Poster E136, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
An event-related potential and time-frequency study of cognitive dissonance-elicited attitude change
Adam Burnett1, Mario Liotti1; 1Simon Fraser University
The psychological discomfort experienced during cognitive dissonance often motivates individuals to engage in dissonance-reducing attitude change. Despite the influence that cognitive dissonance theory has had in psychology over the last sixty years, the neural correlates of cognitive dissonance have only recently been investigated. We used electroencephalography (EEG) to explore cognitive dissonance-elicited attitude change in 37 undergraduate participants while they engaged in a free-choice task. Participants rated a number of food items on desirability both prior to and after choosing between either similarly-rated (dissonant) or disparately-rated (consonant) item pairs. Event-related potentials (ERPs) time-locked to stimulus onset revealed that re-evaluation of dissonant choice items relative to consonant choice items gave rise to more negative voltage amplitudes over fronto-parietal scalp between 550-650ms, and over left lateral anterior scalp between 375-500ms during trials containing dissonance-reducing attitude change relative to trials without dissonance-reducing attitude change. Left lateral anterior scalp voltage amplitude was also found to be negatively correlated with the magnitude of resulting attitude change. At times and scalp locations corresponding to the ERP effects, a time-frequency analysis revealed greater low alpha power (9-11 Hz) during attitude change-absent trials relative to attitude change-present trials, as well as greater theta frequency power (4-8 Hz) for attitude change-present trials relative to attitude change-absent trials. These finding are consistent with a model of cognitive dissonance in which cortical projections of ventral striatal activity reflect reward signal changes, and where left prefrontal cortex is recruited for down-regulation of negative emotional arousal produced by cognitive dissonance.
Topic Area: THINKING: Decision making