. Hutchison, Ilana J. Bennett, Michael A. Motes, Robert W Haley, Bart Rypma

Research output: Contribution to journalArticle

4 Scopus citations


Cognitive slowing is a prevalent symptom observed in Gulf War Illness (GWI). The present study assessed the extent to which functional connectivity between dorsolateral prefrontal cortex (DLPFC) and other task-relevant brain regions was predictive of GWI-related cognitive slowing. GWI patients (n = 54) and healthy veteran controls (n = 29) were assessed on performance of a processing speed task (the Digit Symbol Substitution Task; DSST) while undergoing functional magnetic resonance imaging (fMRI). GWI patients were slower on the DSST relative to controls. Bilateral DLPFC connectivity with task-relevant nodes was altered in GWI patients compared to healthy controls during DSST performance. Moreover, hyperconnectivity in these networks predicted GWI-related increases in reaction time on the DSST, whereas hypoconnectivity did not. These results suggest that GWI-related cognitive slowing reflects reduced efficiency in cortical networks.

Original languageEnglish (US)
Pages (from-to)535-541
Number of pages7
JournalNeuroImage: Clinical
StatePublished - Jan 1 2016



  • Gulf War Illness
  • cognitive efficiency
  • dorsolateral prefrontal cortex
  • functional connectivity
  • functional magnetic resonance imaging
  • processing speed

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Clinical Neurology
  • Cognitive Neuroscience

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