Temporally coherent perturbation of neural dynamics during retention alters human multi-item working memory

Abstract

Temporarily storing a list of items in working memory (WM), a fundamental ability in cognition, has been posited to rely on the temporal dynamics of multi-item neural representations during retention. Here, we develop a "dynamic perturbation" approach to manipulate the relative memory strength of a list of WM items, by interfering with their neural dynamics during the delay period in a temporally correlated way. Six experiments on human subjects confirm the effectiveness of this WM manipulation method. A computational model combining continuous attractor neural network (CANN) and short-term synaptic plasticity (STP) principles further reproduces all the empirical findings. The model shows that the "dynamic perturbation" modifies the synaptic efficacies of WM items through STP principles, eventually leading to changes in their relative memory strengths. Our results support the causal role of temporal dynamics of neural network in mediating multi-item WM and offer a promising, non-invasive approach to manipulate WM.