title: Central Executive Dysfunction and Deferred Prefrontal Processing in Veterans with Gulf War Illness.
abstract: Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central executive of WM. A large sample of GWIPs and matched controls (MCs) underwent functional magnetic resonance imaging during a varied-load working memory task. Compared to MCs, GWIPs showed a greater decline in performance as WM-demand increased. Functional imaging suggested that GWIPs evinced separate processing strategies, deferring prefrontal cortex activity from encoding to retrieval for high demand conditions. Greater activity during high-demand encoding predicted greater WM performance. Behavioral data suggest that WM executive strategies are impaired in GWIPs. Functional data further support this hypothesis and suggest that GWIPs utilize less effective strategies during high-demand WM.
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Hubbard
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Hutchison
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Motes
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Shokri-Kojori
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Ilana J
authors.initials: IJ
authors.lastname: Bennett
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Brigante
authors.affiliation: Epidemiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Haley
authors.affiliation: School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Bart
authors.initials: B
authors.lastname: Rypma