Light-based 40 Hz sensory therapy for brain disorders: physiological basis, therapeutic mechanisms, and future prospects

In recent years, 40 Hz flickering light and/or sound therapy has been confirmed to have certain therapeutic effects on Alzheimer’s disease (AD), although the underlying mechanisms remain unclear. This approach has been widely explored for the treatment of various neurological disorders, but its efficacy must be verified. The induction of gamma oscillations in the brain by 40 Hz flickering light and/or sound stimulation is likely a critical component underlying its therapeutic effects across brain diseases. Elucidating the physiological basis and mechanisms by which such stimuli induce gamma oscillations may reveal its mechanisms of action in treating diseases. Although 40 Hz flickering light and/or sound intervention offers certain advantages in improving neurological function, challenges related to technical optimization and clinical promotion must be addressed. Therefore, in this paper, the underlying mechanisms through which 40 Hz flickering light and/or sound intervention induces gamma oscillations, including both neuronal and non-neuronal mechanisms, are explained. The clinical therapeutic outcomes of 40 Hz flickering light and/or sound intervention for various neurodegenerative diseases are subsequently examined, and the mechanisms underlying are summarized. Furthermore, the limitations of this therapy and corresponding improvement measures are discussed, providing a theoretical reference for further refining this technology and expanding its clinical applications. Finally, future development directions are provided, with the aims of advancing related research and facilitating the application of this therapy in the treatment of brain diseases.