&lt;title&gt;Spatial Frequency Analysis Of Three-Dimensional Vision&lt;/title&gt;

Pulliam, Kenneth

doi:10.1117/12.932660

Cited by 16 publications

(14 citation statements)

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“…Above a disparity corrugation spatial frequency of 1 c/d, the optimum carrier spatial frequency is approximately 2.6x the corrugation spatial frequency. These results resolve what at first appeared to be a discrepancy between the results of a number of previous studies [2] , [3] , [4] . The consequence of this finding is that in order to validly compare how disparity sensitivity varies as a function of disparity corrugation, spatial frequency measurements should be done under conditions of comparable, and ideally optimal, conditions.…”

Section: Introductionsupporting

confidence: 80%

Similar Mechanisms Underlie the Detection of Horizontal and Vertical Disparity Corrugations

2014

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Our aim was to compare sensitivity for horizontal and vertical disparity corrugations and to resolve whether these stimuli are processed by similar or radically different underlying mechanisms. We measure global disparity sensitivity as a function of carrier spatial frequency for equi-detectable carriers and found a similar optimal carrier relationship for vertical and horizontal stimuli. Sensitivity as a function of corrugation spatial frequency for stimuli of comparable spatial summation and composed of optimal, equi-detectable narrowband carriers did not significantly differ for vertical and horizontal stimuli. A small anisotropy was revealed when fixed, high contrast broadband carriers were used. In a separate discrimination-at-threshold experiment, multiple mechanisms of similar tuning were revealed to underlie the detection of both vertical and horizontal disparity corrugations. We conclude that the processing of the horizontal and vertical disparity corrugations occurs along similar lines.

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Section: Introductionsupporting

confidence: 80%

Similar Mechanisms Underlie the Detection of Horizontal and Vertical Disparity Corrugations

2014

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“…We constructed a Disparity Sensitivity Function (DSF) from the estimated neural thresholds. To compare the shape of the 'neural DSF' against the DSF measured in a range of psychophysical studies (Figure 5, Panel D: (Tyler, 1973;Schumer and Ganz, 1979;Pulliam, 1982;Rogers and Graham, 1982;Lankheet and Lennie, 1996;Lee and Rogers, 1997;Bradshaw and Rogers, 1999;Hess et al, 1999;Hogervorst et al, 2000;Tyler and Kontsevich, 2001;Bradshaw et al, 2006;Serrano-Pedraza and Read, 2010;Didyk et al, 2011;Kane et al, 2014;Peterzell et al, 2017)), we extracted reported data using WebPlotDigitizer (software freely available at https://automeris.io/WebPlotDigitizer/) and normalized by dividing each threshold against the lowest threshold in each dataset, forcing each DSF to bottom out at 1. Where both upper and lower limits of disparity sensitivity were measured, the upper limit datapoints were excluded.…”

Section: Estimating Neural Thresholdsmentioning

confidence: 99%

Dynamics of absolute and relative disparity processing in human visual cortex

Kaestner

Evans²,

Yd³

et al. 2021

Preprint

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Cortical processing of binocular disparity is believed to begin in V1 where cells are sensitive to absolute disparity, followed by the extraction of relative disparity in higher visual areas. While much is known about the cortical distribution and spatial tuning of disparity-selective neurons, the relationship between their spatial and temporal properties is less well understood. Here, we use steady-state Visual Evoked Potentials and dynamic random dot stereograms to characterize the temporal dynamics of spatial mechanisms in human visual cortex that are primarily sensitive to either absolute or relative disparity. Stereograms alternated between disparate and non-disparate states at 2 Hz. By varying the spatial frequency content of the disparate fields from a planar surface to corrugated ones, we biased responses towards absolute vs. relative disparities. Reliable Components Analysis was used to derive two dominant sources from the 128 channel EEG records. The first component (RC1) was maximal over the occipital pole while the second component (RC2) was maximal over right lateral occipital electrodes. In RC1, first harmonic responses were sustained, tuned for corrugation frequency, and sensitive to the presence of disparity references, consistent with prior psychophysical sensitivity measurements. By contrast, the second harmonic, associated with transient processing, was not spatially tuned and was indifferent to references, consistent with it being generated by an absolute disparity mechanism. In RC2, the sustained response component showed similar tuning and sensitivity to references. However, sensitivity for absolute disparity dropped off, and transient signals were mainly driven by the lowest corrugation frequencies.

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“…Consequently we will experience a greater magnitude and range of relative binocular disparities [4]. It has been proposed that the visual system may process disparity at different disparity spatial scales along separate channels [5], analogous to the channels selective for luminance differences at different luminance spatial frequencies [6]. Using a variety of paradigms to investigate both absolute and relative disparity processing, several authors have provided evidence for at least two [7][8][9][10][11] or more [12] disparity spatial channels for disparity processing, which in turn may rely on distinct sets of luminance spatial channels [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Near-optimal combination of disparity across a log-polar scaled visual field

et al. 2020

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The human visual system is foveated: we can see fine spatial details in central vision, whereas resolution is poor in our peripheral visual field, and this loss of resolution follows an approximately logarithmic decrease. Additionally, our brain organizes visual input in polar coordinates. Therefore, the image projection occurring between retina and primary visual cortex can be mathematically described by the log-polar transform. Here, we test and model how this space-variant visual processing affects how we process binocular disparity, a key component of human depth perception. We observe that the fovea preferentially processes disparities at fine spatial scales, whereas the visual periphery is tuned for coarse spatial scales, in line with the naturally occurring distributions of depths and disparities in the real-world. We further show that the visual system integrates disparity information across the visual field, in a near-optimal fashion. We develop a foveated, log-polar model that mimics the processing of depth information in primary visual cortex and that can process disparity directly in the cortical domain representation. This model takes real images as input and recreates the observed topography of human disparity sensitivity. Our findings support the notion that our foveated, binocular visual system has been moulded by the statistics of our visual environment.

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<title>Spatial Frequency Analysis Of Three-Dimensional Vision</title>

Cited by 16 publications

References 0 publications

Similar Mechanisms Underlie the Detection of Horizontal and Vertical Disparity Corrugations

Similar Mechanisms Underlie the Detection of Horizontal and Vertical Disparity Corrugations

Dynamics of absolute and relative disparity processing in human visual cortex

Near-optimal combination of disparity across a log-polar scaled visual field

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