Illuminating Cognitive Performance: Assessing the Role of Transcranial Photobiomodulation in Augmenting Cognition

Transcranial photobiomodulation (tPBM) is an innovative, noninvasive neuromodulation modality that utilizes near-infrared light to modulate neural activity and improve cognition.

Participants were assigned to either a tPBM or sham group for 2 sessions. Depending on the group, both sessions consisted of cognitive tasks and brain stimulation (1,070 nm intensity for 15 minutes).

The results highlight the neurophysiological effects of tPBM compared to sham. Eight participants (sham, n = 4; active tPBM, n = 4), primarily female, aged between 18 and 45. N = 3 out of 4 participants who received tPBM stimulation demonstrated a decrease in all 3 dimensions of the Depression, Anxiety, and Stress Scale from T1 to T2. Speed of processing showed a statistically significant difference between tPBM and sham groups for plasticity (P = .013) and reaction time (RT) (P = .038) measures. On an orientation working memory task, analyses revealed a significant difference in K-values for high-load trials between the tPBM and sham group (P = .039). Analyses concluded the sham group showed no significant changes in pupil dilation or RT across sessions. However, the tPBM group exhibited a significant increase in pupil dilation from session 1 to session 2 (P = .015). Moreover, the tPBM group exhibited less variability in pupil dilation (M = 0.86, SD = 0.09) than the sham group (M = 4.26, SD = 1.77) (P < .001).

The present study sought to examine the effects of tPBM on various domains of cognitive performance. Results align with prior studies suggesting tPBM is most effective when neural resources are taxed, reinforcing its potential application in improving cognition. More research, alongside a larger sample size should be done to further investigate the role of tPBM on cognitive performance for medicinal and industrial applications in the military.