RESEARCH FOCUS
Cognitive deficits in schizophrenia are profoundly disabling and not adequately treated by current
medication regimens. Identifying the neural circuitry that underlies cognitive deficits in schizophrenia can guide investigations of
neuropathology 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 schizophrenia. 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 cortex to cognition. The prefrontal cortex is thought to mediate executive function, which encompasses diverse cognitive abilities involved in the control and optimization of voluntary action. These include holding and manipulating information in 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 behavior in order to optimize performance and learn from mistakes.
Our tools include functional and structural MRI, 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 schizophrenia. We are using DTI to examine the microstructural integrity of white matter pathways that support cognition. 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 procedural learning and memory consolidation. We are investigating the basis of this failure using overnight polysomnography and behavioral studies.
OUR TOOLS
fMRI
Functional 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.
DTI
Diffusion 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.
MEG
Magnetoencephalography 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.
CONTACT
Dara S. Manoach, Ph. D.
149 13th Street, Room 2608
Charlestown, MA 02129 USA
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