title: Prefrontal responses to Stroop tasks in subjects with post-traumatic stress disorder assessed by functional near infrared spectroscopy.
abstract: Studies on posttraumatic stress disorder (PTSD) showing attentional deficits have implicated abnormal activities in the frontal lobe. In this study, we utilized multichannel functional near-infrared spectroscopy (fNIRS) to investigate selective attention-related hemodynamic activity in the prefrontal cortex among 15 combat-exposed war-zone veterans with PTSD and 13 age- and gender-matched healthy controls. While performing the incongruent Stroop task, healthy controls showed significant activations in the left lateral prefrontal cortex (LPFC) compared to baseline readings. This observation is consistent with previously reported results. In comparison, subjects with PTSD failed to activate left LPFC during the same Stroop task. Our observations may implicate that subjects with PTSD experienced difficulty in overcoming Stroop interference. We also observed significant negative correlation between task reaction times and hemodynamic responses from left LPFC during the incongruent Stroop task in the PTSD group. Regarding the methodology used in this study, we have learned that an appropriate design of Stroop paradigms is important for meeting an optimal cognitive load which can lead to better brain image contrasts in response to Stroop interference between healthy versus PTSD subjects. Overall, the feasibility of fNIRS for studying and mapping neural correlates of selective attention and interference in subjects with PTSD is reported.
authors.affiliation: The University of Texas at Arlington, Department of Bioengineering, Arlington, TX 76019, USA.
authors.forename: Amarnath
authors.initials: A
authors.lastname: Yennu
authors.affiliation: The University of Texas at Arlington, Department of Bioengineering, Arlington, TX 76019, USA.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Tian
authors.affiliation: The University of Texas at Arlington, School of Social Work, Arlington, TX 76019, USA.
authors.forename: Alexa
authors.initials: A
authors.lastname: Smith-Osborne
authors.affiliation: The University of Texas at Arlington, Department of Psychology, Arlington, TX 76019, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: J Gatchel
authors.affiliation: The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Fu Lye
authors.initials: FL
authors.lastname: Woon
authors.affiliation: The University of Texas at Arlington, Department of Bioengineering, Arlington, TX 76019, USA.
authors.forename: Hanli
authors.initials: H
authors.lastname: Liu
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D004644:Emotions / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*; D057190:Stroop Test