Searching for emotional salience

In the emotion induced blindness (EIB) paradigm, participants search for a single target picture embedded in a rapidly presented sequence of “background” pictures. When the sequence also contains a task-irrelevant, emotional distractor appearing shortly before the target, awareness for the target is severely impaired (Most, Chun, Widders, & Zald, 2005). This temporary “blindness” for the target is thought to reflect attention capture by the emotionally salient distractor which blocks the target's access to the attention system. However, there are also reasons to suspect that physical salience may play an important role in the initial attention capture process. The emotional pictures consist of close-ups of people and animals while the background pictures are wide-angle views of landscapes and cityscapes. These physical differences might result in pop-out of the distractor picture that is at least partially based on physical and not emotional salience. We investigated the role of physical salience in emotional capture by comparing the typical EIB paradigm, which uses dissimilar distractors, with one in which the background pictures consist of people and animals in non-emotional settings (similar distractors). If emotional salience is the basis of attention capture in EIB, we should see similar amounts of target suppression in both conditions. Instead, we found that the EIB effect was reduced and possibly eliminated in the similar background condition. A control experiment revealed that emotional information was still available in the similar background condition because the blink was restored when the emotional picture was designated for report by a salient cue. These findings are clearly inconsistent with current theories of EIB (e.g., McHugo, Olatunji, & Zald, 2013) which assume that initial attention capture is driven by emotional not physical salience.