Turning a blind eye: The struggle to inhibit attention towards unexpected negative emotions

We investigated whether expectations modulate the attentional capture of fearful and happy face distractors in a visual search task. Twenty-eight participants were instructed to locate a face surrounded by a color singleton and subsequently discriminate its gender. On some trials, the target was displayed concurrently with an irrelevant happy or fearful distractor. At the beginning of each block, instructions informed participants of the probability with which a happy or fearful distractor could occur. We measured lateralized event-related potentials time-locked to the irrelevant distractors and found that attentional suppression, indexed by the distractor positivity (P_D), was only present for fearful faces when they were unexpected. No voltage differences were found for expected/unexpected happy or expected fearful face distractors. These findings suggest that facial expressions affiliated with threat have a high attentional priority due to their emotional value but only when they are unexpected; if the presence of a threat is expected, the need for attentional capture-and thus attentional suppression-is mitigated. This raises questions regarding the assumed priority of threat in visual processing and the important role of an individual's expectations when interacting with threat in the environment.