This study aimed to investigate the time course of attentional bias for negative information in healthy individuals and to assess the associated influence of trait anxiety. Thirty-eight healthy volunteers performed an emotional dot-probe task with pairs of negative and neutral scenes, presented for either 1 or 2 s and followed by a target placed at the previous location of either negative or neutral stimulus. Analyses included eye movements during the presentation of the scenes and response times associated with target localization. In a second step, analyses focused on the influence of trait anxiety. While there was no significant difference at the behavioral level, the eye-tracking data revealed that negative information held longer attention than neutral stimuli once fixated. This initial maintenance bias towards negative pictures then increased with increasing trait anxiety. However, at later processing stages, only individuals with the highest trait anxiety appeared to fixate longer on negative pictures than neutral pictures, individuals with low trait anxiety showing the opposite pattern. This study provides novel evidence that healthy individuals display an attentional maintenance bias towards negative stimuli, which is associated with trait anxiety. Vision, like the other sensory systems, is constrained by its limited capacity of processing. Attention allows coping with this issue by selecting specific information within our rich and complex environment that will benefit from more elaborate processing and access to consciousness. The properties of the retina also constrain visual perception by limiting high-resolution processing to the fovea, which covers only the central 2° of visual angle. In naturalistic viewing, attentional selection relies on eye movements allowing to bring visual stimuli onto the fovea 1. Overt attention is functionally coupled to, and share neural mechanisms with 2-4 , covert attention that improves perception at a specific visual location without gaze reorienting but also guides eye movements 5-10. Attentional selection is also supposed to operate according to two complementary and interacting processes 11-14. The reflexive or exogenous attention is a fast, bottom-up (stimulus-driven) process that selects stimuli according to their physical features or because they are novel or unexpected. The voluntary or endogenous attention is a slower, top-down (goal-driven) process selecting stimuli that are expected or relevant to current goals. It is also increasingly recognized that emotionally laden stimuli, given their strong adaptive significance, benefit from preferential processing over neutral stimuli 15,16. The exact nature of the mechanisms responsible for this effect remains open to debate, in particular regarding the degree to which they differ from classical attention mechanisms 17,18. However, evidence suggests that "emotional attention" also involves a balance between bottom-up and top-down processes 17,19. The valence-related salience of a stimulus may thus depend on internal...

Background Research on biased processing of aversive stimuli in posttraumatic stress disorder (PTSD) has produced inconsistent results between response time (RT) and eye-tracking studies. Recent RT-based results of dot-probe studies showed no attentional bias (AB) for threat while eye-tracking research suggested heightened sustained attention for this information. Here, we used both RT-based and eye-tracking measures to explore the dynamics of AB to negative stimuli in PTSD. Methods Twenty-three individuals diagnosed with PTSD, 23 trauma-exposed healthy controls, and 23 healthy controls performed an emotional dot-probe task with pairs of negative and neutral scenes presented for either 1 or 2 s. Analyses included eye movements during the presentation of the scenes and RT associated with target localization. Results There was no evidence for an AB toward negative stimuli in PTSD from RT measures. However, the main eye-tracking results revealed that all three groups showed longer dwell times on negative pictures than neutral pictures at 1 s and that this AB was stronger for individuals with PTSD. Moreover, although AB disappeared for the two groups of healthy controls with prolonged exposure, it persisted for individuals with PTSD. Conclusion PTSD is associated with an AB toward negative stimuli, characterized by heightened sustained attention toward negative scenes once detected. This study sheds light on the dynamics of AB to negative stimuli in PTSD and encourages us to consider optimized therapeutic interventions targeting abnormal AB patterns.

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