Akash Chaudhary presents High-resolution image reconstruction with latent diffusion models from human brain activity

On 2024-07-04 11:00:00 at https://feectu.zoom.us/j/98555944426
Reconstructing visual experiences from human brain activity offers a unique way
to understand how the brain represents the world, and to interpret the
connection between computer vision models and our visual system. While deep
generative models have recently been employed for this task, reconstructing
realistic images with high semantic fidelity is still a challenging problem.
Here, we propose a new method based on a diffusion model (DM) to reconstruct
images from human brain activity obtained via functional magnetic resonance
imaging (fMRI). More specifically, we rely on a latent diffusion model (LDM)
termed Stable Diffusion. This model reduces the computational cost of DMs, while
preserving their high generative performance. We also characterize the inner
mechanisms of the LDM by studying how its different components (such as the
latent vector of image Z, conditioning inputs C, and different elements of the
denoising U-Net) relate to distinct brain functions. We show that our proposed
method can reconstruct high-resolution images with high fidelity in
straight-forward fashion, without the need for any additional training and
fine-tuning of complex deep-learning models. We also provide a quantitative
interpretation of different LDM components from a neuroscientific perspective.
Overall, our study proposes a promising method for reconstructing images from
human brain activity, and provides a new framework for understanding DMs

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