Binding in working memory and long-term memory: towards an integrated model

Abstract

Models of long-term and working memory assume various forms of binding processes. Long-term memory consolidation involves a process whereby memory representations are first bound by the hippocampus and certain surrounding areas. Then, a consolidation process is assumed whereby the binding role is transferred from the hippocampus to neocortical sites, a movement from hippocampal-cortical to cortico-cortical connectivity. Many models of working memory assume that high levels of neural synchrony or simultaneous firing rate represent its memory contents. Short-term binding is thus accomplished through firing rates and temporal correlations of firing that emerge from the complex interplay of existing connections and from the effects of the recent activation history (from ‘thinking’, planning, perception, setting of motor movements, etc.). In a few seconds this content can in principle be transferred to long-term memory, specifically to the hippocampus, via Hebbian plasticity. In this paper, we will present a binding perspective from two connectionist models developed by us: a model of binding in working memory and a model of trace binding in long-term memory consolidation. We will delineate four different neurodynamical binding mechanisms, describe and discuss these two models of short-term and long-term memory binding, and finally present ideas for an integrated model architecture of binding in memory.