Figure 3.

Episodic memory of spatial views can involve encoding and retrieval of associations of individual spatial locations with the viewpoint from different spatial locations. In this example, the spatiotemporal trajectory is encoded and retreived by the interaction of speed coding and direction coding that drives the firing of grid cells. The grid cells can update the firing of place cells that are associated with individual spatial views. Alternately, the individual spatial views can update the firing of place cells that drive grid cells. Hebbian modification (bidirectional arrow) allows encoding (top) and retrieval (bottom) of associations of each place cell with a distinct spatial view, which can be represented by a single relational code of features in the environment so that neurons responding to the individual position and direction on a trajectory can encode associations that allow retrieval of the visual feature angle of specific objects in the visual environment.