Event-related Potential Parameters Related To Premise And Conclusion Typicality Effects During Category-based Induction

Inductive reasoning is an advanced form of thinking,which refers to the process of making inferences from the special object or event to the general object or event.Categorizing information about the world plays a key role in Inductive reasoning.The inductive reasoning that based on categorization is called category-based induction.Typicality is one of the most robust properties of a category,reflecting its graded structure.In a concept,not all members are equal.Some items are judged as typical members,whereas others are judged as atypical ones.Typical members of a concept receive more preferential processing than do atypical members of the same concept.This phenomenon is referred to as the typicality effect.Three experimental researches were performed to explore the event-related potential(ERP)responses to conclusion and premise typicality effects during category-based induction.In the three studies,a single premise category-based property induction task was used.In study 1,the event-related potential(ERP)responses to conclusion typicality effects on conclusion category stage and conclusion property stage during category-based induction were measured separately.Behavioral results showed shorter reaction times and higher “yes” response rates of typical conclusions than that of atypical conclusions.With regard to ERPs,on the conclusion category stage,typical conclusions elicited larger P2 and smaller N400 than did atypical conclusions.On the conclusion property stage,when the conclusion properties were consistent to the premise properties,typical conclusions elicited larger P3 b than did atypical conclusions.On the basis of study 1,study 2 explored the event-related potential responses to premise typicality effects on conclusion category stage and conclusion property stage during category-based induction in which the conclusions were basic-level categories.The results were consistent with the study 1.Behavioral results revealed that thereaction times of conclusions inferred from typical premises were shorter than that of the conclusions inferred from atypical premises.And the “yes” response rates of conclusions inferred from typical premises were higher than that of the conclusions inferred from atypical premises.What’s more,the ERPs results showed that conclusions inferred from typical premises elicited larger P2 and smaller N400 than did conclusions inferred from atypical premises on the conclusion category stage,and on the conclusion property stage,when the conclusion properties were consistent to the premise properties,conclusions inferred from typical premises elicited larger P3 b than did conclusions inferred from atypical premises.On the basis of study 1 and 2,study 3 explored the event-related potential responses to premise typicality effects on conclusion category stage and conclusion property stage during category-based induction in which the conclusions were super-ordinate categories related to the premise.Behavioral results showed shorter reaction times of conclusions inferred from typical premises were shorter than that of the conclusions inferred from atypical premises.And the “yes” response rates of conclusions inferred from typical premises were higher than that of the conclusions inferred from atypical premises.Moreover,the ERPs results showed that typical premises elicited smaller N400 than did atypical premises on the conclusion category stage,and on the conclusion property stage,when the conclusion properties were consistent to the premise properties,conclusions inferred from typical premises elicited larger P3 b than did conclusions inferred from atypical premises.Results of the 3 studies consistently showed that:(1)on the conclusion category stage,atypical conditions elicited larger N400 than did typical conditions,which suggested the enhanced cognitive effort on the semantic integration in atypical conditions than in typical conditions;(2)on the conclusion property stage,when the conclusion properties were consistent to the premise properties,typical conditions elicited larger P3 b than did atypical conditions,reflecting the higher degree of expect satisfaction during reasoning.Therefore,during acceptable category-based induction,N400 indexed the typicality effects on the conclusion category stage,and P3 b indexed the typicality effects on the conclusion property stage respectively.