Rejecting emotional distractors: experience-mediated attentional learning and motivational relevance

Survival depends on the ability to rapidly detect emotionally significant stimuli, and adapt one's behavior accordingly. When an emotional stimulus occurs, attention is involuntarily diverted to it, causing a disruption in performance in a concurrent task. Emotional distractors not only capture attention but also engage cortico-limbic motivational systems. In terms of cortical responses, it is well established that emotional pictures elicit a larger late positive potential (LPP) than neutral ones. The behavioral interference and emotional modulation of the LPP have been interpreted as evidence that emotional stimuli are prioritized in terms of perception, and that the engagement of motivational systems occurs automatically. However, few studies have examined whether we can learn to ignore constantly irrelevant emotional stimuli through direct experience. The current thesis examines the extent to which experience with task-irrelevant images modulates attentional capture by emotional pictures, and which stage of emotional processing is affected by distractor experience. In Experiment 1 (Experiments 1a and 1b), the role of distractor experience was examined in terms of distractor frequency, showing that frequent exposure to distracting images reduced the interference of novel (never repeated) emotional stimuli, even when they were rare, and consequently, highly significant. In line with this finding, Experiment 2 (Experiments 2a and 2b) provided evidence that practice with variable distracting images reduced the emotional interference effect. Conversely, the affective modulation of the LPP persisted despite the frequent occurrence of distractors and the prolonged exposure to distractors. Altogether these findings suggest that evaluative processes are mandatory, as suggested by the affective modulation of the LPP. However, observers can adaptively ignore irrelevant emotional stimuli after the evaluation process has occurred, indicating that the ability to overcome emotional attentional capture results directly from experience with distracting events, and depends, therefore, on the possibility to learn that such stimuli are inconsequential.