Design and validation of EEG biomarkers for transcranial photobiomodulation

Transcranial Photobiomodulation (tPBM) offers significant potential for cognitive enhancement and therapy. A critical gap remains in our understanding of the differential impacts of pulsed versus continuous tPBM on human electroencephalogram (EEG) patterns. Treatment planners do not have objective metrics to ascertain optimal dosage parameters which hampers the development of effective closed-loop neuromodulation systems. This study focuses on key EEG markers: interhemispheric coherence and frequency entrainment. Concurrent tPBM and EEG recordings were conducted on healthy participants in single sessions with continuous, pulsed and modular protocols. Putative indicators of effective tPBM protocols in healthy participants are hypothesized to be significant post-intervention increases in relative alpha frequency power and coherence normalization. The study quantifies changes from baseline to demonstrate tPBM dosimetry effects. We anticipate that our study will elucidate the distinct effects of pulsed versus continuous tPBM protocols, with an expected interhemispheric coherence normalization and frequency entrainment.