Effect of aging on choice-induced cognitive conflict.

When individuals are forced to choose between similarly preferable alternatives, a negatively arousing cognitive conflict occurs, and the preference attitudes toward the chosen and rejected alternatives diverge. This phenomenon, often referred to as "cognitive dissonance", is of interest in psychological and decision neuroscience research. The dorsal anterior cingulate cortex (dACC) is involved in representing the cognitive conflict induced by difficult-choice tasks. Previous studies have shown age-related decline of the dACC function. However, whether the heightened activity of the dACC regarding cognitive conflict, and choice-induced preference change that behaviorally occur in young subjects also occur in the elderly is unclear. Furthermore, recent studies have noted substantial methodological flaw with the free-choice paradigm that often used in studies focusing on cognitive dissonance. Here, we used functional magnetic resonance imaging (fMRI) and a modified free-choice paradigm to formally test the effect of aging on choice-induced cognitive conflict. In the young participants, behavioral data confirmed the existence of cognitive conflict and preference change for the alternatives that they rejected in the difficult-choice trials. The imaging data revealed that the right dACC displayed an interaction effect associated with cognitive conflict. In contrast, we did not observe such effects in the elderly participants. These suggest a possibility that elderly people likely feel less cognitive dissonance.