Abstract
The processing of texture patterns has been characterized by a model that postulates a first-stage linear filter to highlight a component texture, a pointwise rectification stage to convert contrast for the highlighted texture into mean response strength, followed by a second-stage linear filter to detect the texture-defined pattern. We estimated the spatial-frequency bandwidth of the second-stage filter mediating orientation discrimination of orientation-modulated second-order gratings by measuring threshold elevation in the presence of filtered noise added to the modulation signal. This experiment yielded no evidence for frequency tuning. A second experiment, in which subjects had to detect similar second-order gratings while judging their modulation frequency, produced bandwidth estimates of 1-1.5 octaves, similar to estimated bandwidths of first-order channels. We propose that an additional dominant-response-selection nonlinearity can account for these apparently contradictory results.
Original language | English (US) |
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Pages (from-to) | 58-68 |
Number of pages | 11 |
Journal | Vision research |
Volume | 81 |
DOIs | |
State | Published - Apr 5 2013 |
Keywords
- Second-order vision
- Texture
ASJC Scopus subject areas
- Ophthalmology
- Sensory Systems