SourceBeyond single neurons: population response geometry in digital twins of mouse visual cortex
The paper tests ViV1T, a transformer-based digital twin from the Dynamic Sensorium Competition, by simulating the Stringer et al. (2019) V1 population geometry experiment. Despite achieving improved single-neuron prediction accuracy (corr-to-average 0.478 on Sensorium), ViV1T's population response eigenspectrum decays too slowly to be differentiable, matching the failure pattern observed in CNN-based digital twins. The non-differentiability is confirmed across multiple stimulus types (natural images, whitened, spatially localized, gratings), indicating the limitation is not architecture-specific.