Bioelectrical Echoes From Evaluative Categorization: II. A Late Positive Brain Potential That Varies as a Function of Attitude Registration Rather Than Attitude Report

We report evidence of both correspondence and independence between participants' attitude report and a late positive potential (LPP) of the event-related potential. Attitude reports and LPPs to positive, neutral, and negative stimuli that were preceded by positive stimuli were recorded while participants either reported accurately their attitudes or misreported neutral or negative attitudes. Evaluatively inconsistent, in contrast to consistent, stimuli evoked a larger LPP regardless of whether participants reported accurately or misreported their attitudes. These results were replicated in a second study in which attitude reports and LPPs to negative, neutral, and positive stimuli that were preceded by negative stimuli were recorded. Findings suggest that the LPP evoked during evaluative judgments reflects attitude categorization rather than attitude report processes and can potentially assess attitudes that people are unwilling to report.