Simulation of Human Episodic Memory by Using a Computational Model of the Hippocampus
Figure 2
Model of object-place association by using neural synchronization [43]. (a) Basic information flow of the model. (b) One-dimensional visual environment including three colored objects and grayscale background. (c) Neuronal representation of object and scene information. An association is represented by a combination of object feature and object-centered background that are encoded by a set of discrete and continuous vector patterns. (d) Encoding of visual input sequence with theta phase precession. In the plot, black bars indicate input and CA3 activities. Difference in input durations between objects and scenes results in a robust object-scene phase difference. (e) A schematic graph of resultant CA3 connection weight. A node denotes a population of CA3 units having same selectivity of visual features. The numbers in a node denote the selectivity of scene units of the node. For example, “23’’ indicates units activated during fixating on objects 2 and 3, while these are not activated during fixating on an object 1. Lines with an arrowhead indicate directional connections between unit populations. ((f), (g)) Retrieval in the hierarchical network. Gray nodes denote units that are activated initially, and , , and denote the time after giving initial activations. A set of object-place associations is sequentially activated as an activity propagation in the network.
