Can subliminal perception of negative pictures produce emotion-induced blindness?
Date
2013-05
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
Emotion-induced blindness (EIB) refers to impaired awareness for items that
appear soon after an irrelevant, emotionally arousing stimulus. Previous research
(Kennedy et al., 2012) that used event-related brain potentials (ERPs) to study the
mechanisms responsible for EIB found that emotional distractor pictures elicited two
ERP components that were related to the magnitude of EIB: the EPN, which is thought
to reflect attentional engagement, and the Pd, which appears to index attentional
disengagement. The current research investigates whether these components are
automatic or require attention. Previous research has produced mixed results on the
question of whether the EPN component elicited by negative pictures is affected by
attention while the Pd component has not been examined. We addressed the
automaticity of these components by requiring participants to perform a multiple
object tracking (MOT) task on objects moving in front of a stream of rapidly presented
pictures (outdoor scenes and cityscapes). Earlier research showed that MOT abolished
awareness for scene pictures appearing in a stream of distractors pictures (Cohen,
Alvarez, & Nakayama, 2011). The current experiment uses a similar paradigm to
study the impact of emotional “distractor” pictures that could be negative (dangerous
animals, mutilated bodies, etc.) or neutral (people and animals in non-emotional
settings). When observers attended to the picture stream, distractors produced robust
EPN and Pd components. In contrast, when observers performed the MOT task and
attempted to ignore the pictures, the EPN associated with distractors was diminished
while the Pd components increased in amplitude. These results show that the EPN component elicited by distractor pictures is sensitive to attention and is reduced when
attention is occupied by another task. In contrast, the Pd component is enhanced when
salient distractors are ignored which is consistent with the claim that this component
reflects a process responsible for preventing or terminating attentional engagement.