Event-Related Potential Brain Correlates of Episodic and Semantic Memory in Adults with Autism Spectrum Disorder
type: CreativeWork
description: The aim of this thesis was to refine current models of memory in Autism Spectrum Disorder (ASD) and elucidate similarities and differences between memory in ASD and that of Typically Developing (TD) individuals. This thesis built upon recently established behavioural patterns of preserved semantic and diminished episodic memory in ASD, by linking these with established patterns of electrophysiological activity in different cortical regions of the brain in TD individuals. Event-Related Potential (ERP) Old-New effects (enhanced positivity in the brain for correctly recognised Old stimuli compared to correctly rejected New stimuli) were recorded for episodic and semantic memory judgments (the parietal Old-New effect 400-800 ms, and the mid-frontal Old-New effect 300-500 ms respectively) in ASD, and were compared to TD individuals in terms of (1) temporal and (2) topographical similarities and differences. A series of five experimental studies were conducted using nameable line drawings, non-nameable kaleidoscope images and words as stimuli. A combination of two experimental paradigms were used; the Remember/Know paradigm and the Inclusion/Exclusion paradigm. The current thesis demonstrates that recognition memory Old-New effects are attenuated in ASD for word stimuli and nameable line drawings, but that the topography remains comparable between groups. The current findings suggest that although episodic memory is quantitatively diminished in ASD during behavioural tests, residual episodic memory judgements are phenomenologically similar to TD individuals. Despite demonstrating quantitatively preserved semantic memory, different patterns of neurophysiology are observed for these judgements in ASD, suggesting that different processes are engaged in this group. Finally, although individuals with ASD demonstrated diminished Old-New effects for nameable line drawing and word stimuli compared to TD individuals, enhanced Old-New effects were observed for non-nameable and nove…
abstract: The aim of this thesis was to refine current models of memory in Autism Spectrum Disorder (ASD) and elucidate similarities and differences between memory in ASD and that of Typically Developing (TD) individuals. This thesis built upon recently established behavioural patterns of preserved semantic and diminished episodic memory in ASD, by linking these with established patterns of electrophysiological activity in different cortical regions of the brain in TD individuals. Event-Related Potential (ERP) Old-New effects (enhanced positivity in the brain for correctly recognised Old stimuli compared to correctly rejected New stimuli) were recorded for episodic and semantic memory judgments (the parietal Old-New effect 400-800 ms, and the mid-frontal Old-New effect 300-500 ms respectively) in ASD, and were compared to TD individuals in terms of (1) temporal and (2) topographical similarities and differences. A series of five experimental studies were conducted using nameable line drawings, non-nameable kaleidoscope images and words as stimuli. A combination of two experimental paradigms were used; the Remember/Know paradigm and the Inclusion/Exclusion paradigm. The current thesis demonstrates that recognition memory Old-New effects are attenuated in ASD for word stimuli and nameable line drawings, but that the topography remains comparable between groups. The current findings suggest that although episodic memory is quantitatively diminished in ASD during behavioural tests, residual episodic memory judgements are phenomenologically similar to TD individuals. Despite demonstrating quantitatively preserved semantic memory, different patterns of neurophysiology are observed for these judgements in ASD, suggesting that different processes are engaged in this group. Finally, although individuals with ASD demonstrated diminished Old-New effects for nameable line drawing and word stimuli compared to TD individuals, enhanced Old-New effects were observed for non-nameable and nove…
author: Massand, Esha
keywords: BF Psychology
date published: 2011-10
date modified: 2026-07-24T01:38:52Z
provider: City University of London
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: City University London