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Movie-Driven Fmri Reveals Network Asynchrony And Connectivity Alterations In Temporal Lobe Epilepsy, Alenka Bullen

Electronic Thesis and Dissertation Repository

Mesial temporal lobe epilepsy (TLE) is the most common form of focal epilepsy and is often resistant to medication. Recent studies have noted brain-wide disruptions to several neural networks in so-called “focal” epilepsy, notably TLE, leading to it being recognized as a network disease. We aimed to assess the integrity of functional networks while they were simultaneously activated in an ecologically valid manner, using an actively engaging, richly stimulating audio-visual film clip. This stimulus elicits widespread, dynamic patterns of time-locked brain activity, measurable using functional magnetic resonance imaging. Thirteen persons with drug-resistant TLE (persons with epilepsy; PWE) and 10 demographically …

Neurocircuits Of Posttraumatic Stress Disorder And Its Dissociative Subtype, Andrew A. Nicholson

Electronic Thesis and Dissertation Repository

The amygdala and insula are highly implicated in the pathophysiology of posttraumatic stress disorder (PTSD), where both have been shown to be hyper/hypoactive in PTSD and dissociative subtype (PTSD+DS) PTSD patients, respectively, during symptom provocation. However, the functional connectivity of individual amygdala and insula subregions have not previously been compared in PTSD, PTSD+DS and healthy controls. In two separate studies, we examined amygdala complex (chapter 2) and insula subregion (chapter 3) functional connectivity patterns using resting-state fMRI. Patients with PTSD and PTSD+DS were found to display unique amygdala complex functional connectivity patterns to prefrontal cortex (PFC) regions involved in emotion …

Interactive Visualization Of Multimodal Brain Connectivity: Applications In Clinical And Cognitive Neuroscience, Saeed Mahdizadeh Bakhshmand

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) has become a readily available prognostic and diagnostic method, providing invaluable information for the clinical treatment of neurological diseases. Multimodal neuroimaging allows integration of complementary data from various aspects such as functional and anatomical properties; thus, it has the potential to overcome the limitations of each individual modality. Specifically, functional and diffusion MRI are two non-invasive neuroimaging techniques customized to capture brain activity and microstructural properties, respectively. Data from these two modalities is inherently complex, and interactive visualization can assist with data comprehension.

The current thesis presents the design, development, and validation of visualization and computation …

A Naturalistic Paradigm To Probe Conscious Information Processing During Sleep, Max M. Silverbrook

Electronic Thesis and Dissertation Repository

Sleep was long considered a passive mental state. The extent to which external information is integrated in, and consciously processed during sleep remains unknown. Here, simultaneous electroencephalographic (EEG) and functional magnetic resonance imaging (fMRI) data were collected from sleeping participants. First, the stimulus elicited significantly correlated fMRI activity in the auditory and fronto-parietal networks of awake participants. Behavioural testing found individuals to perceive the story’s suspense similarly. Then neural activity related to high-level processing of the story was investigated in 5 individuals who slept through it. Fronto-parietal activity in 1 individual in rapid eye movement (REM) sleep followed that of …