Painfree and accurate Bayesian estimation of psychometric functions for (potentially) overdispersed data

Schütt, Heiko H.; Harmeling, Stefan; Macke, Jakob H.; Wichmann, Felix A.

doi:10.1016/j.visres.2016.02.002

Cited by 329 publications

(298 citation statements)

References 42 publications

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“…2 for illustration). 31 The guess rate was fixed to the 50% chance level performance for a 2AFC task and the lapse rate was allowed to vary between 0% and 10%. The reaction times were analyzed in relation to the chronometric response functions obtained in children with NV.…”

Section: Discussionmentioning

confidence: 99%

Symbol Discrimination Speed in Children With Visual Impairments

Barsingerhorn

Boonstra

Goossens

2018

Invest. Ophthalmol. Vis. Sci.

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Citation: Barsingerhorn AD, Boonstra FN, Goossens J. Symbol discrimination speed in children with visual impairments. Invest Ophthalmol Vis Sci. 2018;59:3963-3972. https://doi.org/ 10.1167/iovs.17-23167 PURPOSE. We measured visual acuity and visual discrimination speed simultaneously in children with visual impairments to determine whether they are slower than children with normal vision.METHODS. Five-to twelve-year-old children with visual impairments due to ocular dysfunction (VI o ; n ¼ 30) or cerebral visual impairment (CVI; n ¼ 17) performed a speed-acuity test in which they indicated the orientation of Landolt-C symbols as quickly and accurately as possible. The reaction times for symbols ranging between À0.3 and 1.2 logMAR relative to acuity threshold were compared with normative data. To test whether children were already slow in merely detecting symbols, we also compared their reaction times on a simple visual detection task (VDT) to normative data. An auditory detection task (ADT) was used to probe for other, more general deficits. RESULTS.Of the children with visual impairments, 88% had abnormally long reaction times in the speed-acuity test. This deficit was partly explained by their reduced acuity, but 40% still needed more time to discriminate acuity-matched optotypes. Children responded late in the VDT too, especially those with CVI, but this impairment could not fully account for their slow symbol discrimination. In children with CVI, reaction times in the ADT were affected as much as those in the VDT, suggesting more general sensorimotor problems in CVI.CONCLUSIONS. The speed-acuity test offers additional insight in visual impairment. Children with VI o and CVI are abnormally slow in discerning foveal details. Magnification of materials is often insufficient to compensate for this deficit, partly because stimulus detection is already hampered.

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Section: Discussionmentioning

confidence: 99%

Symbol Discrimination Speed in Children With Visual Impairments

Barsingerhorn

Boonstra

Goossens

2018

Invest. Ophthalmol. Vis. Sci.

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“…The percentage of leftward skew responses as a function of skew amplitude of test stimuli was then fitted with a cumulative Gaussian using Psignifit 4.0 software (asymptotes set free but assumed to be equal) (Schutt et al, 2016). The point of subjective equality (PSE), i.e., the skew amplitude at 50 percent of leftward responses indicated the skew amplitude that was perceived as undistorted.…”

Section: Methodsmentioning

confidence: 99%

Adaptation to Skew Distortions of Natural Scenes and Retinal Specificity of Its Aftereffects

Habtegiorgis

Rifai

Lappe³

et al. 2017

Front. Psychol.

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Image skew is one of the prominent distortions that exist in optical elements, such as in spectacle lenses. The present study evaluates adaptation to image skew in dynamic natural images. Moreover, the cortical levels involved in skew coding were probed using retinal specificity of skew adaptation aftereffects. Left and right skewed natural image sequences were shown to observers as adapting stimuli. The point of subjective equality (PSE), i.e., the skew amplitude in simple geometrical patterns that is perceived to be unskewed, was used to quantify the aftereffect of each adapting skew direction. The PSE, in a two-alternative forced choice paradigm, shifted toward the adapting skew direction. Moreover, significant adaptation aftereffects were obtained not only at adapted, but also at non-adapted retinal locations during fixation. Skew adaptation information was transferred partially to non-adapted retinal locations. Thus, adaptation to skewed natural scenes induces coordinated plasticity in lower and higher cortical areas of the visual pathway.

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“…We then fit the data for each psychometric function separately using a Weibull function in July 22, 2019 the radius increment detection experiment and a logistic function in the rotation discrimination experiment (both parametrized as in [50]). Psychometric functions were determined using Bayesian inference, which tends to give slightly better confidence intervals [51], by directly integrating the posterior [52]. Thresholds were defined as the point at which the psychometric function reached 75% correct performance.…”

Section: Psychophysicsmentioning

confidence: 99%

Contrast invariant tuning in human perception of image content

Fruend

Patel

Stalker

2019

Preprint

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Higher levels of visual processing are progressively more invariant to low-level visual factors such as contrast. Although this invariance trend has been well documented for simple stimuli like gratings and lines, it is difficult to characterize such invariances in images with naturalistic complexity. Here, we use a generative image model based on a hierarchy of learned visual features-a Generative Adversarial Networkto constrain image manipulations to remain within the vicinity of the manifold of natural images. This allows us to quantitatively characterize visual discrimination behaviour for naturalistically complex, non-linear image manipulations. We find that human tuning to such manipulations has a factorial structure. The first factor governs image contrast with discrimination thresholds following a power law with an exponent between 0.5 and 0.6, similar to contrast discrimination performance for simpler stimuli. A second factor governs image content with approximately constant discrimination thresholds throughout the range of images studied. These results support the idea that human perception factors out image contrast relatively early on, allowing later stages of processing to extract higher level image features in a stable and robust way.

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Painfree and accurate Bayesian estimation of psychometric functions for (potentially) overdispersed data

Cited by 329 publications

References 42 publications

Symbol Discrimination Speed in Children With Visual Impairments

Symbol Discrimination Speed in Children With Visual Impairments

Adaptation to Skew Distortions of Natural Scenes and Retinal Specificity of Its Aftereffects

Contrast invariant tuning in human perception of image content

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