Semantic Feature Type Constrains the Organization and Computation of Concrete Conceptual Knowledge

• Main Author: Amsel, Benjamin David
• Other Authors: Cree, George
• Language: en_ca
• Published: 2011
• Subjects: conceptual knowledge; semantic memory; language comprehension; word recognition; mixed-effects; ERP; 0633
• Online Access: http://hdl.handle.net/1807/27571

This thesis addresses the computation and organization of conceptual knowledge. Specifically, it focuses on the recruitment of concrete knowledge during single word reading using behavioural and electrophysiological methodologies. Chapters 1 and 2 assess how number of visual semantic features listed by participants as being part of a given concept influence the speed of word meaning computation, and its neural underpinnings, providing evidence for modality-specific neural organization. Chapter 3 assesses the flexibility of knowledge activation as a function of specific task constraints, suggesting a multi-faceted approach to semantic richness is needed. Chapter 4 describes a novel application of recent statistical advances to the analysis of real-time electrophysiological data, and highlights some limitations of standard analytical approaches. Chapter 5 assesses the real-time influence of several types of knowledge on the neuroelectric activity underlying concrete word meaning computation. A timecourse of sensory-based knowledge type activation is outlined. Finally, Chapter 6 describes a novel approach whereby real-time electrophysiological brain activity is used to predict the speed of semantic decision making, providing further evidence of a highly flexible, but finely structured, human semantic memory system.