Cortical Dynamics of Phosphene Perception: A Study Using EEG Signals

The electrical stimulation of the primary occipital cortex can evoke luminous perceptions known as phosphenes, forming the basis for cortical visual prostheses for blind individuals. In this study, cortical dynamics during phosphene perception were investigated in a blind subject implanted with a 10 × 10 Utah microelectrode array in the visual cortex. EEG analyses revealed significant event-related synchronization/desynchronization (ERS/ERD) differences in the 4–7.5 Hz range, primarily in frontal regions, 250–750 ms post-stimulus. Connectivity analysis using the directed transfer function (DTF) showed directional connections from temporal to frontal areas during perception. These findings provide preliminary insights into the cortical dynamics associated with phosphene perception and highlight the potential of EEG for characterizing neural activity in such contexts.