Can Anodal Transcranial Direct Current Stimulation Increase Steady-State Visual Evoked Potential Responses?

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Steady-state visual evoked potential (SSVEP) detection is challenging for individuals with low signal-to-noise ratio (SNR).
• This limitation impacts the efficacy of brain-computer interface (BCI) applications relying on SSVEP signals.

Purpose of the Study:

• To investigate the modulatory effect of anodal transcranial direct current stimulation (tDCS) on SSVEP responses.
• To determine if tDCS can enhance SSVEP signal quality, specifically SNR and amplitude.

Main Methods:

• A within-subjects design comparing active tDCS and sham tDCS sessions (20 minutes each).
• Electroencephalogram (EEG) data were collected to measure SSVEP SNR and amplitude before and after stimulation.
• Participants underwent two separate experimental sessions on different days.

Main Results:

• Anodal tDCS significantly enhanced EEG features (SNR and amplitude) in electrodes with low pre-tDCS SNR.
• The enhancement effect was not significant for electrodes that already possessed higher SNR values.
• tDCS demonstrated a targeted improvement for individuals with weaker SSVEP signals.

Conclusions:

• Anodal tDCS of the visual cortex is a potential method to improve SSVEP detection.
• This technique may be particularly effective for individuals experiencing low SSVEP SNR, thereby improving BCI performance.
• tDCS offers a promising non-invasive approach to boost visual evoked potentials.