My joint appointment in the departments of Psychology and Radiology reflects the division of my research interests. Employing a combination of visual psychophysics and fMRI, I want to determine how detection of local image features interacts with scene perception. How are local features in an image selected and grouped to construct a mental representation of a scene or object? To what extent do internal templates determine feature selection and shape perception?
I also spend time investigating the linkage between what BOLD fMRI measures (changes in blood oxygenation) and what we want to know (the underlying neural activity). Is it the input or the output of a visual area that drives the blood flow response? Are excitation and inhibition always balanced, or can inhibition drive the BOLD response as well as excitation? How do spatial characteristics of vascular regulation distort our view of spatially distributed neural activity?
More details about current research in my lab can be found at http://vision.psych.umn.edu/~caolman.
Olman, C. A., Inati, S., & Heeger, D. H. (2007). The effect of large veins on spatial localization with GE BOLD at 3 T: displacement, not blurring. NeuroImage, 34, 1126-1135.
Olman, C. A., & Kersten, D. J. (2004). Classification objects, ideal observers and generative models. Cognitive Science, 28, 227-239.
Olman, C. A., Schrater, P., Ugurbil, K., & Kersten, D. (2004). BOLD fMRI and psychophysical measurements of contrast response to broadband images. Vision Research, 44, 669-683.
