Event-related potential parameters related to typicality effects during category-based induction

Abstract

Previous event-related potential (ERP) studies investigating the typicality effects during category-based reasoning were conducted during the deduction and induction phases by comparing typical and atypical conclusion categories, without property inference processes. In the present study, the ERP responses to both conclusion typicality effects (strengthening of the inference from “durian has the novel property X1” to “apple has the novel property X1” [a typical conclusion]was stronger than the inference from “durian has the novel property X1” to “Chinese date has the novel property X1 [an atypical conclusion], experiment 1) and premise typicality effects (strengthening of the inference from “apple has the novel property X1”[a typical premise]to “durian has the novel property X1” was stronger than the inference from “Chinese date has the novel property X1”[an atypical premise] to “durian has the novel property X1”, experiment 2) during category-based induction were measured by separately presenting the conclusion categories and conclusion properties. The results of both the experiments showed that, during the conclusion-category stage, typical conditions elicited larger P2 responses than atypical conditions, suggesting increased semantic feature activity in typical conditions. Additionally, atypical conditions elicited larger N400 responses than typical conditions, suggesting the increased cognitive effort related to semantic integration in atypical conditions than in typical conditions. During the conclusion-property stage, when participants accepted the inferences, both the experiments showed that typical conditions elicited larger P3b responses than atypical conditions, reflecting the higher degree of expected satisfaction during reasoning. Therefore, when the inferences were positive during category-based induction, N400 responses indexed the typicality effects during the conclusion-category stage, whereas P3b responses indexed the typicality effects during the conclusion-property stage.