Non-Target Emotional Stimuli Must Be Highly Conspicuous in Order to Break through the Attentional Blink

In the attentional blink (AB), the second of two targets (T2) separated by a short lag in a rapid serial visual presentation (RSVP) stream is difficult to report. The AB is typically thought of as a top-down effect because it is triggered when the first target (T1) matches a search template. However, the AB is modulated when either target has emotional valence, and an AB-like effect can be triggered when a task-irrelevant but valenced critical distractor item (CDI) replaces T1. Neither target nor CDI valence manipulations fully captures the interplay between bottom-up and top-down attention in the AB. The valenced-target approach intrinsically conflates top-down and bottom-up attention. The CDI approach does not manipulate final-target valence, which is critical because such a manipulation can cause a target to “break through” the AB (in the target-manipulation approach). The novel approach of the present research resolves this methodological challenge by indirectly measuring whether a purely bottom-up CDI can break through the AB. This is accomplished by adding a valenced CDI to the “classic,” two-target AB. Participants viewed RSVP streams containing a T1-CDI pair followed by a variable lag and then T2. If the CDI’s emotional valence is sufficient to break through the AB, T2 performance should be modulated by CDI valence, yielding an indirect signal of bottom-up capture by emotional stimuli. Results demonstrated that CDI valence only affects the AB when CDIs are also extremely visually conspicuous. Thus, emotional valence alone is insufficient to break through the AB.