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Full-Text Articles in Biomedical Engineering and Bioengineering

Supraspinal Control Of Unilateral Locomotor Performance: An Fmri Study Using A Custom Pedaling Device, Brett Arand Oct 2013

Supraspinal Control Of Unilateral Locomotor Performance: An Fmri Study Using A Custom Pedaling Device, Brett Arand

Master's Theses (2009 -)

This study aimed to develop a novel unilateral pedaling device, validate its function, and use it in an fMRI study of bilateral vs. unilateral locomotor control. The new device is MRI compatible and allows for conventional coupled bilateral pedaling, along with decoupled unilateral pedaling. It was designed with an assistance mechanism to simulate the presence of the non-contributing leg while pedaling unilaterally. During coupled bilateral pedaling, the two legs work in unison: while one leg is extending in the downstroke, it provides support to lift the other leg back up as it is flexing in the upstroke. The device uses ...


Changes In Hemodynamic Responses In Chronic Stroke Survivors Do Not Affect Fmri Signal Detection In A Block Experimental Design, Nutta-On Promjunyakul, Brian D. Schmit, Sheila Schindler-Ivens Sep 2013

Changes In Hemodynamic Responses In Chronic Stroke Survivors Do Not Affect Fmri Signal Detection In A Block Experimental Design, Nutta-On Promjunyakul, Brian D. Schmit, Sheila Schindler-Ivens

Physical Therapy Faculty Research and Publications

The use of canonical functions to model BOLD-fMRI data in people post-stroke may lead to inaccurate descriptions of task-related brain activity. The purpose of this study was to determine whether the spatiotemporal profile of hemodynamic responses (HDRs) obtained from stroke survivors during an event-related experiment could be used to develop individualized HDR functions that would enhance BOLD-fMRI signal detection in block experiments. Our long term goal was to use this information to develop individualized HDR functions for stroke survivors that could be used to analyze brain activity associated with locomotor-like movements. We also aimed to examine the reproducibility of HDRs ...


Detecting Activity-Evoked Ph Changes In Human Brain, Hye Young Heo Jul 2013

Detecting Activity-Evoked Ph Changes In Human Brain, Hye Young Heo

Theses and Dissertations

Localized pH changes have been suggested to occur in the brain during normal function. However, a lack of methods for non-invasively measuring pH with high spatial and temporal resolution limits current knowledge of brain pH dynamics. Here I report that a magnetic resonance imaging (MRI) strategy named T1 relaxation in the rotating frame (T) is sufficiently sensitive to detect widespread pH changes in the mouse and human brain evoked by systemically manipulating carbon dioxide (CO2) or bicarbonate (HCO3). Moreover, T detected changes suggesting a localized acidosis in the human visual cortex induced by a flashing ...


The Effects Of Separating Visual And Motor Workspaces On The Generalization Of Visuomotor Adaptation Across Movement Conditions, Yuming Lei Jul 2013

The Effects Of Separating Visual And Motor Workspaces On The Generalization Of Visuomotor Adaptation Across Movement Conditions, Yuming Lei

Master's Theses (2009 -)

Separating visual and proprioceptive information in terms of workspace locations during reaching movement has been shown to disturb transfer of visuomotor adaptation across the arms. Here, we investigated whether separating visual and motor workspaces would also disturb generalization of visuomotor adaptation across movement conditions within the same arm. In our behavioral study, subjects were divided into four experimental groups (plus three control groups). The first two groups adapted to a visual rotation under a "dissociation" condition in which the targets for reaching movement were presented in midline while their arm performed reaching movement laterally. Following that, they were tested in ...


Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe Jan 2013

Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe

Biomedical Engineering Faculty Research and Publications

fMRI is becoming an important clinical tool for planning and guidance of surgery to treat brain tumors, arteriovenous malformations, and epileptic foci. For visual cortex mapping, the most popular paradigm by far is temporal phase mapping, although random multifocal stimulation paradigms have drawn increased attention due to their ability to identify complex response fields and their random properties. In this study we directly compared temporal phase and multifocal vision mapping paradigms with respect to clinically relevant factors including: time efficiency, mapping completeness, and the effects of noise. Randomized, multifocal mapping accurately decomposed the response of single voxels to multiple stimulus ...