1997
@article{BeS1997,
vgclass = {refpap},
author = {Anthony J. Bell and Terrence J. Sejnowski},
title = {The ``independent components'' of natural scenes are edge
filters},
journal = {Vision Research},
volume = {37},
number = {23},
pages = {3327--3338},
month = {December},
year = {1997},
url = {http://dx.doi.org/10.1016/S0042-6989(97)00121-1},
abstract = {It has previously been suggested that neurons with line
and edge selectivities found in primary visual cortex of cats and
monkeys form a sparse, distributed representation of natural scenes,
and it has been reasoned that such responses should emerge from an
unsupervised learning algorithm that attempts to find a factorial code
of independent visual features. We show here that a new unsupervised
learning algorithm based on information maximization, a nonlinear
"infomax" network, when applied to an ensemble of natural scenes
produces sets of visual filters that are localized and oriented. Some
of these filters are Gabor-like and resemble those produced by the
sparseness-maximization network. In addition, the outputs of these
filters are as independent as possible, since this infomax network
performs Independent Components Analysis or ICA, for sparse
(super-gaussian) component distributions. We compare the resulting ICA
filters and their associated basis functions, with other decorrelating
filters produced by Principal Components Analysis (PCA) and zero-phase
whitening filters (ZCA). The ICA filters have more sparsely distributed
(kurtotic) outputs on natural scenes. They also resemble the receptive
fields of simple cells in visual cortex, which suggests that these
neurons form a natural, information-theoretic coordinate system for
natural images.},
}