Assimilative and non-assimilative color spreading in the watercolor configuration

A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e...

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Main Authors: Eiji eKimura, Mikako eKuroki
Format: Article
Language:English
Published: Frontiers Media S.A. 2014-09-01
Series:Frontiers in Human Neuroscience
Subjects:
Online Access:http://journal.frontiersin.org/Journal/10.3389/fnhum.2014.00722/full
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author Eiji eKimura
Mikako eKuroki
author_facet Eiji eKimura
Mikako eKuroki
author_sort Eiji eKimura
collection DOAJ
description A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC) is paired with a blue outer contour (OC), yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and OC luminances (Experiment 1) as well as the background luminance (Experiment 2). The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminances (IC contrast) was smaller than that of the OC (OC contrast), the induced color became similar to the IC color (assimilative spreading). In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading). Extending these findings, Experiment 3 showed that bilateral color spreading, e.g., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading [Grossberg, S. & Mingolla, E. (1985) Percept. Psychophys., 38, 141-171] and extended for the watercolor effect [Pinna, B., & Grossberg, S. (2005) J. Opt. Soc. Am. A, 22, 2207-2221]. However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.
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spelling doaj.art-76fc319794194024804d885b8ffea1bc2022-12-21T18:42:28ZengFrontiers Media S.A.Frontiers in Human Neuroscience1662-51612014-09-01810.3389/fnhum.2014.00722107664Assimilative and non-assimilative color spreading in the watercolor configurationEiji eKimura0Mikako eKuroki1Chiba UniversityChiba UniversityA colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC) is paired with a blue outer contour (OC), yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and OC luminances (Experiment 1) as well as the background luminance (Experiment 2). The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminances (IC contrast) was smaller than that of the OC (OC contrast), the induced color became similar to the IC color (assimilative spreading). In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading). Extending these findings, Experiment 3 showed that bilateral color spreading, e.g., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading [Grossberg, S. & Mingolla, E. (1985) Percept. Psychophys., 38, 141-171] and extended for the watercolor effect [Pinna, B., & Grossberg, S. (2005) J. Opt. Soc. Am. A, 22, 2207-2221]. However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.http://journal.frontiersin.org/Journal/10.3389/fnhum.2014.00722/fullVisual Illusionsassimilationluminance contrastColor spreadingwatercolor effect
spellingShingle Eiji eKimura
Mikako eKuroki
Assimilative and non-assimilative color spreading in the watercolor configuration
Frontiers in Human Neuroscience
Visual Illusions
assimilation
luminance contrast
Color spreading
watercolor effect
title Assimilative and non-assimilative color spreading in the watercolor configuration
title_full Assimilative and non-assimilative color spreading in the watercolor configuration
title_fullStr Assimilative and non-assimilative color spreading in the watercolor configuration
title_full_unstemmed Assimilative and non-assimilative color spreading in the watercolor configuration
title_short Assimilative and non-assimilative color spreading in the watercolor configuration
title_sort assimilative and non assimilative color spreading in the watercolor configuration
topic Visual Illusions
assimilation
luminance contrast
Color spreading
watercolor effect
url http://journal.frontiersin.org/Journal/10.3389/fnhum.2014.00722/full
work_keys_str_mv AT eijiekimura assimilativeandnonassimilativecolorspreadinginthewatercolorconfiguration
AT mikakoekuroki assimilativeandnonassimilativecolorspreadinginthewatercolorconfiguration