Anodal tDCS Over the Left Frontal Eye Field Improves Sustained Visual Search Performance

Area of Science:

• Neuroscience
• Cognitive Psychology
• Human Factors Engineering

Background:

• Monotonous tasks lead to vigilance decrement, increasing accident risks in critical industries like aerospace and nuclear.
• Sustained attention is vital for tasks requiring continuous monitoring, and its decline can have severe consequences.
• Cognitive enhancement and ergonomic research necessitate methods to buffer vigilance decrements in visual search.

Purpose of the Study:

• To evaluate the efficacy of anodal transcranial direct current stimulation (tDCS) targeting the left frontal eye field (FEF).
• To determine if tDCS can improve performance in sustained visual search tasks.
• To investigate the online and after-effects of tDCS on vigilance.

Main Methods:

• Twenty-seven healthy participants underwent a 40-minute sustained visual search task.
• Participants received either anodal or sham transcranial direct current stimulation (tDCS) at 2 mA for 28.8 minutes.
• Performance metrics, including d' (hit rate) and accuracy, were recorded during and after stimulation.

Main Results:

• Anodal tDCS significantly enhanced d' and accuracy compared to sham stimulation during the initial 0-19.2 minute intervals.
• A significant improvement in d' was observed for the anodal tDCS group 10 minutes after stimulation cessation.
• These findings indicate an immediate and sustained positive effect of tDCS on visual vigilance.

Conclusions:

• Anodal tDCS applied to the left FEF is effective in mitigating the decline in visual vigilance performance.
• The intervention appears to buffer cognitive resource depletion during prolonged visual search tasks.
• This approach holds potential for cognitive enhancement and improving safety in vigilance-dependent occupations.