9511365 Edward Keller Saccadic eye movements are among the most rapid and accurate movements that humans are capable of executing, but the mechanical system producing eye movements is relatively simple in comparison to limb movements. Therefore, the saccadic system has served as a model system for gaining insights into the general problem of how the brain generates motor control. This project is to examine how two-dimensional sensory information from the visual system is turned into the highly distributed neuronal control signals from the brain that move the eyes to produce highly efficient examination of our surroundings, for example, during reading. These scientists will use artificial neural networks and optimization techniques to model how movement commands are developed in neural structures in the brain such as the nonlinear maps of visual space and maps of the motor space. Saccades are controlled by internal feedback about eye position during a movement, but not direct visual input, because the visual messages are too slow to provide compensation during the saccade. These scientists are testing their hypothesis that shifts in the populations of active cells in these maps in the brain are driven by the internal feedback signal and actively control the trajectory of the eyes during the movement. Their work will help us to understand both how eye movements and other kinds of movement, such as fine motor control or human gait, are controlled by the brain.
