Modulation of vigilance/alertness using beta (30 Hz) transcranial alternating current stimulation

Chu, Zhongliang; Wang, Rui; Zhou, Tianyi · 2025 · Crossref

DOI: 10.3389/fnins.2025.1445006

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates the modulation of vigilance and alertness using beta-frequency (30 Hz) transcranial alternating current stimulation (tACS). Vigilance, defined as the ability to sustain attention over prolonged periods, typically declines over time, leading to decreased performance in response times and accuracy. While previous research has explored tACS for enhancing vigilance, findings regarding the optimal stimulation parameters, specifically the comparison between "online" (during task) and "offline" (post-stimulation) application, and the efficacy of different cortical targets, remain inconsistent. This research aims to determine whether beta tACS improves vigilance performance and to identify the most effective stimulation montage and timing pattern. The authors analyzed an open-source dataset containing high-density electroencephalography (EEG), physiological, and behavioral data from 15 neurologically typical participants. The study focused on Experiment 2 of the original dataset, where participants performed a continuous compensatory tracking task (CTT), a standard measure of vigilance. Participants underwent two sessions involving High-Definition tES (HD-tES) targeting either the frontal region (F30) or the motor region (M30) with 30 Hz stimulation. Each session included a 20-minute baseline period followed by 20 trials of 30-second stimulation epochs. Behavioral performance was assessed by measuring the deviation of a cursor from a target, with lower deviation indicating better vigilance. Data were categorized into "online" (during stimulation) and "offline" (between stimulation trials) conditions. Statistical analyses included Wilcoxon signed-rank tests for baseline comparisons and two-way ANOVAs to evaluate the effects of stimulation montage and pattern. The results demonstrated that beta tACS significantly improved vigilance performance compared to baseline. Specifically, both online and offline tACS conditions showed improvements, but online tACS had a greater effect than offline tACS. Furthermore, stimulation targeting the frontal region produced a more significant improvement in vigilance performance than stimulation targeting the motor region. The interaction between stimulation pattern and montage was not significant. Notably, offline motor tACS was associated with vigilance decrements, whereas online motor tACS enhanced performance. The frontal stimulation consistently reduced correct deviation and deviation variability, indicating more stable and precise attentional control. These findings suggest that beta-frequency tACS, particularly when applied online to the frontal cortex, is an effective non-invasive neuromodulation technique for counteracting vigilance decrements. The study supports the theoretical view that beta oscillations play a crucial role in sustained attention and that frontal networks are key to maintaining alertness. The superior efficacy of online stimulation implies that neural entrainment during the task is more beneficial than short-term aftereffects. These results contribute to the development of closed-loop tACS interventions for enhancing cognitive performance in professions requiring prolonged vigilance.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-nvidia on 2026-08-10; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• neuro workload indices