title: Atypical visual processing in posttraumatic stress disorder.
abstract: BACKGROUND
  Many patients with Posttraumatic Stress Disorder (PTSD) feel overwhelmed in situations with high levels of sensory input, as in crowded situations with complex sensory characteristics. These difficulties might be related to subtle sensory processing deficits similar to those that have been found for sounds in electrophysiological studies.
  
  
  METHODS
  Visual processing was investigated with functional magnetic resonance imaging in trauma-exposed participants with (N = 18) and without PTSD (N = 21) employing a picture-viewing task.
  
  
  RESULTS
  Activity observed in response to visual scenes was lower in PTSD participants 1) in the ventral stream of the visual system, including striate and extrastriate, inferior temporal, and entorhinal cortices, and 2) in dorsal and ventral attention systems (P < 0.05, FWE-corrected). These effects could not be explained by the emotional salience of the pictures.
  
  
  CONCLUSIONS
  Visual processing was substantially altered in PTSD in the ventral visual stream, a component of the visual system thought to be responsible for object property processing. Together with previous reports of subtle auditory deficits in PTSD, these findings provide strong support for potentially important sensory processing deficits, whose origins may be related to dysfunctional attention processes.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland ; Center of Education and Research (COEUR), Psychiatric Services of the County of St. Gallen-North, Wil, Switzerland ; Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mueller-Pfeiffer
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland.
authors.forename: Matthis
authors.initials: M
authors.lastname: Schick
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schulte-Vels
authors.affiliation: Center for MR-Research, University Children's Hospital, Zurich, Switzerland.
authors.forename: Ruth
authors.initials: R
authors.lastname: O'Gorman
authors.affiliation: Center for MR-Research, University Children's Hospital, Zurich, Switzerland ; Institute of Neuroradiology, University Hospital, Zurich, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Michels
authors.affiliation: Department of Clinical Psychology, University of Fribourg, Switzerland.
authors.forename: Chantal
authors.initials: C
authors.lastname: Martin-Soelch
authors.affiliation: Mood and Anxiety Disorders Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Blair
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Rufer
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital, Zurich, Switzerland.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schnyder
authors.affiliation: Neural Systems Group, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zeffiro
authors.affiliation: Psychiatric University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Gregor
authors.initials: G
authors.lastname: Hasler
keywords: Dorsal stream; International Affective Picture System; Sensory perception; Ventral stream; Visual system; fMRI