Related Experiment Video
Updated: Apr 23, 2026
Simultaneous EEG Monitoring During Transcranial Direct Current Stimulation
Published on: June 17, 2013
Transcranial Direct Current Stimulation Effects on Single and Paired Flash Visual Evoked Potentials
Gionata Strigaro1, Isabella Mayer2, Jui-Cheng Chen3
1Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale "A. Avogadro", Novara, Italy gionata.strigaro@gmail.com.
Transcranial direct current stimulation (tDCS) over the occipital cortex showed weak inhibitory effects on single flash visual evoked potentials (F-VEPs) but no impact on paired F-VEPs in healthy humans. Further research is needed to optimize tDCS efficacy.
Area of Science:
- Neuroscience
- Ophthalmology
- Neuromodulation
Background:
- Transcranial direct current stimulation (tDCS) effects on visual cortex excitability are debated.
- Paired flash visual evoked potentials (F-VEPs) are a sensitive measure of visual neural inhibition.
- Previous research has not investigated tDCS effects on F-VEPs in humans.
Purpose of the Study:
- To assess changes in single and paired F-VEPs during and after tDCS in healthy individuals.
- To explore the impact of anodal and cathodal tDCS on visual cortex excitability.
Main Methods:
- Twenty-six healthy volunteers underwent tDCS over the occipital cortex.
- Single and paired F-VEPs were recorded at various interstimulus intervals (8-90 Hz).
- Two experiments varied return electrode placement and recording timing (during/after stimulation).
Main Results:
- Experiment 1 showed no significant F-VEP changes after tDCS with scalp return electrode.
- Experiment 2 revealed anodal tDCS increased P2 latency and reduced single F-VEP 'late response' amplitude.
- Paired F-VEPs demonstrated no significant changes in either experiment.
Conclusions:
- Low-intensity anodal tDCS exhibits mild inhibitory aftereffects on single F-VEPs.
- tDCS did not significantly alter neural inhibition as measured by paired F-VEPs.
- Methodological improvements are necessary to enhance tDCS polarization efficacy for visual cortex studies.
