Before revision:  However, a simpler generative model (based on Gaussian-kernel-density estimation) also performed better than each of the discriminative models . None of the candidate models fully explained the human responses.
After revision:  However, a simpler generative model (based on Gaussian-kernel-density estimation) also performed better than purely discriminative DNNs, which learn only to map images to labels . None of the candidate models fully explained the human responses.