Cue-Driven Changes in Detection Strategies Reflect Trade-Offs in Strategic Efficiency

We examined performance in a cued detection task when a peripheral cue was either 50% or 100% valid, tested in separate experiments. We combined a Posner cueing task with a double factorial manipulation of stimulus salience. Unlike previous investigations in which participants responded to either target, we employed an AND decision task in which a target-present decision required there to be a target at both locations. When the cue was 50% valid, all the participants adopted parallel exhaustive processing to detect redundant targets with unlimited to limited capacity. When the cue was 100% valid, three participants, who performed this experiment first, adopted serial exhaustive processing. By contrast, the participants who first performed the 50% validity experiment continued to adopt parallel exhaustive processing. Capacity generally declined below a lower bound, suggesting extremely limited capacity. Our conclusion is that the validity of the cue affected processing strategy but participants could increase the relative efficiency of the parallel processing with practice.