Brain-to-Image/Video Decoding
After brain-to-language, the second major frontier is reconstructing the visual scenes a user sees or imagines from neural activity. In 2023–2024, three key advances appeared: MindEye / MindEye2 used diffusion models to decode fMRI signals into high-fidelity images; MinD-Video reconstructed video from fMRI for the first time; and EEG2Video replicated the pipeline on the non-invasive side. At the same time, Fernández 2021 Science Advances let a blind patient see stable phosphenes for the first time via V1 microstimulation — the starting point of visual write-in.
Relationship to Chapter 07. Brain-to-language maps neural signals to discrete symbols; brain-to-vision maps them to a high-dimensional continuous space (pixels / latents). The diffusion-model boom supplies exactly the prior this needs: MindEye projects fMRI embeddings into the CLIP-aligned latent space of Stable Diffusion, so that "any fMRI voxel pattern can be turned into a plausible image with a diffusion prior." This chapter has the most direct tension with Chapter 13 (Ethics) — visual reconstruction can recover a user's private visual memories, and is one of the strongest motivations for neurorights legislation.
Recommended reading order. Start with fMRI Image Reconstruction and master the three trunks: MindEye / MindEye2 / Takagi-Nishimoto Stable Diffusion; then Semantic Reconstruction fills in Tang 2023 Nat Neuro's semantic-level decoding and the CLIP-latent route; Brain-to-Video Decoding extends along the time axis to video (MinD-Video / EEG2Video NeurIPS 2024); and finally, Visual Cortex Prosthesis turns to the write-in side and traces the engineering path toward high-resolution phosphenes after Fernández 2021 — this section is the visual counterpart to the sensory writing in Chapter 09.
Chapter contents:
- fMRI Image Reconstruction — MindEye (ICLR 2023), MindEye2 (ICML 2024), Takagi-Nishimoto Stable Diffusion
- Semantic Reconstruction — Tang 2023 Nat Neuro; MindDiffuser; CLIP latent-space decoding
- Brain-to-Video Decoding — MinD-Video, Kupershmidt self-supervised, EEG2Video NeurIPS 2024
- Visual Cortex Prosthesis — Fernández 2021 Sci Adv; high-resolution phosphene roadmap