The Role Of Thematic And Taxonomic Knowledge In Fear Generalization

Overgeneralization of fear is a core feature of anxiety,a stress-related illness,and a manifestation of learning and memory disorders.The generalization of fear in daily life is very extensive,involving people,things,scenes in space and time.The theory and discovery of fear generalization based on the similarity of perception and concept cannot fully explain the phenomenon of fear generalization in daily life.Concept knowledges are organized in two ways: taxonomic relation based on similarity and thematic relation based on spatio-temporal co-occurrence.How these two relationships affect fear generalization simultaneously,what’s the electrophysiological response of fear generalization,whether fear generalization can be performed on unconscious level,and how childhood trauma experiences effect the response of fear generalization are still lack of relevant evidence.To solve these problems,this study combined with behavior,ERP,and SCR technology,using classical fear conditioning paradigm,respectively from the concept relations processing,processing two aspects and the level of consciousness,system,and studied the normal childhood trauma experiences the fear of individual behavior and physiological characteristics of generalization process and the corresponding electrical activity time,provided new evidence for fear generalization model.The first study explored the conceptually based fear generalization and its electrophysiological mechanism in 40 healthy adults.The second study investigated the generalization of fear based on conceptual relationships and its electrophysiological mechanism in 25 healthy adults at conscious and unconscious levels.Study 3 explored the physiological and behavioral mechanisms of fear generalization at different levels of consciousness among adults with different levels of childhood trauma(21 with high childhood trauma and 26 with low childhood trauma).Research one finds that human fear can be generalized not only in classification relationships,but also in thematic relationships.In ERP,the result of P2 time window represents the conceptual relationship,which promotes fear generalization by improving attention,while the result of P6 time window indicates that fear generalization will in turn affect the semantic processing of concepts.The α-ERD response in video results may predict the emotional effects of fear generalization.The second study found that people’s fear can be generalized on the unconscious level,and the generalization of the unconscious level is broader than the conscious conditions.The generalization of conscious and unconscious fear has different processing in the course of time.In the process of unconscious fear generalization,individuals may experience the cognitive processes of early attention processing(N1),stimulus evaluation(P300),exclusion and discrimination(LPC).The third study found that the fear learning and generalization effects of childhood trauma on individuals can last into adulthood.Individuals with high childhood trauma showed high physiological arousal to cs-c in the stage of fear learning and high physiological arousal in the stage of generalization.The above results show that conceptual relationship plays an important role in promoting the generalization of fear,and concept-based fear generalization has different neural markers at different levels of consciousness.Childhood trauma will aggravate the generalization of fear.This study provides a new perspective for the fear generalization theory,with a view to providing certain reference for the treatment and prevention of anxiety,stress and depression-related diseases.