Task Switching and Visual Search: Evidence for a Tradeoff Between Congruent and Incongruent Target Responses

Abstract

In task switching studies, mapping different responses to the same physical keys creates two response categories: congruent and incongruent. Congruent and incongruent responses are distinguished by whether or not a key press is the same between different task instructions. Task switching studies often report that incongruent responses have higher error rates and RTs than congruent responses. In this study, we investigate this congruency effect by asking: Does the presence of incongruent stimuli detract from performance on congruent stimuli? If true, participants may perform worse on congruent stimuli as more incongruent stimuli are added. To test this hypothesis, we created a visual search and task switching paradigm where participants search for targets while the congruence of a target changes. Results show a tradeoff in accuracy between incongruent and congruent targets—when incongruent stimuli are added, participants are worse at finding congruent stimuli, even though congruent stimuli are targets throughout the task.