Neurophysiology of the primate hippocampus leading to a model of its functions in episodic and spatial memory

Recordings from single hippocampal neurons in locomoting macaques reveal that some cells are tuned to "spatial view". Other neurons respond to objects, or a combination of an object and its spatial position, forming the basis for an attractor model of episodic memory combining continuous and discrete representations which is described. Spatial view cells (in conjunction with whole body motion cells in the primate hippocampus, and head direction cells in the primate presubiculum (R. G. Robertson et al., 1999)) would be useful as part of a spatial navigation system, for which they would provide a memory component. Given that idiothetic (self-motion) cues such as eye movements update the spatial view representation in the dark, path integration as well as memory is implemented. In a model of this, it is proposed that the hippocampal system incorporates a continuous attractor network for the spatial representation that can be moved in the state space by idiothetic inputs (E. T. Rolls et al., 2002), (S. M. Stringer et al., 2002).