# The Instantaneous Effect and Its Mechanism of Transcranial Direct Current Stimulation on Working Memory Based on Delta and Gamma Band Electroencephalography Characteristics

## TL;DR

This study explores how transcranial direct current stimulation affects working memory by analyzing brainwave patterns in healthy individuals.

## Contribution

The study reveals how tDCS modulates EEG activity in delta and gamma bands during working memory tasks.

## Key findings

- tDCS increased gamma band power and decreased delta band power in EEG signals.
- Delta–gamma phase–amplitude coupling was reduced during working memory tasks with tDCS.
- Brain network metrics like node degree and clustering coefficient differed between active and sham tDCS.

## Abstract

Background: Working memory (WM) is a critical component of cognitive performance. Although transcranial direct current stimulation (tDCS) is a promising neuromodulation technique, its effect on working memory in healthy individuals remains unclear. Methods: In this study, EEG signals were recorded from different groups (working memory group, tDCS group, and sham group) and analyzed using phase–amplitude coupling, power spectral density, and brain network analysis to investigate the effect and mechanism of tDCS on working memory tasks in healthy individuals. Results: The results showed that in the tDCS group, the power spectral density of the EEG was increased in the gamma band and decreased in the delta band, while the delta–gamma phase–amplitude coupling was also decreased during the working memory task. Meanwhile, brain network analysis indicated significant differences in the node degree and clustering coefficient between the active and sham stimuli. Conclusions: Despite the absence of immediate behavioral improvements, these results suggest that tDCS could significantly modulate working memory-related EEG activity.