Browsing by Subject "cortex"

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    Capturing the Perceived Phantom Limb through Virtual Reality
    (Office of the Vice Chancellor for Research, 2015-04-17) Lau, Jonathan; Huynh, Denver; Albertson, Steven; Beem, James; Qian, Enlin
    Phantom limb is the sensation amputees may feel where the missing limb (occasionally an organ) is still attached to the body and is still moving as it would if it were there. Between 50-80% amputees report neuropathic pain, also known as phantom limb pain (PLP). Recent studies suggest that providing sensory input to the stump or amputation area may modulate how PLP can be related to neuroplastic changes in the cortex. However, there is still little understanding of why PLP occurs and there are no fully effective, long-term treatments available. Part of the problem is the difficulty for amputees to describe the sensations of their phantom limbs due to the lack of a physical limb as well as phantom limbs that are in positions that are impossible to attain. This project aims to develop an effective 3D tool with the Maya 3D animation software and the Unity game engine. The tool will then be used for those with phantom limb syndrome to communicate the sensations accurately and easily through various hand positions using a model arm with a user friendly interface. The 3D model arm will be able to mimic the phantom sensation, being able to go beyond normal joint extensions of a regular arm. This way we can have a true 3D visual of how the amputee with phantom limb feels if it is abnormal. Testing the effectiveness of the tool will involve a pilot study with able-bodied volunteers. The non-dominant limb of the volunteers will be hidden behind a blind. After putting their limb in a random position, they will attempt to capture the limb on the 3D model. The actual position and captured position will be compared to determine the reproducibility and accuracy of the virtual limb. By taking advantage of computer graphics, virtual reality and computerized image capture technologies we are hoping to achieve a far less challenging way to quickly and accurately capture the position and striking feelings of the phantom limb sensation.
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    Comparison of rhyming and word generation with FMRI
    (Wiley Open Access, 2000-06-06) Lurito, Joseph T.; Kareken, David A.; Lowe, Mark J.; Chen, Shen Hsing A.; Mathews, Vincent P.; Neurology, School of Medicine
    Functional magnetic resonance imaging (FMRI) has been successfully used to non‐invasively map language function, but has several disadvantages. These include severe motion sensitivity, which limits overt verbal responses in behavioral paradigms, such as word generation. The lack of overt responses prevents behavioral validation, making data interpretation difficult. Our objective was to compare the FMRI activation patterns of a novel silent rhyme determination task requiring a non‐verbal response, to covert word generation from visually presented letters. Five strongly right‐handed subjects performed both tasks during multi‐slice coronal echo‐planar T2*–weighted FMRI. Single subject activation maps were generated for each task by correlation analysis of single pixel time series to a boxcar reference function. These maps for the two tasks were separately interpolated to 2563, transformed into Talairach space, summed, and thresholded at t>6. Combined activation maps from both tasks showed similar robust perisylvian language area activation, including inferior frontal gyrus, posterior superior temporal lobe, and fusiform gyrus. Subjects performed well on the rhyming task, which activated left hemisphere cortical regions more selectively than the word generation task. The rhyming task showed less activation than the word generation task in areas typically not considered specifically related to language function, such as the dorsolateral prefrontal cortex and anterior cingulate. The rhyming task is a useful tool for brain mapping and clinical applications, potentially more specific to cortical language areas than verbal fluency.