Transcranial direct current stimulation over the frontal eye field has no effect on visual search performance

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Top-down attention is crucial for daily functioning.
• Attention deficits, common after brain lesions, necessitate effective therapies.
• Transcranial direct current stimulation (tDCS) is explored as a non-invasive brain stimulation therapy.

Purpose of the Study:

• To investigate the robustness of previous findings suggesting tDCS over the frontal eye field (FEF) enhances visual search performance.
• To determine if anodal tDCS over the FEF reliably improves top-down attention-guided visual search in healthy participants.

Main Methods:

• Two pre-registered experiments were conducted.
• Experiment 1: Anodal tDCS applied over the right FEF.
• Experiment 2: Anodal tDCS applied over the left FEF with visual search field size manipulation.

Main Results:

• Neither experiment reproduced previous findings of enhanced visual search performance with tDCS.
• Bayesian statistics provided evidence against reliable improvements in top-down attention-guided visual search.
• No significant enhancement in visual search was observed due to FEF tDCS.

Conclusions:

• The current findings do not support tDCS over the FEF as a strong therapeutic approach for attention disorders in healthy individuals.
• While potential effects in patient populations warrant further investigation, the efficacy in healthy participants is not demonstrated.
• Robust evidence for tDCS over FEF improving visual search in healthy individuals is lacking.