Assistant Professor, Psychiatry& Psychology University of Pittsburgh Phone: 412-586-9250 Email: chory@upmc.edu Lab Website:http://kraepelin.wpic.pitt.edu/

M.D., University of Toronto

Research Interests

My research focuses on elucidating the architecture and dynamics of cognitive control mechanisms and how they are disturbed in serious mental illness such as schizophrenia. Cognitive control describes the ability to coordinate and appropriately bias cognitive processes in the service of goal-directed behavior. One line of my research investigates how the top-down influences are dynamically adjusted in response to the influences of stimulus and response history, changes in attentional state, and updates in task demands. A useful way of investigating the dynamics of these responses is to examine trial-to-trial adjustments. For instance, trials that incur processing conflict are known to elicit control adjustments on subsequent trials. We examine such adjustments using conflict and task-switching behavioral paradigms during EEG and fMRI acquisition to examine the brain areas and dynamics underlying these adjustments, and employ computational models to characterize and make predictions concerning our results.

Another related line of my research examines the role of synchronous, oscillatory neuronal activity in supporting cognitive control processes. Gamma-band oscillations have been associated with basic perception as well as higher-order cognitive processes such as attention and working memory. My research investigates the importance of synchronous oscillations to cognitive control processes such as the maintenance of task context information. We use EEG during behavioral paradigms to probe such associations and have begun computational modeling studies to understand the mechanisms by which oscillations may help in supporting the appropriate representations.

My research in normal cognition is also applied to understanding the disturbances in cognitive control in schizophrenia. We have ongoing behavioral, EEG and fMRI studies in schizophrenia, including studies of medication-naïve, first-episode schizophrenia patients, offering the unique opportunity to examine disturbances in cognition in the absence of such important confounds as medication effects and treatment chronicity. Employing our computational models of normal cognition, we are also exploring the consequences of principled ‘lesions’ to the models to shed light on the specific pathophysiologic processes that give rise to the cognitive impairments in schizophrenia.

Recent Publications

• Cho, RY, Orr, JM, Cohen, JD, Carter, CS. Generalized Signaling for Control: Evidence from Post-Conflict and Post-Error Performance Adjustments. J Exp Psychol Hum Percept Perform, (In press).
• Lewis, D, Cho, RY, Carter, CS, Eklund, K, Forster, S, Kelly, M, Montrose, D. Subunit-selective modulation of GABAA receptor neurotransmission and cognition in schizophrenia. Am J Psychiatry, (In press).
• Frankle, WG, Cho, RY,  Narendran, R, Mason, NS, Vora, S, Litschge, M, Price, JC, Lewis, DA, Mathis, CA. The Ability to Increase Extracellular GABA Predicts Frontal Cortical Gamma Synchrony. Neuropsychopharmacology, (In press).
• Cho RY, Konecky RO, Carter CS: Impairments in frontal cortical gamma synchrony and cognitive control in schizophrenia. Proc Natl Acad Sci USA 103: 19878-19883, 2006.
• Cho RY, Ford JM, Krystal JH, Laruelle M, Cuthbert B, Carter CS: Functional neuroimaging and electrophysiology biomarkers for clinical trials for cognition in schizophrenia. Schizophr Bull 31: 865 - 869, 2005.
• Snitz BE, MacDonald III A, Cohen JD, Cho RY, Becker T, Carter CS: Lateral and medial hypofrontality in first-episode schizophrenia: Functional activity in a medication-naïve state and effects of short-term atypical antipsychotic treatment. Am J Psychiatry 162(12): 2322-2329, 2005.
• Kerns JG, Cohen JD, MacDonald AW III, Cho RY, Stenger VA, Carter CS: Anterior cingulate conflict monitoring predicts adjustments in control. Science 303: 1023-1026, 2004
• Cho RY, Nystrom LE, Brown ET, Jones AD, Braver TS, Holmes PJ, Cohen JD: Mechanisms underlying performance dependencies on stimulus history in a two-alternative forced choice task. Cogn Affect Behav Neurosci 2(4): 283-299, 2002
• Jones AD, Cho RY, Nystrom LE, Cohen JD, Braver TS: A computational model of anterior cingulate function in speed response tasks: effects of frequency, sequence, and conflict. Cogn Affect Behav Neurosci 2(4): 300-317, 2002