Transcranial photobiomodulation enhances visual working memory capacity in humans.

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• Transcranial photobiomodulation (tPBM) is a noninvasive technique showing potential for cognitive enhancement.
• The precise mechanisms by which tPBM modulates brain activity and impacts working memory (WM) are not fully understood.

Purpose of the Study:

• To investigate if tPBM can modulate brain activity and improve human working memory capacity.
• To determine the efficacy of specific tPBM parameters (wavelength and targeted brain region) for enhancing WM.

Main Methods:

• Participants received 1064-nm or 852-nm tPBM applied to the right or left prefrontal cortex (PFC).
• Visual working memory capacity was assessed behaviorally.
• Occipitoparietal contralateral delay activity (CDA) was measured using electroencephalography (EEG) to monitor brain activity during memory retention.

Main Results:

• 1064-nm tPBM applied to the right PFC significantly improved visual working memory capacity.
• This enhancement correlated with an increased CDA set-size effect during the retention phase.
• tPBM at 852 nm or applied to the left PFC did not yield significant improvements in WM or CDA measures.

Conclusions:

• 1064-nm tPBM targeted at the right PFC effectively enhances visual working memory capacity in humans.
• The contralateral delay activity (CDA) serves as a neural correlate mediating the effects of tPBM on WM.
• These findings highlight the specificity of tPBM parameters for cognitive enhancement and provide evidence for its therapeutic potential.