Professor Bijoy K. Ghosh
Department of Systems Science and Mathematics
St. Louis, Missouri
This talk presents a dynamic model of a spiking neuron using the wellknown Hodgkin Huxley model and many of its simplifications. We demonstrate that the spikes encode analog signals that can be used both as a control signal as well as sensory visual signal for example in the visual cortex. We consider a population of neurons and show how they can be used in controlling the movement of human arm in a horizontal plane The parameters of the desired trajectory as well as the system variables (angle and velocities) are encoded using these populations. The underlying mathematics including integration, differentiation and other algebraic relationships, has been done at the level of neuronal activity. We also study how a population of neurons can be used to model the dynamic interaction of cells in the visual cortex of freshwater turtles. Using our simulation model, we are able to reproduce wave of activity that propagates across the cortex. Using principal component analysis on these waves, we show how these waves can discriminate between various visual inputs to the retina of the turtle.