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Gregory McCarthy  Professor (Ph.D., 1980, University of Illinois at Urbana-Champaign) Research conducted in my laboratory is concerned with the functional anatomy of the human brain. Our methods include functional magnetic resonance imaging, intracranial human electrophysiology, direct cortical stimulation, and scalp-recorded event-related potentials. There are two themes of investigation. The first concerns the processing of complex visual stimuli, such as faces, objects, and letterstrings. Our research has identified discrete regions of the ventral occipitotemporal brain in the perception of faces and of letterstrings. We are now investigating whether these areas are influenced by attentional, semantic, and experiential factors and, if so, whether these influences represent top-down processes. Our work in face perception has recently expanded to investigate lateral temporal lobe regions that appear involved in processing dynamic aspects of visual stimuli, such as the perception of shifting gaze within an otherwise static face. In particular, we are interested in whether this lateral temporal region contributes to processing of complex biological cues that form a substrate for social perception. A second research theme has investigated the function of prefrontal cortex, particularly in the development of predictions or expectations, and in the processing of novel stimuli. In recent years, we have integrated the two research themes, by investigating differential response of prefrontal cortex and extrastriate visual cortex in the processing of complex stimuli that subjects must remember, or must discriminate among. In addition, my laboratory has maintained an active interest in the physiological relationship between event-related potentials measured with electrophysiological methods and the hemodynamic response measured with imaging methods. We have also recently published several papers that have investigated statistical properties of the hemodynamic response that have important consequences for event-related fMRI designs. Sample Publications Yamasaki,H. LaBar, K.S. and McCarthy, G. Dissociable Prefrontal Brain Systems for Attention and Emotion Proceedings of the National Academy of Sciences, 99: 11447-11451, 2002. Huettel, S.A., McKeown, M.J., Song, A.W., Hart, S., Spencer, D.D., Allison, T., and McCarthy, G. Linking hemodynamic and electrophysiological measures of brain activity: Evidence from functional MRI and intracranial field potentials. Cerebral Cortex, 14:165-173, 2004. Pelphrey, K.A., Viola, R.J., and McCarthy, G. When strangers pass: Processing of mutual and averted social gaze in the superior temporal sulcus. Psychological Science, 15, 598-603, 2004. Huettel, S.A., Song, A.W., and McCarthy G. Decisions under uncertainty: Probabilistic context influences activation of prefrontal and parietal cortices. Journal of Neuroscience, 25(13): 3304-3311, 2005. Morris, J.P., Pelphrey, K., and McCarthy G. Regional brain activation evoked when approaching a virtual human on a virtual walk. Journal of Cognitive Neuroscience, 17(11):1744-1752, 2005. |
