Associative memories

Associative memories might be represented by groups of strongly interconnected neurons, called neuronal assemblies. Recent experimental findings suggest that such assemblies are not static but composed of different neurons at different times [1]. A theoretical model reproducing these findings is given by drifting assemblies [2]: In a gradual process, assemblies exchange individual neurons between one another due to ever-present synaptic plasticity. So far, only single-layer networks of drifting assemblies have been considered. Biological neuronal assemblies are, however, thought to be distribu

…drift, is useless for the retrieval of associative memories learned several weeks prior. Howeve

In a standard model, associative memories are represented by assemblies of strongly interconnected neurons. It has recently been proposed that these assemblies are not static but drift freely in neural circuits. This explains experimental findings of changing memory representations. On the level of single neurons, assembly drift is reflected by characteristic dynamics: relatively long times of stable assembly membership interspersed with fast transitions. How can we mechanistically understand these dynamics? Here we answer this question by proposing simplified, reduced models. We first constru