Date of Award


Publication Type

Doctoral Thesis

Degree Name





Psychology, Clinical.


Rourke, Byron P.,




Autism is widely accepted to be a genetically based neurodevelopmental disorder. At present, however, there is no consistent evidence of a specific gene, neural pathway, or brain region abnormality to account for its expression. A variety of theoretical models have been proposed, with a particular focus on regions such as the cerebellum, hippocampus, and frontal cortex. In this study, specific consideration is given to a role for the thalamus in autism. Whereas the thalamus has traditionally been referred to as the sensory gateway to the cortex, a current perspective of this structure suggests that it is involved in multiple processes that permit the transmission, tuning, and integrated processing of information in the brain. With advances In neuroimaging technology, more detailed measurement of the volume of diverse regions of the brain has been permitted. In the present study, a volumetric analysis of the thalamus was conducted using MRI in 12 high-functioning individuals with autism and 12 matched controls. Differences were not revealed when unadjusted mean thalamic volume was considered. However, significant findings were obtained when total brain volume was taken into account. Specifically, there was a significant difference in mean thalamic volume between individuals with autism and normal controls within the "HIGH" total brain volume group. Furthermore, there was evidence to suggest that the relationship between thalamic volume and brain volume, as well as right and left side of thalamus, was significantly different in autistic subjects versus normal controls. The results of this study offer preliminary support for further study of this structure. The thalamus is not advanced as a primary causal mechanism in autism, but rather, as a structure that forms an integral part of a network of neural systems that is relevant to understanding this disorder.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .T73. Source: Dissertation Abstracts International, Volume: 61-09, Section: B, page: 5009. Adviser: Byron P. Rourke. Thesis (Ph.D.)--University of Windsor (Canada), 2000.