Our research focuses on investigating the neural bases of high-level cognitive processes such as working memory and executive control. These aims are achieved through several different experimental approaches and methodologies. First, we employ a neuroimaging method called functional MRI (fMRI) to identify the neuroanatomical substrates and temporal dynamics of various cognitive processes in normal human subjects. A key focus has been the cognitive functions supported by prefrontal cortex. Second, we have been investigating the role of the dopaminergic system in working memory and frontal lobe function. This aim is achieved with pharmacological studies during which direct dopaminergic agonists are administered to normal human subjects, as well as patients with frontal lobe lesions, to determine the effect of dopamine on cognition. Third, we perform behavioral studies in patient populations with frontal lobe dysfunction (e.g. stroke, head injury, Parkinson's disease) in order to further understand the mechanisms that underlie working memory. Finally, we are interested in understanding the physiological bases of normal human aging, and the effects of normal aging on prefrontal function.
Gazzaley A, Cooney J, McEvoy K, Knight RT, D’Esposito M. Top-down modulation of visual processing: converging fMRI and ERP evidence, Journal of Cognitive Neuroscience, 17:507-17, 2005.
Cools R, Sheridan M, Jacobs EC, D'Esposito M. Impulsive personality predicts dopamine-dependent changes in fronto-striatal activity during component processes of working memory, Journal of Neuroscience, 27:5506-14, 2007.
Badre D, Hoffman J, Cooney JW, D’Esposito M. Hierarchical cognitive control deficits following damage to the human frontal lobe, Nature Neuroscience, 12:515-22, 2009.
Gratton C, Nomura E, Perez F, D’Esposito M. Focal brain lesions cause widespread disruption of the modular organization of the brain, Journal of Cognitive Neuroscience, 24(6):1275-85, 2012.
Lee TG, D’Esposito M. The dynamic nature of top-down signals originating from prefrontal cortex: A combined fMRI-TMS study, Journal of Neuroscience, 32:15458-66, 2012.
Mark T. D'Esposito