Remembering Vs. Knowing - the Self and Comprehension in Autism Spectrum Disorder
Author: Sabine Vera Huemer
Publisher:
Published: 2014
Total Pages: 123
ISBN-13: 9781321020946
DOWNLOAD EBOOKThis three-part thesis investigates the language processing of autism spectrum disorder (ASD), with special attention to self-reference. The first examined reading skills in 384 children and adolescents with ASD as compared to 100 participants with dyslexia. A pattern of relatively intact decoding skills paired with low comprehension was found in ASD subjects, while dyslexic subjects showed the opposite pattern. The second paper used magnetic resonance imaging (MRI) investigation, voxel-based morphometry (VBM), tensor based morphometry (TBM) and diffusion tensor imaging (DTI) to analyze white and grey matter concentrations (WMC/GMC), microstructure and shape differences in 20 adolescents with ASD as compared to 10 neurotypical controls. The ASD group exhibited regions of WMC and GMC abnormalities and shape differences in various key loci for social cognition and self-reference; group analysis based on receptive verbal skill revealed analogous abnormalities in major neural networks, suggesting an anatomical basis of high vs. low functioning subtypes within ASD. The third paper compared brain activation in a subgroup of ASD subjects and neurotypical controls who passively heard their own names, other (familiar) people's names, objects of high interest, and numbers. The self-referent stimuli activated key brain regions in controls that are linked to self-reference and embedded in long-term memory in a more posterior neural network. In ASD subjects these stimuli activated anterior brain regions associated with short-term episodic memory. The possibility of anatomical subtypes was again implied by analysis based on receptive verbal skill. These three studies suggest that reduced self-reference aligns with comprehension weaknesses in autism and that self-referent information is not implicitly "known" but rather acquired and "remembered" like factual information, especially in `lower functioning' ASD subjects characterized by lower verbal ability.