Local Computation of Lightness on Articulated Surrounds

Sawayama, Masataka; Kimura, Eiji

doi:10.1068/i0528

Cited by 3 publications

(2 citation statements)

References 29 publications

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“…normal or corrected-to-normal visual acuity and normal trichromatic color vision and gave written informed consent. The sample size of this study is much larger compared with that of typical lightness perception studies (e.g., Madigan & Brainard, 2014;Sawayama & Kimura, 2012). Stimuli were presented on an LCD screen (NEC MultiSync LCD-PA241W, screen size 518 Â 324 mm, 1920 Â 1200 pixels, refresh frequency 60 Hz, CIE chromaticity coordinates of white: x ¼ 0.322, y ¼ 0.326) by a computer program created with PsychoPy2 1.…”

Section: Introductionmentioning

confidence: 99%

Effects of Lip Color on Perceived Lightness of Human Facial Skin

2017

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Whereas geometric illusions in human faces have been reported by several studies, illusions of color or lightness in faces have seldom been explored. Here, we psychophysically investigated whether lip color influences facial skin's perceived lightness. Results of Experiment 1 demonstrated that redder lips lightened and darker lips darkened the perceived complexion. These lightness or darkness inducing effects differ from the classical illusion of lightness contrast in nonface objects for two reasons. First, illusory effects are more assimilative than contrastive. Second, the inducing area (i.e., lips) is much smaller than the influenced area (facial skin). Experiment 2 showed that the assimilative lightness induction was caused by holistic processing of faces. This is the first study to scientifically substantiate the claim of cosmetics manufacturers and makeup artists that lip colors can alter perceived facial skin color. Implications for face perception, lightness illusion, and perceptual effects of cosmetics are discussed.

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Section: Introductionmentioning

confidence: 99%

Effects of Lip Color on Perceived Lightness of Human Facial Skin

2017

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“…Gilchrist (1980) reported no effect in a pilot replication of Hochberg and Beck with cast and attached shadows present. Other studies (Rutherford & Brainard, 2002;Sawayama & Kimura, 2012) have also shown lightness to be inconsistent with perceived illumination.…”

Section: Verbal Reportsmentioning

confidence: 90%

To compute lightness, illumination is not estimated, it is held constant.

Gilchrist

2018

Journal of Experimental Psychology: Human Perception and Perfor

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The light reaching the eye from a surface does not indicate the black-gray-white shade of a surface (called lightness) because the effects of illumination level are confounded with the reflectance of the surface. Rotating a gray paper relative to a light source alters its luminance (intensity of light reaching the eye) but the lightness of the paper remains relatively constant. Recent publications have argued, as had Helmholtz (1866/1924), that the visual system unconsciously estimates the direction and intensity of the light source. We report experiments in which this theory was pitted against an alternative theory according to which illumination level and surface reflectance are disentangled by comparing only those surfaces that are equally illuminated, in other words, by holding illumination level constant. A 3-dimensional scene was created within which the rotation of a target surface would be expected to become darker gray according to the lighting estimation theory, but lighter gray according to the equi-illumination comparison theory, with results clearly favoring the latter. In a further experiment cues held to indicate light source direction (cast shadows, attached shadows, and glossy highlights) were completely eliminated and yet this had no effect on the results. (PsycINFO Database Record

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Spatial organization affects lightness perception on articulated surrounds

Sawayama

Kimura

2013

Journal of Vision

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The articulation effect refers to a change in lightness contrast induced by adding small patches of different luminances to a uniform background surrounding a target in a lightness contrast display. This study investigated how local luminance signals are integrated to generate the articulation effect. We asked whether spatial organization due to perceptual grouping can influence the articulation effect even when the spatially averaged luminance of the surrounds is held constant. Grouping factors used were common-fate motion (Experiment 1), similarity of orientation (Experiment 2), and synchrony (Experiment 3). Results of all experiments consistently showed that the articulation effect was larger when the target was strongly grouped with the articulation patches. These findings provide converging evidence for the effects of spatial organization on the articulation effect. Moreover, they suggest that lightness computation underlying the articulation effect depends on a middle-level representation in which perceptual organization is at least partially established. The changes in lightness perception due to spatial organization could be accounted for by the double-anchoring theory of lightness (Bressan, 2006b).

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Local Computation of Lightness on Articulated Surrounds

Cited by 3 publications

References 29 publications

Effects of Lip Color on Perceived Lightness of Human Facial Skin

Effects of Lip Color on Perceived Lightness of Human Facial Skin

To compute lightness, illumination is not estimated, it is held constant.

Spatial organization affects lightness perception on articulated surrounds

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