The Perpetual Diamond: Contrast Reversals Along Thin Edges Create the Appearance of Motion in Objects

Flynn, Oliver; Shapiro, Arthur

doi:10.1177/2041669518815708

Cited by 7 publications

(14 citation statements)

References 20 publications

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“…“Movie 1” in Flynn and Shapiro's 2018 open-source publication demonstrates this perpetual motion. 12 The MDS assessment consists of three components: a center diamond, four edges of the diamond, and a surround field. The center diamond has a fixed mid-level luminance; the surround is a circular field with a luminance of two hertz; and the four edges are thin rectangular bars surrounding the diamond that also have a luminance modulating at two hertz.…”

Section: Introductionmentioning

confidence: 99%

“…The direction of the perceived motion of the diamond is dependent on the temporal phase of the edge's modulations relative to the phase of the surround modulation. 12 …”

Section: Introductionmentioning

confidence: 99%

“… 18 However, if the luminance of the edges also changes in time, the motion can be made to shift perpetually in one direction. 12 , 19 , 20 The direction of motion depends on the phase of the edges’ modulations relative to the luminance changes of the shape or surrounding field. The physiological processes underlying the perception are established because the contrast changes produce first-order motion energy in the stimulus.…”

Section: Introductionmentioning

confidence: 99%

“… 21 , 22 Healthy visual systems can perceive this motion with remarkable precision (less than 1 second of visual angle in optimal conditions). 12 …”

Section: Introductionmentioning

confidence: 99%

“…Although a healthy eye should not be affected by contrast modulation ratio changes, impaired visual systems would find these changes difficult. 12 Graphically, the adaptability of the visual contrast system can be represented by the slope of the contrast threshold (dependent variable) plotted against the contrast ratio (independent variable). A slope of zero indicates that contrast ratio changes had no effect on visual performance, whereas a non-zero slope indicates that contrast ratio changes altered visual performance in the MDS assessment.…”

Section: Introductionmentioning

confidence: 99%

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Contrast Sensitivity Testing in Retinal Vein Occlusion Using a Novel Stimulus

Mishra

Maganti

Squires

et al. 2020

Trans. Vis. Sci. Tech.

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Purpose This study evaluated a novel tool known as the motion diamond stimulus (MDS), which utilizes contrast-generated illusory motion in dynamic test regions to determine contrast sensitivity (CS). Methods Patients with treated unilateral retinal vein occlusions (RVOs) underwent three assessments: the MDS, the Pelli-Robson (PR), and the National Eye Institute's Visual Function Questionnaire (VFQ-25). The MDS assessment produced two data end points, α and β. The α value represents the overall contrast threshold level and the β value serves to quantify the adaptability of the visual contrast system. The CS parameters from the MDS and log CS PR output values were used to compare RVO eyes ( n = 20) to control eyes ( n = 20). Results The study participants had a mean composite VFQ-25 score of 89.5 ± 10.4 on the VFQ-25. A significant difference was observed between the RVO eyes and the control eyes in PR log CS scores ( P value = 0.0001) and in MDS α value ( P value = 0.01). No difference in MDS β value was found between the study groups ( P value = 0.39). Conclusions The results for the MDS assessment's α parameter corroborated the PR scores, suggesting contrast sensitivity threshold impairment in patients with RVO. No significant difference in β value was observed, suggesting that adaptability of the visual system is maintained in treated RVO eyes. Translational Relevance Currently, visual complaints cannot be entirely identified by Snellen visual acuity alone. The MDS offers potentially a more complete look at visual function, by including contrast sensitivity and may be able to quantify changes otherwise overlooked in retinal disease progression.

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Section: Introductionmentioning

confidence: 99%

“…The direction of the perceived motion of the diamond is dependent on the temporal phase of the edge's modulations relative to the phase of the surround modulation. 12 …”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“… 21 , 22 Healthy visual systems can perceive this motion with remarkable precision (less than 1 second of visual angle in optimal conditions). 12 …”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Contrast Sensitivity Testing in Retinal Vein Occlusion Using a Novel Stimulus

Mishra

Maganti

Squires

et al. 2020

Trans. Vis. Sci. Tech.

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The Pulfrich Effect in Virtual Reality

Loprete,

Shapiro

2024

Preprint

Self Cite

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The Pulfrich effect, a visual phenomenon where a neural delay in one eye produces a depth misperception, has been directly studied on flat-panel displays but not in virtual reality (VR) environments. Through a series of three experiments, we investigated the relationship between luminance, contrast, dot spacing, and optical blur on the Pulfrich effect in VR and on the perception of motion. In the first two experiments, we found that low-reflectance stimuli produce a stronger Pulfrich effect than high-reflectance stimuli in VR, a result further accentuated by background luminance. Furthermore, the primary experiment showed that nullifying helix rotation motion is a powerful way to study the magnitude of the Pulfrich effect. With data from the first experiment, we developed a compelling VR illusion in which changing the color of a helix reverses the direction of perceived motion. Experiment 2 elaborated that low-reflectance stimuli only produce a stronger Pulfrich effect than high-reflectance stimuli when the stimulus is moving away from the delayed eye. Data from the first two experiments were successfully captured by power law function fits and linearized by plotting Pulfrich effect strength against logit-Michelson contrast. Our third experiment revealed that increasing blur and dot count in the helix stimulus increased the likelihood of perceiving up or down motion. All three experiments in tandem show that investigating well-known visual illusions such as the Pulfrich effect in virtual reality has the potential to reveal insights into visual perception as well as inform us about the effects of contrast and asymmetric lighting in spatial computing.

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Similar extrapolation of moving objects' locations for perception and saccades

Brenner,

Smeets

2024

Journal of Vision

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The Perpetual Diamond: Contrast Reversals Along Thin Edges Create the Appearance of Motion in Objects

Cited by 7 publications

References 20 publications

Contrast Sensitivity Testing in Retinal Vein Occlusion Using a Novel Stimulus

Contrast Sensitivity Testing in Retinal Vein Occlusion Using a Novel Stimulus

The Pulfrich Effect in Virtual Reality

Similar extrapolation of moving objects' locations for perception and saccades

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