The spatial receptive elds of simple cells in mammalian striate cortex have been reasonably
well described physiologically 1, 2, 3, 4] and can be characterized as being localized,
oriented, and bandpass (selective to structure at di erent spatial scales), comparable to the
basis functions of wavelet transforms 5, 6]. One approach to understanding such response
properties of visual neurons has been to consider their relationship to the statistical structure
of natural images in terms of e cient coding 7, 8, 9, 10, 11, 12]. Along these lines, a number�…

THE receptive fields of simple cells in mammalian primary visual cortex can be
characterized as being spatially localized, oriented1–4 and bandpass (selective to structure
at different spatial scales), comparable to the basis functions of wavelet transforms5, 6. One
approach to understanding such response properties of visual neurons has been to
consider their relationship to the statistical structure of natural images in terms of efficient
coding7–12. Along these lines, a number of studies have attempted to train unsupervised�…