Contrast detection and direction discrimination of drifting gratings

Green, Marc

doi:10.1016/0042-6989(83)90117-7

Cited by 37 publications

(10 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The speed of drift (0.35 deg/sec) was selected to be representative of the modest speeds in many points of the 3D shape displays, where peak speeds may range up to 2.5 degfsec. Based on data from direction of motion discrimination in near-threshold sine wave stimuli (Ball & Sekuler, 1979;Burr & Ross, 1982;Green, 1983;Watson, Thompson, Murphy, & Nachmias, 1980) and theoretical computations on direction of motion discrimination for random dot stimuli (Nakayama, 1985;van Doom & Koenderink, 1982), we picked the weakest motion stimulus that could be derived from the 3D shape task: the slowest reasonable speed and approximately the same number of dots in the displays to be comparable. That the direction of Discrimination is shown as a function of the intensity increment (as a percent of the "standard" intensity increment), of the stimulus dots on a gray background.…”

Section: Direction-o~~motio~ ~Iscrimi~~tio~ (Experiments 5)mentioning

confidence: 99%

Kinetic depth effect and optic flow—I. 3D shape from Fourier motion

1989

View full text Add to dashboard Cite

Abstract-Fifty-three different 3D shapes were defined by sequences of 2D views (frames) of dots on a rotating 3D surface. (1) Subjects' accuracy of shape identifications dropped from over 90% to less than 10% when either the polarity of the stimulus dots was alternated from light-on-gray to dark-on-gray on successive frames or when neutral gray interframe intervals were interposed. Roth manipulations interfere with motion extraction by spatio-temporal (Fourier) and gradient first-order detectors. Second-order (non-Fourier) detectors that use full-wave rectification are unaffected by alternating-polarity but disrupted by interposed gray frames. (2) To equate the accuracy of two-alternative forced-choice (ZAFC) planar dir~tion-of-motion ~~ri~nation in standard and zloty-alternated stimuli, standard contrast was reduced. 3D shape discrimination survived contrast reduction in standard stimuli whereas it failed completely with polarity-alternation even at full contrast. (3) When individual dots were permitted to remain in the image sequence for only two frames, performance showed little loss compared to standard displays where individual dots had an expected lifetime of 20 frames, showing that 3D shape identification does not require continuity of stimulus tokens. (4) Performance in all discrimination tasks is predicted (up to a monotone transformation) by considering the quality of first-order information (as given by a simple computation on Fourier power) and the number of locations at which motion information is required. Perceptual first-order analysis of optic flow is the primary substrate for st~cture-from-motion computations in random dot displays because only it offers suBicient quality of perceptual motion at a sufficient number of locations.

show abstract

Section: Direction-o~~motio~ ~Iscrimi~~tio~ (Experiments 5)mentioning

confidence: 99%

Kinetic depth effect and optic flow—I. 3D shape from Fourier motion

1989

View full text Add to dashboard Cite

show abstract

“…When gratings are moved at a higher temporal rate, it is possible to see motion at absolute thresholds for increasingly fine gratings (Green, 1983a(Green, , 1983bLennie, 1980b;Watson, Thompson, Murphy, & Nachmias, 1980). Therefore, the transient system should mediate detection at increasing spatial frequencies when faster temporal rates are employed.…”

Section: Motion Aftereffects In Uniform Flickermentioning

confidence: 99%

“…(D) Observer detects drifting gratings masked by sinusoidal or noise flicker (Green, 1983c). (E) Observer detects drifting gratings masked by either 3-or 12-deg-wide bars (Green, 1983a). (F) Duration of motion aftereffect seen in uniform flicker following adaptation to gratings of various spatial frequencies (Green, Chilcoat, & Strom eyer , 1983).…”

