Abstract
Emotion-induced blindness (EIB) refers to impaired awareness for items appearing soon after an irrelevant, emotionally arousing stimulus. In previous research we analyzed the mechanisms responsible for EIB using event-related brain potentials (ERPs). Participants searched rapidly presented streams of pictures (landscapes and cityscapes) for a target, which was a scene picture rotated 90 degrees left or right. Each stream also contained an irrelevant "distractor" picture that could be emotionally negative (dangerous animals, mutilated bodies, etc.) or neutral (people and animals in nonemotional settings). When the irrelevant negative picture preceded the target by two pictures, target discrimination was severely impaired. A smaller impairment emerged following neutral distractors. We discovered two ERP components related to the magnitude of this suppression: the N2 and the Pd. The N2, which is thought to reflect attentional engagement, was larger in response to Negative than to Neutral distractors, while Scenes produced no discernible N2. Thus, the amplitude of the N2 elicited by a distractor was related to its ability to suppress a subsequent target. A similar relationship was observed for the Pd component, which follows the N2 and is thought to reflect attentional disengagement. The current research addresses the following question: Are these differences between neutral and negative distractors due to differences in valence or to uncontrolled differences in physical salience? We examined this issue by using pairs of neutral and negative distractor pictures that were chosen and/or manipulated to maximize their physical similarity to each other. Although this manipulation eliminated the difference in N2 amplitude, negative distractors continued to cause greater EIB than did neutral pictures, and they continued to elicit larger Pd components. These results suggest that the N2 may be related to physical salience but that this factor does not fully account for perceptual impairments caused by emotionally negative, relative to neutral, distractors.
Meeting abstract presented at VSS 2013