Transcranial alternating current stimulation used to boost working memory

March 16, 2017

The fMRI scans show that stimulation “in beat” increases brain activity in the regions involved in task performance. On the other hand, stimulation “out of beat” showed activity in regions usually associated with resting. (credit: Ines Violante)




Keeping the beat

Violante and team targeted two brain regions — the middle frontal gyrus and the inferior parietal lobule — which are known to be involved in working memory.







Clinical use



The research was funded by the Wellcome Trust.

Abstract of Externally induced frontoparietal synchronization modulates network dynamics and enhances working memory performance

Cognitive functions such as working memory (WM) are emergent properties of large-scale network interactions. Synchronisation of oscillatory activity might contribute to WM by enabling the coordination of long-range processes. However, causal evidence for the way oscillatory activity shapes network dynamics and behavior in humans is limited. Here we applied transcranial alternating current stimulation (tACS) to exogenously modulate oscillatory activity in a right frontoparietal network that supports WM. Externally induced synchronization improved performance when cognitive demands were high. Simultaneously collected fMRI data reveals tACS effects dependent on the relative phase of the stimulation and the internal cognitive processing state. Specifically, synchronous tACS during the verbal WM task increased parietal activity, which correlated with behavioral performance. Furthermore, functional connectivity results indicate that the relative phase of frontoparietal stimulation influences information flow within the WM network. Overall, our findings demonstrate a link between behavioral performance in a demanding WM task and large-scale brain synchronization.