V1 Receptive Fields Reflect the Statistical Structure of Natural Scenes
The strategy by which the visual system encodes our environment has long been a topic of debate. One compelling hypothesis is that the tuning characteristics of cells in the visual system provide a sparse representation of natural scenes (Barlow, 1972; Field, 1994). While recent work by Olshausen and Field (1996) supports this hypothesis, other studies suggest alternate explanations (Law and Cooper, 1994; Fyfe and Baddeley, 1995). To address this question, we employ exploratory projection pursuit to investigate the statistical structure of natural scenes—the images the visual system evolved to represent.
Applying projection pursuit to over 130,000 natural image patches, we find that searching for sparse and other non-normal structure results in oriented, band-pass, localized projections. Our results suggest that V1 simple cell receptive fields directly reflect the statistical structure in natural scenes, consistent with Field’s hypothesis (Field, 1994). We relate our technique to that of Olshausen and Field (1996), as well as compare our results to those of similar efforts (Law and Cooper, 1994; Fyfe and Baddeley, I995). In addition, we demostrate how projection pursuit can be used to investigate non-linear processing found in the visual system, such as on-off channel segregation and receptive fields derived from feed-forward projections.
KeywordsReceptive Field Natural Image Image Patch Natural Scene Tight Frame
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- Atick JJ and Li Z (1992) Towards a theory of the striate cortex. Neural Comput. 6, 127–146.Google Scholar
- Atick.Ii and Redlich AN (1992) What does the retina know about natural scenes? Neu,: Comput. 4, 196–210.Google Scholar
- Field DJ (1994) What is the goal of sensory coding? Neu,: Comput. 6, 559–601.Google Scholar
- Press WH, Teukolsky SA, Vetterling WT, and Flannery BP (1992) Minimization or maximization of functions. Numerical recipes in C, 2nd ed, Cambridge University Press.Google Scholar