Electrocortical differentiation of evaluative and nonevaluative categorizations

The evaluative categorizations that underlie affective and attitudinal judgments have often been equated with non-evaluative categorizations despite the central importance of evaluative processes for survival. In the present experiment, a late positive potential (LPP) of the event-related brain potential elicited when participants evaluatively categorized food items as positive or nonpositive was compared with the LPP elicited when participants semantically (i.e., nonevaluatively) categorized food items as vegetable or nonvegetable. Results revealed that evaluative categorizations evoked an LPP that was relatively larger over the right than the left scalp regions compared with the LPP evoked by nonevaluative categorizations. This finding provides evidence regarding the differences in neural and cognitive processes involved in evaluative and nonevaluative categorizations.