I started graduate school in the fall of 2007 and my current research pursuits involve examining top down influences of the human Frontal Eye Fields on parietal and occipital visual cortex networks. A substantial amount of research from the last few years has demonstrated that the FEF has a substantial role in attentional processes, specifically in visuospatial selection. I'm currently investigating the visuospatial selection and attention processes for both overt (saccades) and covert shifts of attention using psychophysics, transcranial magnetic stimulation, and electroencephalography.
EEG is a particularly advantageous electrophysiology technique because of it's high temporal resolution. The rapidly changing TMS magnetic field strength maximizes at .2 milliseconds, and returns to zero by 1 ms. In order to measure the rapid brain changes that accompany such a brief stimulus, a recording system capable of sampling at 512-1024Hz is needed to prevent aliasing and other undesirable sampling errors. The advanced BioSemi EEG system here in the Klein lab makes for an ideal opportunity to study the specific effects that TMS has on neural networks involved in visuospatial selection and attention.
The TMS technique is noninvasive and the effects are very short term with no permanent damage or lasting changes in cortical functioning. The TMS pulse extends about 2.5-3cm deep from the surface of the scalp, so it is particularly useful for studying cortical processes on the surface of the neocortex. The human Frontal Eye Field is located at the intersection of the superior frontal sulcus and the pre-central sulcus, allowing for easy access with TMS. I presented an abstract and poster at VSS 2010 on the effects of single pulse FEF TMS on saccade onset, and on bilaterality of the right hemisphere. My results show that the right FEF does have bilateral involvement in saccade production, manifest by delayed saccade onset to both left and right visual fields. It is suspected that the left FEF is only unilateral based on extensive literature in imaging and electrophysiology, but for the moment I have not yet investigated this topic with TMS.
Additionally, I am currently running psychophysics experiments on the transient capture of visuospatial attention to determine whether or not non-predictive cueing can locally enhance attentional allocation and thereby improve perceptual sensitivity under conditions of divided attention. This is a highly debated topic in Cognitive Psychology and Neuroscience, and the approach I am taking is unique in that the experiment task is not one of perceptual enhancement or reaction time, but instead is a task which maximizes the utilization of attentional resources up to threshold. The experiment is not one of perceptual judgement, but instead one of attentional capacity and the ability of the subject to split covert attentional resources among 7 targets near-simultaneously. This investigation also has a perceptual learning component since subjects show improved performance and higher thresholds within the first hour of training.
I'm also very interested in philosophical topics surrounding Neuroscience, such as the Philosophy of Mind and Philosophy of Science. I'm actively involved in the Townsend Center Working Group in the Philosophy of Mind, an organization of philosophers, neuroscientists, and psychologists who gather and discuss leading scientific and philosophical publications and research in the interest of increasing interaction between scientists and philosophers.
Some of my non-academic interests include motorcycles, auto mechanics, aviation, paragliding, kayaking, biking, guitar, piano, strength training, welding, and swimming.
2006 - B.S. in Applied Psychology (minor in Philosophy), Arizona State University
2007 - 2012 Ph.D. (expected), Vision Science, UC Berkeley, Berkeley, CA