If Attitudes Affect How Stimuli Are Processed, Should They Not Affect the Event-Related Brain Potential?

Abstract

In Experiment 1, subjects completed an attitude survey to identify items toward which they held positive and negative attitudes. Subsequently, subjects were instructed to count the number of positive (or negative) stimuli in a series. Each series contained six attitude stimuli from a given semantic category (e.g., fruits), and the structure of the series was varied so that positive and negative stimuli, as indexed by subjects' idiosyncratic attitudes, were evaluatively consistent or inconsistent within the series. In Experiment 2, subjects were exposed to personality traits that were positive or negative in series of six. Again, the structure of the series was varied so that positive and negative traits were evaluatively consistent or inconsistent within the series. Results of Experiments 1 and 2 indicated that although the event-related brain potential did not differ as a function of stimulus valence per se, evaluatively inconsistent, in contrast to consistent, stimuli evoked a larger amplitude late P300-like positive component that was maximal over the centroparietal region.