# Beta Power May Mediate the Effect of Gamma-TACS on Motor Performance

## TL;DR

This study investigates how gamma-frequency transcranial alternating current stimulation (tACS) affects motor performance and suggests that beta oscillations mediate this effect, enhancing understanding of individual variability in tACS outcomes.

## Contribution

It provides empirical evidence linking beta power modulation to gamma-tACS effects on motor performance, advancing knowledge of cross-frequency brain interactions.

## Key findings

- Beta power mediates gamma-tACS effects on motor performance
- Gamma-tACS influences low- and high-beta oscillations
- Individual variability in tACS effects may relate to beta oscillation differences

## Abstract

Transcranial alternating current stimulation (tACS) is becoming an important method in the field of motor rehabilitation because of its ability to non-invasively influence ongoing brain oscillations at arbitrary frequencies. However, substantial variations in its effect across individuals are reported, making tACS a currently unreliable treatment tool. One reason for this variability is the lack of knowledge about the exact way tACS entrains and interacts with ongoing brain oscillations. The present crossover stimulation study on 20 healthy subjects contributes to the understanding of cross-frequency effects of gamma (70 Hz) tACS over the contralateral motor cortex by providing empirical evidence which is consistent with a role of low- (12~-20 Hz) and high- (20-~30 Hz) beta power as a mediator of gamma-tACS on motor performance.