The perception of yellow in bruises.
For forensic purposes, the presence of the colour yellow in a bruise may be regarded as indicating it is not recent. However, a previous study has shown that observers may disagree in their description of the colours in a bruise. This study was designed to determine how consistent observers are in perceiving the presence of yellow. Subjects were shown a series of photographs of a bruise that had been digitally modified (Adobe Photoshop) to contain amounts of yellow that increased from 2% to 20%. The point at which subjects first perceived the colour yellow was recorded. The perception threshold for yellow ranged from 4% to 16% (mean=8.7%, median=8%) in the 50 subjects that had normal colour vision. Statistical analysis indicated that an individual's yellow perception threshold increased by 0.07% each year, but gender had no effect. The results reveal that there is variability in the perception threshold for yellow in the general population and that a subject's ability to perceive yellow in a bruise declines with age.
University of Sydney, Sydney, Australia.
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VK
Hughes
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Ellis
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Langlois
D000328:Adult; D000367:Age Factors; D000375:Aging / Q000502:physiology; D003118:Color Perception / Q000502:physiology; D003117:Color Vision Defects / Q000503:physiopathology; D003288:Contusions / Q000473:pathology*; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D014949:Wounds, Nonpenetrating / Q000473:pathology*