Modelling response selection in task switching: testing the contingent encoding assumption.

The contingent encoding assumption is the idea that response selection in task-switching situations does not begin until the cue and the target have both been encoded. The authors tested the assumption by manipulating response congruency, stimulus order, and stimulus onset asynchrony (SOA) in two experiments. They found evidence of response selection prior to cue encoding for congruent targets with target-cue order at a long SOA, indicating that the contingent encoding assumption is invalid. The authors describe how contingent encoding can be removed from an existing task-switching model by introducing baseline evidence--task-neutral evidence that serves as a baseline for response selection prior to stimulus encoding. Simulations revealed that the modified model could reproduce the full pattern of response time data and generate responses prior to cue encoding. The authors conclude by discussing directions for further model development.