Engagement with angry faces during attentional bias modification: Insights from the N2pc

Healthy individuals show an attentional bias toward threat, and this bias is exaggerated in anxious individuals. Recent studies have shown that training anxious individuals to attend to neutral information can reduce their threat bias and anxiety levels. This training is called attentional bias modification (ABM). However, despite the large literature on ABM, it is still unclear how ABM achieves its effects. Two mechanisms – facilitated engagement with threat, and delayed disengagement from threat – are thought to be involved in the threat bias. In this thesis, I investigated the effects of ABM on engagement with angry faces. First, in Experiment 1 I developed an ABM task to train healthy individuals to attend to either angry or neutral faces. Participants completed a dot-probe task in which they saw two faces – one angry and one neutral – followed by a target that appeared more often in the location of either the angry or neutral face (depending on their respective training condition). Experiment 1 was successful at inducing a bias. Next, Experiment 2 used this task to investigate the effects of ABM on event-related potentials before, during, and after training. The N2pc component, which provides a measure of attentional engagement, was used to investigate changes in engagement with angry and neutral faces as a function of training. Consistent with previous studies, there was an overall N2pc for the angry face, indicating that participants were engaging their attention with the angry face. However, the N2pc was not affected by training, even though participants were moving their eyes in the training-congruent direction during training, indicating sensitivity to the training contingency. These results suggest that ABM does not affect attentional engagement with threat stimuli. Rather, it is likely that an improved ability to disengage attention from threat stimuli underlies ABM’s training effects.