| | Staff Scientists and Clinicians
| Sean Marrett, Ph.D. |
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Sean
Marrett is a staff scientist in the Functional
MRI Facility in the Intramural Research Program,
National Institute of Mental Health in Bethesda Maryland.
He attended college and graduate school at McGill University in Montreal, Canada. His
original training was in electrical engineering (B.Eng, M. Eng) while his doctoral training (from the
Montreal Neurological Institute) was in neurological sciences. His post-doctoral work was at the
Massachusetts General Hospital NMR Center where he completed a Human Frontiers long-term
fellowship with Roger Tootell and Bruce Rosen in 1999. He joined Dr. Bandettini and the FMRIF at the
NIMH in 2000.
Dr. Marrett's responsibilities for the FMRIF/NIMH include the general computational
infrastructure as well as the subject interface issues, stimulus delivery and monitoring
behavior in the magnet. His research prior to the NIH was focused on neurovascular coupling
and studies of cerebral metabolism using position emission tomography and functional MRI.
In addition he co-authored several key papers in the statistical analysis of brain imaging
data, including the first systematic analysis of functional mapping using the theory of
Gaussian random fields (with Keith Worsley and Alan Evans) and also co-authored the
first study of the cortical representation of pain. While Dr. Marrett was at the Harvard
NMR Center he was part of the group that developed a software package for cortical surface
analysis (led by Anders Dale and Bruce Fischl) and he has helped make these techniques
available at the NIMH.
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| Research Interests |
| Dr. Marrett's main interests is the functional organization of visual perception. He is pursuing collaborations within the Laboratory of Brain and Cognition with Dr. Hauke Heekeren and Dr. Leslie Ungerleider examining the physiology of perceptual decision making in early visual areas as well as in prefrontal cortex using random dot stimulus and multiple response modalities. The key goal of this work is to evaluate the representation of perceptual decision variables in extrastriate, parietal and frontal cortex. He is also involved with a collaboration with the NINDS LFMI with Dr. Alan Koretsky and Adam Thomas (FMRIF) in which they are developing methods for high resolution laminar analysis of the myeloarchitecture of visual cortex and relating these anatomical studies to in-vivo functional images. A specific goal of this work is to relate the anatomical and functional boundaries in early visual cortex. |
| Representative Selected Recent Publications: |
- Heekeren HR, Marrett S, Bandettini PA, Ungerleider LG.:
A general mechanism for perceptual decision-making in the human brain.
Nature, Oct 14;431(7010):859-62, 2004.
- Barbier EL, Marrett S, Danek A, Vortmeyer A, van Gelderen P, Duyn J, Bandettini P, Grafman J, Koretsky AP.:
Imaging cortical anatomy by high-resolution MR at 3.0T: detection of the stripe of Gennari in visual area 17.
Magn Reson Med., Oct;48(4):735-8, 2002.
- Gjedde A, Marrett S.:
Glycolysis in neurons, not astrocytes, delays oxidative metabolism of human visual cortex during sustained checkerboard stimulation in vivo.
J Cereb Blood Flow Metab., Dec;21(12):1384-92, 2001.
- Hoge RD, Atkinson J, Gill B, Crelier GR, Marrett S, Pike GB.
Linear coupling between cerebral blood flow and oxygen consumption in activated human cortex.
Proc Natl Acad Sci USA., Aug;3;96(16):9403-8, 1999.
- Tootell RB, Hadjikhani N, Hall EK, Marrett S, Vanduffel W, Vaughan JT, Dale AM.
The retinotopy of visual spatial attention. Neuron., Dec;21(6):1409-22. PMID 9883733, 1998
- Worsley KJ, Marrett S, Neelin P, Vandal AC, Friston KJ, Evans AC
A unified statistical approach for determining significant signals in images of cerebral activation.
Human Brain Mapping, (1):58-73, 1996.
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