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Apostolos P. Georgopoulos,
M.D., Ph.D.
Professor, Departments of Neuroscience and Neurology
omega@umn.edu |
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 Neurophysiology
of Motor Control and Cognition.
The long-term goals of the research in our laboratory are to elucidate
the neural mechanisms underlying cognitive processes in motor behavior
and to understand the intrinsic mechanisms of the cerebral cortex.
We pursue experimental psychological studies, neurophysiological
recordings, functional magnetic resonance imaging (MRI) at high
field (4 Tesla), and neural network modeling (using supercomputers)
to achieve these goals.
We carry out psychological studies in both human subjects and rhesus
monkeys. The tasks are cognitive-motor in nature and employ paradigms
of mental rotation, memory scanning, and visuomotor control of isometric
force trajectories generated by the arm. Functional MRI in human
subjects distinguishes the patterns of activation of brain areas
during performance of these tasks. Electrophysiological recordings
of the activity of single cells in motor and other areas of the
cerebral cortex are then conducted in behaving monkeys in order
to elucidate the brain mechanisms involved in these tasks. This
experimental arrangement provides for a direct study of the relations
between neuronal populations and behavior. We model the activity
in these neuronal populations using a massively interconnected neural
network to produce dynamically evolving trajectories under external
guidance and from memory. Finally, we use information theory as
a metrics-free analytical tool.
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Selected Publications
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Pardo PJ, Georgopoulos AP, Kenny JT, Stuve TA, Findling RL, Schulz SC.
Classification of adolescent psychotic disorders using linear discriminant analysis.
Schizophr Res. 2006 Jun 23; [Epub ahead of print] |
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Langheim FJ, Merkle AN, Leuthold AC, Lewis SM, Georgopoulos AP.
Dipole analysis of magnetoencephalographic data during continuous shape copying.
Exp Brain Res. 2006 Apr;170(4):513-21. Epub 2005 Nov 23. |
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Langheim FJ, Leuthold AC, Georgopoulos AP.
Synchronous dynamic brain networks revealed by magnetoencephalography.
Proc Natl Acad Sci U S A. 2006 Jan 10;103(2):455-9. Epub 2005 Dec 30. |
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Merchant H, Georgopoulos AP.
Neurophysiology of perceptual and motor aspects of interception.
J Neurophysiol. 2006 Jan;95(1):1-13. Review. |
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Wilson TW, Leuthold AC, Lewis SM, Georgopoulos AP, Pardo PJ.
Cognitive dimensions of orthographic stimuli affect occipitotemporal dynamics.
Exp Brain Res. 2005 Nov;167(2):141-7. Epub 2005 Nov 15. |
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Georgopoulos AP, Langheim FJ, Leuthold AC, Merkle AN.
Magnetoencephalographic signals predict movement trajectory in space.
Exp Brain Res. 2005 Nov;167(1):132-5. Epub 2005 Oct 29. |
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Crowe DA, Averbeck BB, Chafee MV, Georgopoulos AP.
Dynamics of parietal neural activity during spatial cognitive processing.
Neuron. 2005 Sep 15;47(6):885-91. |
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Chafee MV, Crowe DA, Averbeck BB, Georgopoulos AP.
Neural correlates of spatial judgement during object construction in parietal cortex.
Cereb Cortex. 2005 Sep;15(9):1393-413. Epub 2005 Jan 5. |
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Lewis SM, Jerde TA, Tzagarakis C, Gourtzelidis P, Georgopoulos MA, Tsekos N, Amirikian B, Kim SG, Ugurbil K, Georgopoulos AP.
Logarithmic transformation for high-field BOLD fMRI data.
Exp Brain Res. 2005 Sep;165(4):447-53. Epub 2005 Jul 15. |
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Gourtzelidis P, Tzagarakis C, Lewis SM, Crowe DA, Auerbach E, Jerde TA, Ugurbil K, Georgopoulos AP.
Mental maze solving: directional fMRI tuning and population coding in the superior parietal lobule.
Exp Brain Res. 2005 Sep;165(3):273-82. Epub 2005 Jun 7. |
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Merchant H, Battaglia-Mayer A, Georgopoulos AP
Neural Responses during Interception of Real and Apparent Circularly Moving Stimuli in Motor Cortex and Area 7a.
Cereb Cortex. 2004 Mar;14(3):314-331 |
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Merchant H, Battaglia-Mayer A, Georgopoulos AP
Neural responses in motor cortex and area 7a to real and apparent motion.
Exp Brain Res. 2004 Feb;154(3):291-307 |
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Crowe DA, Chafee MV, Averbeck BB, Georgopoulos AP
Neural activity in primate parietal area 7a related to spatial analysis of visual mazes.
Cereb Cortex. 2004 Jan;14(1):23-34 |
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Merchant H, Fortes AF, Georgopoulos AP
Short-term memory effects on the representation of two-dimensional space in the rhesus monkey.
Anim Cogn. 2003 Dec 11 (in press) |
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Lewis SM, Jerde TA, Tzagarakis C, Georgopoulos MA, Tsekos N, Amirikian B, Kim SG, Ugurbil K, Georgopoulos AP
Cerebellar activation during copying geometrical shapes.
J Neurophysiol. 2003 Dec;90(6):3874-87 |
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Amirikian B, Georgopoulos AP.
Modular organization of directionally tuned cells in the motor cortex: Is there short-range order?
Proc Natl Acad Sci U S A. 2003 Oct 14;100(21):12474-9 |
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Fortes AF, Merchant H, Georgopoulos AP
Comparative and categorical spatial judgments in the monkey: "high" and "low"
Anim Cogn. 2003 Oct 7 (in press) |
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