M.D., University of Toronto
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. Another related line of my research examines the role of synchronous, oscillatory neuronal activity in supporting cognitive control and sensory 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 and sensory processes. We use EEG and MEG during behavioral paradigms to probe such associations and computational modeling studies to understand the mechanisms of oscillations. My research in normal cognition is also applied to understanding the disturbances 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.
- Richard, Annette E., Carter, C.S. Cohen, J.D., Cho, R.Y. (in press). Persistence, diagnostic specificity and genetic liability for context-processing deficits in schizophrenia. Schizophrenia Research.
- Komek, K., Ermentrout, G.B., Walker, C.P., Cho, R.Y. (2012). Dopamine and gamma band synchrony in schizophrenia: Insights from computational and empirical studies. European Journal of Neuroscience. 36(2), 2146-2155.
- Frankle, W.G., Cho, R.Y., Mason, N.S., Chen, C., Walker, C., Lewis, D.A., Mathis, C.A., Narendran, R., (2012). [11C]flumazenil binding is increased in a dose-dependent manner with tiagabine induced elevations in GABA levels. PloS One. 7(2):e32443.
- Forster, S.E., Carter, C. S., Cohen, J.D., Cho, R.Y.* (2011). Parametric Manipulation of the Conflict Signal and Control-State Adaptation. Journal of Cognitive Neuroscience. 23(4), 923-35.
- Kieffaber, P., Cho, R. Y. (2010). Cortical Gamma-band Oscillations Elicited by Implicit Probability Cues in the Preparing to Overcome Prepotency (POP) Task. Cognitive, Affective and Behavioral Neuroscience. 10(4), 431-440.
- Takahashi, T., Cho, R.Y.*, Mizuno, T., Kikuchi, M., Murata, T., Takahashi, K., Wada, Y. (2010). Antipsychotics reverse abnormal EEG complexity in neuroleptic-naive schizophrenia: A multiscale entropy analysis. Neuroimage. 51(1), 173-82.
- Cho, RY, Orr, JM, Cohen, JD, Carter, CS. (2009) 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. (2008). Subunit-selective modulation of GABAA receptor neurotransmission and cognition in schizophrenia. Am J Psychiatry.
- 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.
- 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.