Cell Assemblies (CAs) are the neural basis of both long and short term memories. CAs, whose neurons persistently fire, are active short term memories while the neurons are firing, and the memory ceases to be active when the neurons stop firing. This paper provides simulations of excitatory spiking neurons with small world topologies that persist for several hundred milliseconds. Extending this model to include short term depression allows the CA to persist for several seconds, a reasonable psychological duration. These CAs are combined in a simple associative memory so that when three CAs are associated, ignition of two causes the third to ignite, while pairs of unassociated CAs do not lead to the ignition of other CAs. This mechanism has a larger capacity than a Hopfield net. A discussion of the current psychological theories, other mechanisms for short term memory, the strengths and weaknesses of the paper’s simulated models, and proposed challenges are also provided.
Published Date: 2023-07-21; Received Date: 2023-06-21