Modulating emotional bias in attentional competition

Abstract

Emotionally powerful stimuli can impair the awareness for other items presented in their temporal wake – a phenomenon known as emotion-induced blindness (EIB). EIB is believed to occur because of a spatiotemporally-driven competition, in which emotionally powerful distractors gain a competitive edge over task-relevant targets. The present study had two aims: (1) to verify a competition account of EIB, and (2) to investigate if and how the competitive edge of emotional distractors can be reduced, thereby benefitting target perception. The experiments in Chapter 1 tested whether eye-gaze might present an alternative explanation for the spatially localized nature of EIB. In an EIB task, targets that appear in the same spatial location as a preceding emotional distractor are poorly reported, but targets that appear in a different location are not. This spatially localized pattern of impairment supports a competition account for EIB, but could instead be explained simply by where participants look during the task. The experiments in Chapter 1 employed gaze-contingent eye-tracking and ruled out eye-gaze, supporting a spatiotemporal competition account for EIB. Chapter 2 provided evidence that the bias toward emotional distractors is not dependent on the context in which distractors appear. In Chapter 2, EIB was observed regardless of the distractors’ categorical similarity to other items in the stream. However, in Chapter 3, the bias toward emotional distractors did change based on the way participants regarded the task-relevance of distractors: participants exhibited greater EIB when they considered the distractor to be task-relevant rather than task-irrelevant. In Chapter 4, the competition was also modulated by proactive control: when participants were told the kind of emotional distractor to expect in a given trial, they were better able to overcome emotion-induced blindness. Taken together, the experiments in this thesis supported a spatiotemporal competition account of emotion-induced blindness and demonstrated that the competition between emotional distractors and task-relevant targets can be modulated in an emotion-induced blindness paradigm. This work provides insight into the mechanisms involved in emotion-induced blindness and identifies ways that emotional distraction may be overcome.