Predictions derived from modelling the hippocampal role in navigation

A computational model of the lesion and single unit data from navigation in rats is reviewed. The model uses external (visual) and internal (odometric ) information from the environment to drive the firing of simulated hippoca mpal place cells. Constraints on the functional form of these inputs are dr awn from experiments using an environment of modifiable shape. The place ce ll representation is used to guide navigation via the creation of a represe ntation of goal location via Hebbian modification of synaptic strengths. Th e model includes consideration of the phase of firing of place cells with r espect to the theta rhythm of hippocampal EEG. A series of predictions for behavioural and single-unit data in rats are derived from the input and out put representations of the model.