The Relationship Between Extinction Learning Processes and Callous Unemotional Traits

Abstract

Callous Unemotional (CU) traits are an informative clinical construct, identifying individuals at risk of conduct disorder and treatment resistance. This thesis examines associative processes that may underlie this resistance. Specifically, extinction learning processes, which allow individuals to maintain expectations that match the outcomes of their behaviour. It is often assumed that there is an established link between CU traits and deficient associative learning of this kind. However, a systematic review of the current literature, described in this thesis, reveals that the evidence for this relationship is not consistent. This finding indicated the need for a study of this correlation using a well powered experimental methodology. As a result, six studies were carried out to develop a computer-based task able to measure extinction learning in large samples from the general population, with CU traits assessed using the Inventory of Callous Unemotional Traits (ICU). Findings from this series included repeated observations of CU trait associated extinction deficits. They also provided unique data on whether CU traits affect the relapse of extinguished behaviour. Furthermore, an unanticipated effect of cultural factors was observed. In consideration of these findings, observed parameters were utilised in the design of a large-scale confirmatory study with over 700 participants. This study also investigated the role of cultural variables in the structure and external validity of the ICU, as well as its association with extinction learning. This thesis therefore provides useful data on the relationship between CU traits and extinction learning, as well as on the cross- cultural validity of the ICU, representing a significant contribution to our understanding of the aetiology and phenotypic characteristics of CU traits.