Within-Subject Optogenetic Model Reveals Spatiotemporal Cortical Reorganization in Artificial Vision

Visual prostheses can elicit simple percepts such as letter forms through dynamically patterned stimulation, yet naturalistic dynamic vision remains out of reach despite hardware fully capable of high-resolution temporal control. This persistent gap suggests the bottleneck lies in how artificial input is represented by the cortex itself. A fundamental question remains unresolved: when artificial vision bypasses natural retinal encoding, what is lost in cortical representation? We address this question in this paper using a retinal optogenetic mouse model that isolates the consequence of bypassing retinal encoding while preserving downstream pathways. Using within-subject V1 cortex electrophysiology and CNN-based decoding under identical dynamic stimuli, we reveal dissociable, dimension-specific gaps. Temporally, artificial vision bypassed the frequency-dependent compression imposed by natural vision, extending stimulus-locked entrainment bandwidth. Spatially, direction-selective representations underwent systematic remapping, with disrupted phase organization and reduced encoding regularity. These findings show that bypassing natural retinal encoding reorganizes cortical representation along dissociable spatiotemporal dimensions, establishing a within-subject framework that renders such structural divergences easy to locate and quantifiable.