The yellow light: Predictability enhances background processing during behaviorally relevant events.

The attentional boost effect refers to the observation that when simultaneously performing a scene memory task and a target detection task, participants better remember scenes that appear at the same time as the detection target than scenes that coincide with distractors. The attentional boost effect is thought to result from a transient increase in attention during an acute behaviorally relevant event, resulting from a temporal orienting response. But can endogenous orienting to predictable targets trigger this response in the same manner as exogenous orienting to unpredictable targets? Until now, the attentional boost effect has only been tested under conditions in which the target's appearance was unpredictable. Because of the distinction between exogenous and endogenous orienting, target predictability could attenuate the attentional boost effect, or it could increase temporal orienting efficiency and enhance the effect. To test the attentional boost effect under predictable conditions, participants memorized scenes while responding to a target digit, 0, among a stream of digits appearing in the center of those scenes. In some blocks, 0 the predictably followed the digit sequence 3-2-1. In these predictable blocks, participants showed a robust attentional boost effect. This shows that both endogenous orienting to temporally predictable targets and exogenous orienting to unpredictable targets enhance concurrent task processing.