Robotic and Neuronal Simulation of Hippocampal Navigation

A robotic platform controlled by a neuronal simulation is presented for studying the mechanisms underlying the ring of hippocampal place cells and how they support navigation. The sensors on the robot provide visual, odometric and short-range proximity information which are combined to estimate the distance of the walls of the enclosure from the robot and its current heading direction. These inputs drive a neuronal simulation of the hippocampus in which the robot's location is represented as the ring of place cells. If a goal location is encountered, connection strengths are incremented between active place cells and a set of `goal cells' which guide subsequent navigation (Burgess et al., 1994), allowing the robot to return to goal locations. The system shows good agreement with actual place cell ring, and makes predictions regarding the ring of cells in the subiculum and the locus of search of rats after deformation of their environment.