Self-Supervised Natural Image Reconstruction and Rich Semantic Classification from Brain Activity

Abstract

AbstractReconstructing natural images and decoding their semantic category from fMRI brain recordings is challenging. Acquiring sufficient pairs (image, fMRI) that span the huge space of natural images is prohibitive. We present a novel self-supervised approach for fMRI-to-image reconstruction and classification that goes well beyond the scarce paired data. By imposing cycle consistency, we train our image reconstruction deep neural network on many “unpaired” data: a plethora of natural images without fMRI recordings (from many novel categories), and fMRI recordings without images. Combining high-level perceptual objectives with self-supervision on unpaired data results in a leap improvement over top existing methods, achieving: (i) Unprecedented image-reconstruction from fMRI of never-before-seen images (evaluated by image metrics and human testing); (ii) Large-scale semantic classification (1000 diverse classes) of categories that are never-before-seen during network training. Such large-scale (1000-way) semantic classification capabilities from fMRI recordings have never been demonstrated before. Finally, we provide evidence for the biological plausibility of our learned model. 1