An ERP Study of the Effects of Category Knowledge and Contextual Knowledge Using a Cue-Target Matching Paradigm.

Abstract

Object categorization depends not only on the current visual input but also on prior knowledge. However, whether different types of prior knowledge influence object categorization with the same temporal profile remains unclear. In this study, we combined a cue-target matching paradigm with event-related potentials (ERPs) to compare the effects of category knowledge and contextual knowledge on object categorization. Category knowledge was manipulated at the superordinate, intermediate, and basic levels, whereas contextual knowledge was based on typical color and scene information. The behavioral results showed that cue-target congruency affected task performance, with different patterns observed across cue conditions. The ERP results further revealed that prior knowledge influenced multiple stages of processing, but the temporal pattern varied across conditions. Category knowledge showed level-dependent effects across intermediate, conflict, and later processing stages, whereas contextual knowledge was associated mainly with P2 and N400 modulation. These findings suggest that different types of prior knowledge contribute to object categorization with different temporal dynamics and that these differences may be related to how the relevant information is structured and used during cue-target matching.