Negative expectancies in posttraumatic stress disorder: Neurophysiological (N400) and behavioral evidence

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Abstract

Background

Posttraumatic stress disorder (PTSD) is a disorder that theoretically and clinically is thought to be associated with persistent and exaggerated negative expectancies. This study used the N400 event-related potential (ERP) to investigate expectancies for threatening endings to ambiguous sentence stems. The N400 ERP is thought to reflect the amount of effort required to integrate a stimulus into a given context. In sentence reading tasks, the N400 is reliably larger when a word is unexpected.

Method

In this study, fifty-seven trauma survivors of various types (22 with PTSD and 35 without) read ambiguous sentence stems on a computer screen. These sentence stems were completed with either an expected (“The unfortunate man lost his…wallet”), unexpected (“The unfortunate man lost his…artist”), or threatening word endings (“The unfortunate man lost his…leg”).

Results

Participants with PTSD, as compared to those without, showed significantly smaller N400s to threatening sentence endings suggesting enhanced expectancies for threat. Behavioral responses supported this conclusion.

Conclusions

These findings are consistent with the clinical presentation of hypervigilance and proposed revisions to the DSM-V that emphasize persistent and exaggerated negative expectations about one's self, others, or the world. Relative to earlier behavioral studies, this work further suggests that this expectancy bias occurs automatically and at the early stages of information processing. The discussion focuses on the potential impact of a negative expectancy bias in PTSD and the value of the ambiguous sentence paradigm for studying PTSD as well as other disorders.

Section snippets

Participants

Participants for this study were recruited from the community using flyers and newspaper ads placed around Addison, Chittenden and Rutland counties in Vermont. Flyers were posted at local stores and businesses, and American Legion centers within a 50-mile radius of Middlebury College and Norwich University. The flyers and advertisements provided basic information about the study, including monetary compensation for participation, and instructed interested individuals to contact the principle

Behavioral data

On 99.0% of the congruent trials, participants pressed the “Yes” button indicating that the expected final words made sense. Participants pressed “Yes” only 11.6% of the time on unexpected trials. On threatening trials, participants pressed “Yes” on 84.8% of the trials. A 2 (PTSD) × 3 (Condition) ANOVA indicated a PTSD × Condition interaction [F(2,53) = 10.81, p < .01] with the two groups differing only in how they responded to the threatening final words [t(55) = 5.33, p < .01]. Those with

Overview

The purpose of this study was to investigate possible neurophysiological evidence consistent with theoretical and clinical models of biases in individuals with PTSD. It was hypothesized that compared to individuals without PTSD, those with PTSD would exhibit smaller N400 amplitudes in response to threatening sentence endings due to their increased expectancies for threatening information. Consistent with the hypothesis, individuals with PTSD showed smaller (less negative) N400s in response to

Role of funding source

This publication was made possible by the Vermont Genetics Network through Grant # P20 RR16462 from the IMBRE Program of the National Center for Research Resources (NCRR) and component of the NIH as well as an AREA grant (R15 MH 081276) from the National Institute of Mental Health. Neither agency had further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.

Contributors

Laura Batterink, Libby Marks, and Cordelia Ross all collected substantial portions of the data, analyzed subsets of the data, did careful literature reviews, and wrote academic theses on parts of the project. Kevin Fleming played an important role in the creation of the task, the discussion of theoretical issues, and consultation regarding interpretation and analyses.

Conflict of interest

All authors declare that they have no conflicts of interest.

Acknowledgments

I would like to thank Jason Arndt for his feedback on design and methodology and Mariam Boxwala for her assistance in preparing the manuscript.

References (51)

  • A. Karl et al.

    Negative self-appraisals in treatment-seeking survivors of motor vehicle accidents

    Journal of Anxiety Disorders

    (2009)
  • M. Kiang et al.

    Electrophysiological insights into conceptual disorganization in schizophrenia

    Schizophrenia Research

    (2007)
  • M.O. Kimble et al.

    Sentence completion test in combat veterans with and without PTSD: preliminary findings

    Psychiatry Research

    (2002)
  • M.O. Kimble et al.

    Does the modified stroop effect exist in PTSD? Evidence from dissertation abstracts and the peer reviewed literature

    Journal of Anxiety Disorders

    (2009)
  • M. Kutas et al.

    Electrophysiology reveals semantic memory use in language comprehension

    Trends in Cognitive Science

    (2000)
  • J.S. Moser et al.

    Posttraumatic stress disorder symptoms in trauma-exposed college students: the role of trauma-related cognitions, gender, and negative affect

    Journal of Anxiety Disorders

    (2007)
  • D.F. Salisbury et al.

    Semantic bias, homograph comprehension, and event-related potentials in schizophrenia

    Clinical Neurophysiology

    (2002)
  • K. Smith et al.

    The generality of cognitive bias in acute stress disorder

    Behavior Research and Therapy

    (2000)
  • C. Van Petten et al.

    Conceptual relationships between spoken words and environmental sounds: event-related brain potential measures

    Neuropsychologia

    (1995)
  • G. Warda et al.

    Cognitive bias in acute stress disorder

    Behavior Research and Therapy

    (1998)
  • M. Weisbrod et al.

    Electrophysiological correlates of direct versus indirect semantic priming in normal volunteers

    Cognitive Brain Research

    (1999)
  • E. Agar et al.

    The role of negative cognitive appraisals in PTSD symptoms following spinal cord injuries

    Behavioural and Cognitive Psychotherapy

    (2006)
  • American Psychiatric Association

    Diagnostic and statistical manual of mental disorders

    (2000)
  • Y. Bar-Haim

    Research review: attention bias modification (ADM): a novel treatment for anxiety disorders

    Journal of Child Psychology and Psychiatry

    (2010)
  • Y. Bar-Haim et al.

    Threat-related attentional bias in anxious and nonanxious individuals: a meta-analytic study

    Psychological Bulletin

    (2007)
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