Cognitive conflicts hurt memory

Research consistently shows that cognitive conflict impairs immediate task performance, but their long-term impact is not clear. The current study was designed to investigate the influence of several types of cognitive conflict on subsequent memory systematically. In a task-switching paradigm participants had to carry out two semantic classification tasks which involved the same set of response keys. In Experiment 1 the stimuli were univalent, in Experiment 2 and 3, the stimuli were bivalent (relevant for both tasks). This allowed us to investigate three conflict types: task switching, stimulus bivalency and response compatibility. After the encoding phase consisting of the task switching paradigm, participants completed a surprise recognition test, either immediately or after a one week interval. The immediate test revealed that subsequent memory was consistently lower for switch compared to repetition stimuli and this effect was enhanced with bivalent stimuli. In the delayed test, the advantage for repetition stimuli disappeared, but a response-compatibility effect emerged: compatible stimuli (stimuli requiring the same response keys for both tasks) were remembered better than incompatible stimuli (stimuli requiring different response keys for each task). Together, the results indicate that cognitive conflict as triggered by task switching, bivalent stimuli, and incompatible stimulus-response mappings can hurt subsequent memory. The specific effects, however, seem to depend on the specific type of conflict and the test delay.