Contrast discrimination in noise

Legge, Gordon E.; Kersten, Daniel; Burgess, Arthur E.

doi:10.1364/josaa.4.000391

Cited by 269 publications

(230 citation statements)

References 23 publications

Supporting

Mentioning

212

Contrasting

Order By: Relevance

“…This is consistent with the conclusion reached by Legge, Kersten, and Burgess (1987), based on their measurements of contrast discrimination in the presence of externally added visual noise. Legge et aI.…”

Section: Discussionsupporting

confidence: 92%

Contrast-increment thresholds are related to variability in the apparent contrast function

Baro

Lehmkuhle

Applegate

1988

Perception & Psychophysics

View full text Add to dashboard Cite

Although Fechner (1860Fechner ( /1912 asserted that the gain of a sensory system should determine its ability to resolve different stimulus magnitudes, most researchers have found that gain and resolving power are not consistently related. The present study assessed gain (measured by magnitude estimation) and increment threshold (measured by a forced-choice procedure) in the same observers under the same viewing conditions. It was found that gain and increment threshold were not inversely related, as proposed by Fechner. However, relative variability in apparent contrast (standard error/magnitude estimate) was correlated with relative increment threshold (increment thresholdlbackground contrast). This correlation was even higher following pattern adaptation. These findings imply that resolving power for contrast is determined by variability in the system's response to contrast rather than by its gain. Because this relationship is strengthened by adaptation, adaptation may reduce the contribution of other factors that add noise to the unadapted visual system.

show abstract

Section: Discussionsupporting

confidence: 92%

Contrast-increment thresholds are related to variability in the apparent contrast function

Baro

Lehmkuhle

Applegate

1988

Perception & Psychophysics

View full text Add to dashboard Cite

show abstract

“…One way in which psychophysical facilitation can occur is if the mask gently stimulates the detecting mechanism bringing it closer to detection threshold (Legge and Foley, 1980). However, this process is typically associated with a reduction of the slope of the psychometric function (to a Weibull ␤ ϳ1.25) (Pelli, 1985;Legge et al, 1987;Bird et al, 2002;Meese et al, 2006), whereas the psychometric functions here (not shown) were affected only modestly, if at all, by mask contrast and remained steep (typical Weibull ␤ ϳ3 or 4). We have proposed an alternative account of this facilitatory effect elsewhere Meese et al, in press).…”

Section: Experiments Ii: Cross-orientation Contrast Maskingmentioning

confidence: 80%

Psychophysical evidence for two routes to suppression before binocular summation of signals in human vision

2007

View full text Add to dashboard Cite

Abstract-Visual mechanisms in primary visual cortex are suppressed by the superposition of gratings perpendicular to their preferred orientations. A clear picture of this process is needed to (i) inform functional architecture of image-processing models, (ii) identify the pathways available to support binocular rivalry, and (iii) generally advance our understanding of early vision. Here we use monoptic sine-wave gratings and cross-orientation masking (XOM) to reveal two crossoriented suppressive pathways in humans, both of which occur before full binocular summation of signals. One is a within-eye (ipsiocular) pathway that is spatially broadband, immune to contrast adaptation and has a suppressive weight that tends to decrease with stimulus duration. The other pathway operates between the eyes (interocular), is spatially tuned, desensitizes with contrast adaptation and has a suppressive weight that increases with stimulus duration. When cross-oriented masks are presented to both eyes, masking is enhanced or diminished for conditions in which either ipsiocular or interocular pathways dominate masking, respectively. We propose that ipsiocular suppression precedes the influence of interocular suppression and tentatively associate the two effects with the lateral geniculate nucleus (or retina) and the visual cortex respectively. The interocular route is a good candidate for the initial pathway involved in binocular rivalry and predicts that interocular cross-orientation suppression should be found in cortical cells with predominantly ipsiocular drive.

