Leon N Cooper

Ph.D., Columbia University, 1954
Thomas J. Watson,Sr.
Professor of Science
Departments of Physics and Neuroscience
718 Barus & Holley
Tel. (401) 863-2585

Research Summary

A goal of our research is to elucidate the biological mechanisms that underly learning and memory: to find principles of organization that can account both for experimental data on the cellular level and, when applied to large numbers of neurons that receive sensory and/or interneuronal information, for various higher level systems properties. Networks of neurons already have been constructed that can organize themselves to display some cognitive properties. Although these are still primitive compared to what animals or even machines in some cases can presently do, it is of significance that these networks are self-organizing, that the global cognitive properties are the result of local modifications of the network components - learning (so to speak) on a cellular level. This learning comes about through the modification of synaptic junctions (connections) between neurons. A crucial hypothesis concerns the form of this synaptic modification. We attempt to test our ideas concerning synaptic modification by applying them to the development of selectivity and ocular dominance in cat visual cortex, where much experimental data has been obtained in the last twenty years. This leads to a theory of synaptic evolution based on sets of coupled non-linear stochastic differential equations. Analysis and computer simulations are used to investigate the agreement of the theory with classical experimental results.

Publications

Cooper, L.N. and Law, C.C. (1994) Formation of Receptive Fields in Realistic Visual Environments According to the Bienenstock, Cooper, and Munro (BCM) Theory, Proc. Nat. Acad. Sci., USA, Vol. 91 pp. 7797-7801.
Cooper, L.N and C.L. Scofield (1988) Mean field approximation in neural networks. Proceedings of the National Academy of Sciences, USA 85:1973.
Bear, M.F., Cooper, L.N and Ebner, Ford F. (1987) A physiological basis of a theory for synapse modification. Science 237:4248.
Bienenstock, E.L., Cooper, L.N and Munro, P. (1982) Theory for the development of neuron selectivity: Orientation selectivity and binocular interaction in visual cortex. J. Neurosci. 2:23-48.
Clothiaux, E. Cooper, L.N, and Bear, M.F. (1991) Synaptic plasticity in visual cortex: Comparison of theory with experiment. J. Neurophysiology 66(5).66: 1785-1804.
Cooper, L.N and Intrator, N. (1992) Objective function formulation of the BCM theory of visual cortical plasticity: Statistical connections, stability conditions. Networks 3:5-17.
Comparison of experimental observations with BCM F function for synaptic modification. Dudek, S.M. and Bear, M.F. (1992). Homosynaptic long-term depression in area CA1 of hippocampus and the effects on NMDA receptor blockade. Proc. Natl. Acad. Sci., 89:4363-4367.