Research Associate Professor
Main Office: IRC 1.408
Alternate Office: SEA 6.108
Alt. Phone: 512-232-5270
Imaging Research Center
3925B West Braker Lane
Austin ,TX 78759
Research SummaryMission: to develop new neuroimaging methods that permit precise quantitation of brain function and structure, with particular emphasis on the study of vision and visual cortex. The research falls into three areas: magnetic resonance imaging (MRI), hemodynamics, and vision science.
In the area of MRI, we are concentrating on techniques that better measure the laminar distribution of brain function in human cerebral cortex. These techniques include functional thickness, a method to quantify the width of the laminar profile hemodynamic activity, which may have clinical applications regarding neurodegenerative diseases. Other techniques include MRI approaches such as non-Cartesian sampling and reconstruction methods.
Our hemodynamics research has two directions. First, we are using high-resolution MRI to resolve differences in the hemodynamic time course observed in white matter, cortical gray matter, or vascular structures superficial to the pial surface. By using <1-mm voxels, we can also examine variations in the response as a function of depth in the gray matter. Second, we are developing models of oxygen transport and the BOLD response that make use of lumped, linear networks of blood flow. These models give an excellent match to measurements of extravascular oxygen concentration, and to the BOLD response.
Finally, we are working to apply these high-resolution MRI methods to understand mechanisms of perception in early visual cortex. We have particular interests in the laminar basis of visual attention, which boosts activity in all early visual cortical areas, including V1. We also have interests in the use of performance metrics to discern the links between hemodynamic activity, as measured using fMRI, and the computations necessary to solve visual discrimination tasks.