5. Conclusion
The study investigated the neural mechanisms of phosphene using
oscillatory transcranial electric stimulations with different polarities
and amplitude modulations. Firstly, our results demonstrated that
oscillatory electric stimulation can elicit phosphene irrespective of
polarity. This finding underscores the importance of dynamic
electromagnetic changes in the emergence of visual experiences,
supporting the global resonance theory’s proposition that brain
oscillation could serve as the foundation of consciousness. Furthermore,
we illustrated that neural alignment to AM frequency contributes to
phosphene flash rate, and this effect is independent of carrier
frequency. This result implies that alignment to external stimulations
significantly influences the subjective perception of temporal
frequency. Finally, the observation of increased brightness with anodal
otDCS and prolonged RT with cathodal otDCS suggests a polarity effect on
phosphene quality without interacting with threshold intensity. This
discovery implies that current oscillation and polarity may be processed
independently, contributing to different aspects of phosphene. In line
with our research objectives, the current study provides substantial
evidence elucidating the underlying mechanisms of phosphene perception.
Our findings in perceptual measurements establish a connection between
neural oscillation and subjective visual experiences, opening up new
possibilities for future research on prosthesis vision techniques.