Episodic memory and cognitive map in a rate model network of the rat hippocampus

Abstract

The hippocampus of rodents seems to play a central role in navigation: place cells are prone to serve as elements of a cognitive map. The hippocampus of primates is apparently involved in episodic memory processes. Here we show how the hippocampi of different species (with their anatomy and physiology being considerably similar) can fulfill both purposes. A network was built from simple rate neurons, synaptic weights were modified by a batch version of the coincidence-based Bienenstock– Cooper–Munro learning rule. The network was trained with temporally contiguous sensory stimuli, and then tested in two different paradigms: (1) for navigational performance, place field profiles were evaluated to allow comparison with experimental data; (2) for memory performance, associative capability was assessed. The same neuron network was found to be able to show place cell properties and function as episodic memory, even when trained with non-topographical stimuli.