Developmental Neuroscience Commons^™

Magnetic Resonance Imaging Of Brain Tissue Abnormalities: Transverse Relaxation Time In Autism And Tourette Syndrome And Development Of A Novel Whole-Brain Myelin Mapping Technique, Yann Gagnon

University of Western Ontario - Electronic Thesis and Dissertation Repository

The transverse relaxation time (T2) is a fundamental parameter of magnetic resonance imaging sensitive to tissue microstructure and water content, thus offering a non-invasive approach to evaluate abnormalities of brain tissue in-vivo. Prevailing hypotheses of two childhood psychiatric disorders were tested using quantitative T2 imaging and automated region of interest (ROI) analyses. In autism, the under-connectivity theory, which proposes aberrant connectivity within white matter (WM) was assessed, finding T2 to be eleveted in the frontal and parietal lobes, while dividing whole brain data into neurodevelopmentally relevant WM ROIs found increased T2 in bridging and radiate WM. In Tourette syndrome, tissue ...

Brain Function Differences In Language Processing In Children And Adults With Autism, Diane L. Williams, Vladimir L. Cherkassky, Robert A. Mason, Timothy A. Keller, Nancy J. Minshew, Marcel Adam Just

Marcel Adam Just

No abstract provided.

Adults’ And Infants’ Perception Of Pitch-Evoking Stimuli With No Resolvable Spectral Cues, Blake E. Butler

Open Access Dissertations and Theses

Pitch perception depends on two types of cues provided by acoustic stimuli: spectral cues arise from the tonotopic organization of the basilar membrane, while temporal cues are contained within the pattern of action potentials generated in auditory nerve fibers. Filtered iterated rippled noise (IRN) can be used to examine how adults and infants perceive stimuli without resolvable spectral cues. Chapter 2 uses event-related potentials (ERPs) to compare adult perception of IRN and complex harmonic stimuli. Functional imaging studies have revealed a common pitch centre along lateral Heschl’s gyrus, but lack the temporal resolution to index different stages of processing ...

Cortical Thickness In Major Depressive Disorder Across The Lifespan, Wanda Truong

Open Access Dissertations and Theses

This thesis presents research investigating structural neural correlates of major depressive disorder (MDD). Although there are clear clinical differences between early- and late-onset MDD, they are still subject to the same diagnostic criteria and treatment strategy. Whether these differences translate into differences in cortical structure was examined in this study. By directly comparing early-onset (EOD) and late-onset (LOD) patients, we test whether age-of-onset results in changes in the extent or spatial pattern of cortical thinning.

Chapter 1 provides a general background on the cerebral cortex, followed with a focus on cortical thickness. Chapter 2 presents a comprehensive review of the ...

Effect Of Nicotine On Body Composition, Laura O'Dell

Laura Elena O'Dell

No abstract provided.