Texture-modulation channels for spatial frequency and orientation
نویسندگان
چکیده
منابع مشابه
Modulation frequency and orientation tuning of second-order texture mechanisms.
Modulation frequency and orientation tuning of second-order mechanisms underlying the detection of modulation in local spatial-frequency information are assessed by using an oblique-masking paradigm. Stimuli were Gabor-filtered noise patterns in which the local carrier spatial frequency was modulated about an average value of 4.7 cycles per degree (cpd) according to sinusoidal function. Thresho...
متن کاملSecond-order spatial frequency and orientation channels in human vision
We compared the number of spatial frequency and orientation mechanisms underlying first- versus second-order processing by measuring discrimination at detection threshold for first- and second-order Gabors to determine the smallest difference in spatial frequency and orientation that permits accurate discrimination at threshold. For second-order gratings, the number of channels is the same as f...
متن کاملInteractions among spatial frequency and orientation channels adapted concurrently.
Interactions between size and orientation-specific mechanisms in the human visual system were investigated using a sequential adaptation technique. Subjects adapted to a vertical, 4 c/deg high-contrast (0.7) sinewave grating that was interleaved at a rate of 0.5 Hz with another adapting grating differing either in (1) spatial frequency or (2) orientation. Before and after adaptation contrast th...
متن کاملOrientation- and frequency-modulated textures at low depths of modulation are processed by off-orientation and off-frequency texture mechanisms
Intuitively it may seem likely that orientation-modulated (OM) and frequency-modulated (FM) textures are processed utilizing the first-order channels that are most responsive to the first-order (luminance) information contained in the textures. This assumption would imply that the detection or segmentation of OM or FM textures is accomplished by second-order mechanisms that receive their first-...
متن کاملSpatial frequency discrimination and detection characteristics for gratings defined by orientation texture
We describe evidence consistent with the proposal that the visual system contains a parallel array of size-tuned mechanisms sensitive to orientation texture-defined (OTD) form, and propose that the relative activity of these mechanisms determines spatial frequency discrimination threshold for OTD gratings. Using a pattern of short lines we measured spatial frequency discrimination thresholds fo...
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ژورنال
عنوان ژورنال: Journal of Vision
سال: 2012
ISSN: 1534-7362
DOI: 10.1167/12.9.888