Proactive Control of Emotional Distraction: An ERP Investigation

According to the Dual Mechanisms of Control (DMC) framework (Braver, 2012) distraction can be controlled either proactively (i.e., before the onset of a distractor) or reactively (i.e., after the onset of a distractor). Research clearly indicates that, when distractors are emotionally neutral, proactive mechanisms are more effective at controlling distraction than reactive mechanisms. However, whether proactive control mechanisms can control irrelevant emotional distractions as effectively as neutral distraction is not known. In the current thesis I examined cognitive control over emotional distraction. In Experiment 1, I tested whether proactive mechanisms can control emotional distraction as effectively as neutral distraction. Participants completed a distraction task. On each trial, they determined whether a centrally presented target letter (embedded amongst a circle of ‘o’s) was an ‘X’ or an ‘N’, while ignoring peripheral distractors (negative, neutral, or positive images). Distractors were presented on either a low proportion (25%) or a high proportion (75%) of trials, to evoke reactive and proactive cognitive control strategies, respectively. Emotional images (both positive and negative) produced more distraction than neutral images in the low distractor frequency (i.e., reactive control) condition. Critically, emotional distraction was almost abolished in the high distractor frequency condition; emotional images were only slightly more distracting than neutral images, suggesting that proactive mechanisms can control emotional distraction almost as effectively as neutral distraction. In Experiment 2, I replicated and extended Experiment 1. ERPs were recorded while participants completed the distraction task. An early index (the early posterior negativity; EPN) and a late index (the late positive potential; LPP) of emotional processing were examined to investigate the mechanisms by which proactive control minimises emotional distraction. The behavioural results of Experiment 2 replicated Experiment 1, providing further support for the hypothesis that proactive mechanisms can control emotional distractions as effectively as neutral distractions. While proactive control was found to eliminate early emotional processing of positive distractors, it paradoxically did not attenuate late emotional processing of positive distractors. On the other hand, proactive control eliminated late emotional processing of negative distractors. However, the early index of emotional processing was not a reliable index of negative distractor processing under either reactive or proactive conditions. Taken together, my findings show that proactive mechanisms can effectively control emotional distraction, but do not clearly establish the mechanisms by which this occurs