Emergence of Shape Bias in Convolutional Neural Networks through
  Activation Sparsity
Tianqin Li Ziqi Wen Yangfan Li Tai Sing Lee
Current deep-learning models for object recognition are known to be heavily
biased toward texture. In contrast, human visual systems are known to be biased
toward shape and structure. What could be the design principles in human visual
systems that led to this difference? How could we introduce more shape bias
into the deep learning models? In this paper, we report that sparse coding, a
ubiquitous principle in the brain, can in itself introduce shape bias into the
network. We found that enforcing the sparse coding constraint using a
non-differential Top-K operation can lead to the emergence of structural
encoding in neurons in convolutional neural networks, resulting in a smooth
decomposition of objects into parts and subparts and endowing the networks with
shape bias. We demonstrated this emergence of shape bias and its functional
benefits for different network structures with various datasets. For object
recognition convolutional neural networks, the shape bias leads to greater
robustness against style and pattern change distraction. For the image
synthesis generative adversary networks, the emerged shape bias leads to more
coherent and decomposable structures in the synthesized images. Ablation
studies suggest that sparse codes tend to encode structures, whereas the more
distributed codes tend to favor texture. Our code is host at the github
repository: \url{https://github.com/Crazy-Jack/nips2023_shape_vs_texture}