Hebbian fast plasticity and working memory

TL;DR

This paper reviews the shift from persistent activity models to fast Hebbian plasticity as a mechanism for working memory, highlighting recent experimental evidence and theoretical developments.

Contribution

It provides a comprehensive overview of how fast Hebbian plasticity offers a promising alternative to traditional persistent activity models for working memory.

Findings

Fast Hebbian plasticity can support activity-silent working memory.

Recent experimental evidence supports the role of rapid synaptic changes in WM.

Theoretical models now incorporate fast Hebbian mechanisms for multi-item WM.

Abstract

Theories and models of working memory (WM) were at least since the mid-1990s dominated by the persistent activity hypothesis. The past decade has seen rising concerns about the shortcomings of sustained activity as the mechanism for short-term maintenance of WM information in the light of accumulating experimental evidence for so-called activity-silent WM and the fundamental difficulty in explaining robust multi-item WM. In consequence, alternative theories are now explored mostly in the direction of fast synaptic plasticity as the underlying mechanism.The question of non-Hebbian vs Hebbian synaptic plasticity emerges naturally in this context. In this review we focus on fast Hebbian plasticity and trace the origins of WM theories and models building on this form of associative learning.