Task-Irrelevant Threatening Information Is Harder to Ignore Than Other Valences

Abstract

Emotionally salient objects activate the survival circuits of the brain and are given priority in cognitive processing, even at the cost of inhibiting ongoing activities. These circuits arouse and prepare the organism to take swift action when needed. Previous studies have suggested, however, that not all emotional dimensions are equally prioritized. Threatening stimuli may have greater prominence than other emotional categories. Thus, we sought to compare the effects that stimuli of varying emotions would have on orienting and executive attentional processing. We performed two experiments to broaden our understanding of the attentional consequences of threats through the monitoring of participants’ eye movements. Participants were exposed to emotionally charged (threatening, nonthreatening negative, positive) and neutral pictures as task-irrelevant distractors while performing a primary visual search task (under conditions of varying cognitive load). Behavioural results showed that participants found the first target number more slowly when the distractor image was threatening, but overall task completion times were actually speeded in this condition (relative to other valences). Further, participants fixated on threatening distractor images earlier and observed them longer than other valences. Results were more pronounced when the primary task was harder. These biases were not evident for positive and nonthreatening images, presumably because participants were able to ignore them, providing further support to the contention that threatening stimuli hold greater prominence than other emotional categories. Together, our results are in line with previous studies suggesting that the processing of threatening stimuli is speeded, potentially because of differences in the brain circuits involved.