Semantic Cognition ― A Parallel Distributed Processing Approach

This groundbreaking monograph offers a mechanistic theory of the representation anduse of semantic knowledge, integrating the strengths and overcoming many of the weaknesses ofhierarchical, categorization-based approaches, similarity-based approaches, and the approach oftencalled "theory theory." Building on earlier models by Geoffrey Hinton in the 1980s and DavidRumelhart in the early 1990s, the authors propose that performance in semantic tasks arises throughthe propagation of graded signals in a system of interconnected processing units. Therepresentations used in performing these tasks are patterns of activation across units, governed byweighted connections among them. Semantic knowledge is acquired through the gradual adjustment ofthe strengths of these connections in the course of day-to-day experience.The authors show how asimple computational model proposed by Rumelhart exhibits a progressive differentiation ofconceptual knowledge, paralleling aspects of cognitive development seen in the work of Frank Keiland Jean Mandler. The authors extend the model to address aspects of conceptual knowledgeacquisition in infancy, disintegration of conceptual knowledge in dementia, "basic-level" effectsand their interaction with expertise, and many findings introduced to support the idea that semanticcognition is guided by naive, domain-specific theories.

Timothy T. Rogers is a research scientist at the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, England.