Visual acuity and signal color pattern in anAnolislizard

Leo J. Fleishman; Anna I. Yeo; Carley W. Perez

doi:10.1242/jeb.150458

High Visibility Conditions in a Sunset Environment

Applied Sciences ◽

10.3390/app11167229 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7229

Author(s):

Tatsuya Iizuka ◽

Takushi Kawamorita ◽

Choku Takenaka ◽

Hajime Tsuji ◽

Hiroyuki Kanai ◽

...

Keyword(s):

Visual Acuity ◽

Spatial Frequency ◽

Visual Target ◽

Color Pattern ◽

Refractive Errors ◽

Stripe Pattern ◽

Spatial Frequencies ◽

Set Up ◽

Healthy Participants ◽

Dark Room

There is no standard for high-visibility safety clothing for general pedestrians, nor is it widely used. Therefore, this study investigated visibility in order to examine the standards for high-visibility safety clothing for general pedestrians. Methods: Twenty healthy participants (mean age, 22.4 ± 4.4 years) without ocular disease, except for refractive errors, were studied. All participants had healthy visual acuity in corrected vision. This study assumed sunset conditions in Japan. The light source was set up in a dark room, and the illuminance in front of the visual target was set to 300 lx. We investigated the visibility of 142 patterns of black and yellow combination samples with different spatial frequencies, pattern types, angles, and color ratios. Results: The highest visibility was found at 5.0 cycles per degree of the stripe pattern at the spatial frequency, yellow ratio of 75%, and a stripe angle of 165°. Conclusions: Under sunset conditions, the brightness decreased when black was combined with yellow. However, it forms a two-color pattern and becomes more conspicuous. The highest visibility was obtained by arranging black and yellow in a diagonal stripe pattern. We predict that establishing clothing standards based on the results of this study will help design safety clothing with increased visibility.

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High Visibility Conditions in a Sunset Environment

10.21203/rs.3.rs-445732/v1 ◽

2021 ◽

Author(s):

Tatsuya Iizuka ◽

Takushi Kawamorita ◽

Choku Takenaka ◽

Hajime Tsuji ◽

Hiroyuki Kanai ◽

...

Keyword(s):

Visual Acuity ◽

Spatial Frequency ◽

Visual Target ◽

Color Pattern ◽

Refractive Errors ◽

Stripe Pattern ◽

Normal Visual Acuity ◽

Spatial Frequencies ◽

Set Up ◽

Dark Room

Abstract Purpose: There is no standard for high-visibility safety clothing for general pedestrians, nor is it widely used. Therefore, this study investigated visibility in order to examine the standards for high-visibility safety clothing for general pedestrians. Methods: Twenty normal participants (mean age, 22.4 ± 4.4 years) without ocular disease, except for refractive errors, were studied. All participants had normal visual acuity in corrected vision. This study assumed sunset conditions in Japan. The light source was set up in a dark room, and the illuminance in front of the visual target was set to 300 lx. We investigated the visibility of 142 patterns of black and yellow combination samples with different spatial frequencies, pattern types, angles, and color ratios. Results: The highest visibility was found at 5.0 cycles per degree of the stripe pattern at the spatial frequency, yellow ratio of 75%, and a stripe angle of 165°. Conclusions: Under sunset conditions, the brightness decreased when black was combined with yellow. However, it forms a two-color pattern and becomes more conspicuous. The highest visibility was obtained by arranging black and yellow in a diagonal stripe pattern. We predict that establishing clothing standards based on the results of this study will help design safety clothing with increased visibility.

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Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

Journal of Paleontology ◽

10.1017/s0022336000058911 ◽

1988 ◽

Vol 62 (01) ◽

pp. 83-87 ◽

Cited By ~ 4

Author(s):

Patricia H. Kelley ◽

Charles T. Swann

Keyword(s):

Functional Morphology ◽

Functional Significance ◽

Intraspecific Variability ◽

Color Pattern ◽

Color Patterns ◽

Historical Factors ◽

Life Mode ◽

Molluscan Fauna ◽

Excellent Preservation ◽

Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

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