Cognitive processes involved in the representation of conceptual knowledge: Toward a unified theory

Categorization is a fundamental aspect of cognition and allows us to learn about the world. For example, we learn to categorize which plants are edible, which animals are predators, and who our friends are. Research on categorization has reached an impasse that has become familiar in a variety of other domains of psychology how to reconcile effects observed in patient populations and brain images with different effects observed in behavioural research. Studies involving brain imaging and amnesic patients indicate that categorization depends on the similarity of the test items to the prototype rather than recognition memory for the study items and this knowledge is predicated on an implicit system. By contrast computational modelling and purely behavioural techniques have emphasized the similarities between categorization and recognition. Memory-based models explain dissociations between categorization and recognition by positing a single process with different judgement heuristics. Although memory-based computational models can simulate the behavioural dissociations observed in amnesic patients they cannot account for the involvement of different brain regions observed via imaging techniques. The main aim of the proposed project is to determine if a common set of principles can unite these two strands of research.