Neural dissociation of attention and working memory through inhibitory control

TL;DR

This study shows that attention and working memory are separate brain processes, with a specific brain region controlling which information is stored.

Contribution

The study provides causal evidence that attention and working memory encoding are dissociable processes mediated by inhibitory control in the supramarginal gyrus.

Findings

The supramarginal gyrus (SMG) is identified as a key region for dissociating attention from working memory encoding.

Neuromodulation experiments confirm that enhancing SMG activity strengthens inhibitory control over attentional representations.

Transcranial magnetic stimulation provides causal evidence supporting the dissociation with spatial precision.

Abstract

Attention and working memory (WM) have traditionally been considered closely linked processes with shared neural mechanisms. In information selection, attention is often conceptualized as a gatekeeper to WM, regulating which information is encoded and stored. Here, combining tasks specifically designed to separate attention from WM encoding with a multimodal approach, we provide converging neural and causal evidence that these processes are dissociable. Functional MRI identifies the supramarginal gyrus (SMG) as the key region enabling this dissociation, while dynamic causal modeling reveals the neural circuitry through which the SMG exerts inhibitory control over attentional representations, regulating their integration into WM. Furthermore, neuromodulation via transcranial direct current stimulation (tDCS) demonstrates that enhancing SMG activity strengthens this inhibitory control. A second tDCS experiment using varied stimuli confirms the generalizability of the effect. Finally, a transcranial magnetic stimulation (TMS) experiment provides further causal evidence with greater spatial precision. These findings challenge the long-standing view that attention and WM encoding form a continuous process, demonstrating instead that they constitute two dissociable neural processes of information selection.

Here, the authors combine brain imaging and non-invasive stimulation to show that attention and working memory are dissociable processes, with inhibitory control in the supramarginal gyrus gating what attended information reaches memory.

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