Date of Award

Spring 2008

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering - (M.S.)

Department

Biomedical Engineering

First Advisor

Bharat Biswal

Second Advisor

Richard A. Foulds

Third Advisor

Tara L. Alvarez

Fourth Advisor

Atam P. Dhawan

Abstract

Functional magnetic resonance imaging (fMRI) studies dealing with Autistic children have primarily been concerned with cognitive facial recognition. Recent studies have demonstrated that Autistic children, when compared to healthy matched controls, exhibit higher neuronal activity when identifying patterns or objects, but lower levels of activity in regards to facial recognition.

The objective of this study was to examine both facial and object recognition and compare them to simple sensorimotor tasks. All subjects were administered 5 stimuli each lasting 320 seconds. Subjects were instructed to use a button press box to identify between a Person/Object and an Arrow/Object. They were then asked to complete three simple sensorimotor tasks of Mouth Open/Closed, Eyes Left/Right, and Eyes Open/Closed.

It was hypothesized that matched healthy controls would show a higher level of activation, specifically in the frontal gyrus. Attention was focused on the middle frontal gyms and the inferior frontal gyms, of both the left and right sides of the brain. Temporal correlations between these 4 regions-of-interest (ROIs) were examined for all 5 stimuli. A ttest was then performed across subjects to reveal differences in correlation coefficients between the 4 ROIs in relation to these two subject groups. The investigation demonstrated reduced overall activation, as well as reduced correlation coefficients among the 4 ROIs, in Autistics when compared to healthy matched controls. These findings suggest that Autistics may have compromised connectivity between these brain regions.

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