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Updated: Jan 24, 2026

The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram
Published on: October 10, 2025
Modulation of large-scale cortical coupling by transcranial alternating current stimulation.
Bettina C Schwab1, Jonas Misselhorn1, Andreas K Engel1
1Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Germany.
Bifocal transcranial alternating current stimulation (tACS) can modulate brain connectivity. Phase-specific electrical fields influence long-range brain coupling, offering a new tool for neuropsychiatric disorder research.
Area of Science:
- Neuroscience
- Cognitive Science
- Brain Stimulation
Background:
- Long-range functional brain connectivity is crucial for cognition.
- Altered connectivity is observed in neuropsychiatric disorders.
- Noninvasive brain stimulation offers a potential method to modulate brain coupling.
Purpose of the Study:
- To determine if transcranial alternating current stimulation (tACS) influences human brain functional connectivity.
- To investigate the frequency and spatial specificity of tACS effects on connectivity.
Main Methods:
- Bifocal high-definition tACS was applied in-phase, anti-phase, and jittered-phase conditions.
- Electroencephalography (EEG) aftereffects were analyzed in sensor and source space.
- Stimulation involved identical, phase-reversed, or continuously shifting electric fields between hemispheres.
Main Results:
- In-phase stimulation resulted in greater EEG connectivity changes compared to anti-phase or jittered-phase conditions.
- Connectivity effects were specific to the stimulated alpha-band frequency.
- Effects were localized to occipito-parietal areas and persisted up to 120 seconds post-stimulation.
Conclusions:
- The relative phase of bifocal alpha-tACS significantly modulated alpha-band connectivity between targeted regions.
- Phase-specific influence of electric fields on neural activity was demonstrated.
- Bifocal high-definition tACS is proposed as a tool for manipulating long-range cortico-cortical coupling.
More Related Videos
11:11Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation
Published on: September 23, 2017
06:51Concurrent Electroencephalography Recording During Transcranial Alternating Current Stimulation tACS
Published on: January 22, 2016
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