Section: Adaptation To Flickermentioning

confidence: 99%

See 1 more Smart Citation

Masking by light and the sustained-transient dichotomy

Green

1984

Perception & Psychophysics

Self Cite

View full text Add to dashboard Cite

An interpretation of masking by light in terms of the sustained-transient dichotomy is presented. It is proposed that presentation of a uniform flash has two effects: a masking effect, which occurs within the transient system, and a facilitation effect due to increased adaptation level. These two components have been separated by the employment of uniform flashes (flicker around a mean luminance) that do not change adaptation level. Results of such studies generally suggest that masking by light occurs only when targets are detected by the transient system. However, not all results are consistent with the sustained-transient model. Reexamination of other recent literature reveals that the motion/pattern dichotomy underlying the model is not tenable. Moreover, other evidence appears to refute the view that the sustained system dominates fovea vision while the transient system is more responsive in the periphery. I suggest a modified version of the dichotomy and propose a simple receptive field model of sustained and transient mechanisms.This article is written with three goals in mind. The first is to propose a new interpretation, based on the sustained-transient model, of the masking-by-light phenomenon. The second is to reexamine the validity of the sustained-transient dichotomy and the criteria on which the dichotomy is based. And the third is to present a receptive field model which seems to account for most of the differences between sustained and transient mechanisms.The sustained-transient model (Breitmeyer & Ganz, 1976;Keesey, 1972;Kulikowski & Tolhurst, 1973;Tolhurst, 1973) has become one of the most influential theories in vision. It has been used to explain a number of phenomena, including metacontrast masking (Breitmeyer & Ganz, 1976) and pattern masking (Legge, 1978;Pantle, 1983). In this paper, I will attempt to show that the model can be used to largely explain masking by light. Most of the evidence for my interpretation comes from the studies I have conducted, although I will also include converging evidence from other sources.My analysis derives largely from studies in which observers view sinusoidal gratings in the presence of uniform flicker. Data generated by this paradigm were generally consistent with an explanation of masking based on the sustained-transient dichotomy.As the studies progressed, however, it became clear that not all of the results could be reconciled with the most common versions of the sustained-transient model. Moreover, a review of other data published

show abstract

“…Using a motion (MOT)/detection (DET) paradigm, previously used in adults (e.g., Watson, Thompson, Murphy, & Nachmias, 1980;Green, 1983;Graham, 1989), Dobkins and Teller (1996) contrasted thresholds for the detection of a moving stimulus and compared them with those obtained using a discrimination task for the same stimulus in both adult and infant (3 months old) groups. They argue that using this approach allows for the assessment of direction discrimination while controlling for stimulus detectability (see Dobkins and Teller, 1996, for methodological details).…”

Section: Introductionmentioning

confidence: 99%

Using detection or identification paradigms when assessing visual development: Is a shift in paradigm necessary?

et al. 2012

View full text Add to dashboard Cite

Given the inherent difference in judgment required to complete visual detection and identification tasks, it is unknown whether task selection differentially affects visual performance as a function of development. The aim of the present study is therefore to systematically assess and contrast visual performance using these two types of paradigms in order to determine whether paradigm-contingent differences in performance exist across different periods of development. To do so, we assessed sensitivity to both luminance-and texture-defined stationary and dynamic gratings using both detection and identification paradigms. Results demonstrated a relatively unchanged pattern of performance from the school ages through adolescence, suggesting that sensitivity was not differentially affected by choice of paradigm as a function of development. However, when averaged across age groups, a paradigm-contingent difference in sensitivity was evidenced for dynamic, texture-defined gratings only; it was easier to detect the spatial location of the gratings compared with identifying the direction of their motion. Paradigm-contingent differences were not evidenced for luminance-defined stimuli (whether stationary or dynamic), or for stationary, texture-defined gratings. In general, visual performance measured using either detection or identification paradigms is comparable across ages, particularly when information is stationary and defined by more simple visual attributes, such as luminance. Therefore, the use of detection paradigms might be advantageous under most circumstances when assessing visual abilities of very young and/or clinical populations in order to minimize potential challenges not related to visual perception (i.e., attentional) in these populations. Finally, paradigm-contingent differences in performance specific to dynamic, texture-defined information will be discussed.

show abstract

Contrast detection and direction discrimination of drifting gratings

Cited by 37 publications

References 36 publications

Kinetic depth effect and optic flow—I. 3D shape from Fourier motion

Kinetic depth effect and optic flow—I. 3D shape from Fourier motion

Masking by light and the sustained-transient dichotomy

Using detection or identification paradigms when assessing visual development: Is a shift in paradigm necessary?

Contact Info

Product

Resources

About