Threat-Related Attentional Bias in PTSD: A Systematic Review and Meta-Analysis of Free-Viewing Eye-Tracking Studies

Abstract

Introduction: Cognitive and information processing theories of post-traumatic stress disorder (PTSD) posit that an attentional bias (AB) towards threat is a core mechanism of PTSD, contributing to the disorder's etiology and maintenance. Reaction time-based measures have been used to assess AB, but poor psychometric properties likely underlie their inconsistent findings. Utilization of eye-tracking technology during free-viewing paradigms overcomes these limitations. To date, eye-tracking evidence of an AB in PTSD is mixed and has not been quantitatively assessed. The objective of this meta-analysis is to clarify the presence of an AB towards general threat in PTSD.

Methods: The Ovid search tool was used to search PubMed, Embase, and APA PsycInfo databases. Studies were independently screened, and outcome data was extracted from included studies. Effect sizes were computed, and a random-effects linear model was used to pool effect sizes for both a PTSD vs. trauma-exposed healthy controls (TEHC) and PTSD vs. healthy controls (HC) comparison.

Results: After an outlier was removed from both comparisons, a small but statistically significant pooled effect emerged in the PTSD vs. TEHC comparison and heterogeneity was not statistically significant. In the PTSD vs. HC analysis, a moderate effect approaching significance was revealed with significant heterogeneity.

Discussion: Our results provide partial support for the presence of an AB towards general threat in PTSD. The majority of the variance in our analyses was due to variance in true effects, suggesting heterogeneous methodologies. The statistically significant PTSD vs. TEHC comparison suggests that an AB is characteristic of PTSD pathology rather than mere trauma exposure. Inconclusive results from the PTSD vs. HC comparison prompt further investigation.

Conclusion: This review provides additional context for cognitive models and information processing theories of PTSD. Longitudinal studies are needed to assess the role AB plays in the disorder’s manifestation and maintenance. Eye-tracking studies should incorporate standardized methods and assess other components of AB.