Cognitive deficits in neuropsychiatric disorders are profoundly disabling and not adequately treated by current medication regimens. Identifying the neural circuitry that underlies cognitive deficits can guide investigations of neuropathology, genetic mechanisms, and the development of targeted interventions. This laboratory's research program aims to elucidate the neural bases of cognitive function in health so that we can identify how cognition breaks down in neuropsychiatric disorders. While schizophrenia is our primary focus, we also study individuals with autism spectrum disorder and obsessive-compulsive disorder.
We are particularly interested in the contributions of the prefrontal and anterior cingulate cortex to cognition. These regions mediate executive functions, a diverse set of cognitive abilities involved in the control and optimization of behavior. This includes holding and manipulating information online in your mind for brief periods, inhibiting reflexive actions in order to permit flexible, non-reflexive responding, switching between one activity and another at will, and monitoring the consequences of your behavior so that you can optimize your performance and learn from your mistakes.
Our tools include functional MRI (fMRI), diffusion tensor imaging (DTI), saccadic measurements, and magnetoencephalography (MEG). We use these tools in complementary ways to achieve a high degree of spatial and temporal precision. This allows us to pinpoint when and where in the brain cognitive processes go awry in neuropsychiatric disorders. We are using structural MRI techniques to examine structural correlates of abnormal function. A separate line of inquiry focuses on understanding the role of sleep in consolidating new learning. Patients with schizophrenia show a failure of sleep-dependent memory consolidation. We are investigating the basis of this failure using overnight polysomnography and behavioral studies.
fMRIFunctional magnetic resonance imaging allows scientists to take pictures of brain activity. Unlike standard MRI scans, which only show the structure or anatomy of the brain, fMRI actually shows the areas which are active while performing a specific task. fMRI also allows to examine the differences in brain function or activity caused by certain brain disorders, such as schizophrenia.
DTIDiffusion tensor imaging provides information regarding the structural integrity of white matter pathways in the brain by measuring the molecular diffusion of water in brain tissue. Diffussion is influenced by myelin density, the number of myelinated fibers, and axonal membrane integrity. Thus, DTI is an indirect measure of the structural integrity of white matter and is sensitive to alterations in tissue properties that conventional structural magnetic resonance imaging does not detect.
MEGMagnetoencephalography measures magnetic fields on the scalp that are generated by the communication of nerve cells in the brain. While it does not allow us to pinpoint the exact location of activity in the brain, it provides very detailed information about the timing of this activity. This makes it a good complement to fMRI, which provides more precise information about location.
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