Increasing cognitive load attenuates the moderating effect of attentional inhibition on the relationship between posttraumatic stress symptoms and threat-related attention bias variability.

Theory and empirical evidence suggest that those with higher posttraumatic stress (PTS) symptoms and better attentional control (i.e., the strategic control of higher-order executive attention in regulating bottom-up, stimulus driven responses to prepotent stimuli; Sarapas et al., 2017) can use that ability to disengage and shift attention away from threat stimuli and reduce threat-related attentional dysregulation (i.e., avoidance/overcontrollers). Those with relatively worse attentional control lack the requisite resources to do this, leading to prolonged attentional engagement with threat stimuli and threat-related attention dysregulation (i.e., maintenance/undercontrollers). Given that attentional control is a limited resource, strategic avoidance of threat information or reduced threat-related attention dysregulation may not be possible among those with relatively higher attentional control when cognitive load is relatively high. To test this hypothesis, the interaction between PTS symptoms, attentional control, and cognitive load was examined as a predictor of threat-related attentional bias and threat-related attention bias variability. Participants (N = 125 undergraduate students) were randomly assigned to high or low load conditions. Participants completed self-report measures of PTS symptoms, a behavioral measure of attentional control, and a novel task that assessed threat-related attentional bias via eye movements and threat-related attention bias variability via button press. The results of a series of hierarchical regressions showed that attentional control moderated the relationship between PTS symptoms and threat-related attention bias variability in the low, but not high, load condition. This moderation effect was not observed for threat-related attentional bias assessed via eye-tracking. Consistent with theory, under conditions of higher cognitive load, overcontrollers may not be able to use attentional control to consistently regulate threat-related attention. Study findings suggest that it may be important to consider contextual factors that increase cognitive load, as well as individual differences in attentional control, when developing attention bias modification interventions to reduce PTS symptomatology.