Evidence for spatial frequency and orientation labelled detectors in second-order visual processing
نویسندگان
چکیده
منابع مشابه
Second-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 کاملProperties of second-order spatial frequency channels
The segregation of texture patterns may be carried out by a set of linear spatial filters (to enhance one of the constituent textures), a nonlinearity (to convert the higher contrast of response to that constituent to a higher mean response), and finally subsequent ("second-order") linear spatial filters (to provide a strong response to the texture-defined edge itself). In this paper, the prope...
متن کاملRepresentation of spatial frequency and orientation in the visual cortex.
Knowledge of the response of the primary visual cortex to the various spatial frequencies and orientations in the visual scene should help us understand the principles by which the brain recognizes patterns. Current information about the cortical layout of spatial frequency response is still incomplete because of difficulties in recording and interpreting adequate data. Here, we report results ...
متن کاملModulation 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 کاملHuman primary visual cortex (V1) is selective for second-order spatial frequency.
A variety of cues can differentiate objects from their surrounds. These include "first-order" cues such as luminance modulations and "second-order" cues involving modulations of orientation and contrast. Human sensitivity to first-order modulations is well described by a computational model involving spatially localized filters that are selective for orientation and spatial frequency (SF). It i...
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ژورنال
عنوان ژورنال: Journal of Vision
سال: 2004
ISSN: 1534-7362
DOI: 10.1167/4.8.546