On the Timing of Overt Attention Deployment: Eye-Movement Evidence for the Priority Accumulation Framework

Most visual-search theories assume that our attention is automatically allocated to the location with the highest priority at any given moment. The Priority Accumulation Framework (PAF) challengesthis assumption. It suggests that the priority weight at each location accumulates across sequential events and that evidence for the presence of action-relevant information contributes to determining when attention is deployed to the location with the highest accumulated priority. Here, we tested these hypotheses for overt attention by recording first saccades in a free-viewing spatial-cueing task. We manipulated search difficulty (Experiments 1 and 2) and cue salience (Experiment 2). Standard theories posit that when oculomotor capture by the cue occurs, it is initiated before the search display appears; therefore, these theories predict that the cue’s impact on the distribution of first saccades should be independent of search difficulty but influenced by the cue’s saliency. By contrast, PAF posits that the cue can bias competition later, after processing of the search display has already started, and therefore predicts that such late impact should increase with both search difficulty and cue salience. The results fully supported PAF’s predictions. Our account suggests a distinction between attentional capture and attentional-priority bias that resolves enduring inconsistencies in the attentional-capture literature.