Nicholas Hatsopoulos, Ph.D. Associate Professor Department of Organismal Biology and Anatomy Committee on Neurobiology Chair, Committee on Computational Neuroscience Home page
Motor cortex physiology My research focuses on the neural basis of motor control and learning. I am investigating what features of motor behavior are encoded and how this information is represented in the collective activity of neuronal ensembles in the motor cortex. I am also interested in what way these representations change as motor learning occurs. To answer these questions, the electrical discharge of many motor cortical neurons is recorded using multi-electrode arrays while animals perform various motor behaviors. Novel representational schemes have been investigated that depend on the statistical interactions among groups of neurons. The encoding properties of individual motor cortical neurons are being studied to determine how these single cell properties relate to higher-order representations involving groups of neurons. The possibility that changes in functional connectivity among neurons may occur during motor learning is also being explored. Finally, various decoding strategies are being developed by which the activities of neural ensembles can be used to predict the behavior of the animal. Ultimately, this research may lead to neural prosthetic technologies that will allow people with spinal injuries to use brain signals to control either a cursor on a computer screen, a robot arm, or even their own arm, thereby bypassing the injured spinal cord.  More information can be found on the lab webpage. References Donoghue, J.P., Sanes, J.N., Hatsopoulos, N.G. and Gaal, G. (1998). Neural discharge and local field potential oscillations in primate motor cortex during voluntary movements. Journal of Neurophysiology, 77: 159-173.  Hatsopoulos, N.G., Ojakangas, C.L., Paninski, L. and Donoghue, J.P. (1998). Information about movement direction obtained by synchronous activity of motor cortical neurons. Proceedings of the National Academy of Sciences, 95: 15706-15711.  Maynard, E.M., Hatsopoulos, N.G., Ojakangas, C.L., Acuna, B.D., Sanes, J.N., Normann, R.A. and Donoghue, J.P. (1999). Neuronal interactions improve cortical population coding of movement direction. Journal of Neuroscience, 19: 8083-8093.  Hatsopoulos, N.G., Harrison, M.T. and Donoghue, J.P. (in press). Representations based on neuronal interactions in motor cortex. In M. Nicolelis. Progress in Neurobiology.  Oram, M.W., Hatsopoulos, N.G., Richmond, B.J., and Donoghue, J.P. (in press). Excess synchrony in motor cortical neurons provides direction information that is redundant with the information from coarse temporal response measures. Last updated 12/2//08