One-shot learning and robust recall with BTSP, a biological synaptic plasticity rule

Abstract

ABSTRACTRecent experimental studies in the awake brain have identified a rule for synaptic plasticity that is instrumental for the instantaneous creation of memory traces in area CA1 of the mammalian brain: Behavioral Time scale Synaptic Plasticity (BTSP). This one-shot learning rule differs in essential aspects from previously considered plasticity mechanisms. We introduce a transparent model for the core function of BTSP, and establish a theory that enables a principled understanding of the system of memory traces that it creates. Our theoretical predictions and numerical simulations show that BTSP is able to create a functionally powerful content-addressable memory without the need for high-resolution synaptic weights. Furthermore, it reproduces the repulsion effect of human memory, whereby traces for similar memory items are pulled apart to enable differential downstream processing. Altogether, our results create a link between synaptic plasticity in area CA1 of the hippocampus and its network function. They also provide a blueprint for implementing content-addressable memory with on-chip learning capability in highly energy-efficient crossbar arrays of memristors.