show abstract

“…The signal amplitudes required for the grating to be visible increase with the amount of external noise. Similar to the situation with electronic amplifiers, the transition point of the two regimes reveals the magnitude of the internal noise.The external noise paradigms have been used to analyze human sensitivity and reveal observer characteristics in a wide range of auditory (Ahumada & Lovell, 1971;Bos & Deboer, 1966;Eijkman, Thijssen, & Vendrik, 1966;Hartmann & Pumplin, 1988;Humes & Jesteadt, 1989;Moore, 1975;Osman, 1971;Richards, Heller, & Green, 1991) and visual tasks (Ahumada, 1987;Ahumada & Watson, 1985;Barlow, 1956;Burgess et al, 1981;D'Zmura & Knoblauch, 1998;Gegenfurtner & Kiper, 1992;Geisler, 1989;Hay & Chesters, 1972;Legge et al, 1987;Nagaraja, 1964;Pelli, 1981Pelli, , 1990Rose, 1948;Tanner & Birdsall, 1958;Tjan, Braje, Legge, & Kersten, 1995;Van Meeteren & Barlow, 1981). One important discovery is that many observer characteristics are invariant across different perceptual tasks within a modality (Pelli & Farell, 1999).…”

mentioning

confidence: 99%

Characterizing observers using external noise and observer models: Assessing internal representations with external noise.

Lü¹,

Dosher²

2008

Psychological Review

224

347

View full text Add to dashboard Cite

External noise methods and observer models have been widely used to characterize the intrinsic perceptual limitations of human observers and changes of the perceptual limitations associated with cognitive, developmental, and disease processes by highlighting the variance of internal representations. The authors conducted a comprehensive review of the 5 most prominent observer models through the development of a common formalism. They derived new predictions of the models for a common set of behavioral tests that were compared with the data in the literature and a new experiment. The comparison between the model predictions and the empirical data resulted in very strong constraints on the observer models. The perceptual template model provided the best account of all the empirical data in the visual domain. The choice of the observer model has significant implications for the interpretation of data from other external noise paradigms, as well as studies using external noise to assay changes of perceptual limitations associated with observer states. The empirical and theoretical development suggests possible parallel developments in other sensory modalities and studies of high-level cognitive processes.Keywords: signal detection theory, internal representation, observer model, perceptual template, internal noise Human decisions are based on internal representations of information. Understanding how stimuli are represented internally is one of the classic problems in psychology. This article examines how modifying an external stimulus with external noise can provide insight into how the stimulus is processed by the human observer. We conducted a systematic and comprehensive review of the external noise paradigms and observer models widely used in characterizing the internal response properties of human observers. The observer approach builds on the broadly applicable framework of signal detection theory (SDT) by elaborating the relationships between external stimuli and the internal response distributions that form the basis for decision. The empirical tests introduce external noise-either masking noise or variation in the relevant stimulus dimension-to provide a reference for characterizing and quantifying the limiting factors in perceptual sensitivity. The current review, analysis, and empirical test focus on visual perception. Some of the model properties, especially the empirical findings, may be modality specific. Still, this framework and the findings could serve as an example for parallel development of the empirical methods and theoretical models in other sensory modalities. The model development and testing also have major implications for applications of the external noise paradigms in understanding the mechanisms underlying changes of perceptual sensitivity in different cognitive, disease, and/or developmental states. Internal Response DistributionsSDT provides a general framework for analyzing human decision making in perceptual and cognitive tasks (Green & Swets, 1966;Macmillan & Creelman, 1991). In a ...

show abstract

Contrast discrimination in noise

Cited by 269 publications

References 23 publications

Contrast-increment thresholds are related to variability in the apparent contrast function

Contrast-increment thresholds are related to variability in the apparent contrast function

Psychophysical evidence for two routes to suppression before binocular summation of signals in human vision

Characterizing observers using external noise and observer models: Assessing internal representations with external noise.

Contact Info

Product

Resources

About