An associative memory model with probabilistic synaptic transmission

The associative net model of heteroassociative memory with binary-valued synapses has been extended to include recent experimental data that indicates that in the hippocampus one form of synaptic modification is a change in the probability of synaptic transmission [2]. Pattern pairs are stored in the net by a version of the Hebbian learning rule that changes the probability of transmission at synapses where the presynaptic and postsynaptic units are simultaneously active from a low base value to a high, modified value. Numerical calculations of the expected recall response have been used to assess the performance for different values of the base and modified probabilities. If there is a cost incurred with generating the difference between these probabilities, then the optimal difference is around 0.4. Performance can be greatly enhanced by using multiple cue presentations during recall.