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Color Perception (color + perception)
Selected AbstractsRetail Store Lighting for Elderly Consumers: An Experimental ApproachFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 4 2007Nam-Kyu Park The study presents an investigation of the influence of the color of light on readability by figure to background value contrast, color perception, and overall room-light estimation for elderly consumers in an experimental setting representing a retail store. A factorial design with repeated measures was used to identify the impact of three independent variables: (a) lamp color temperatures, (b) lamp color-rendering properties, and (c) age of the participants. The results show that older adults perceived the higher color temperature light source as less cool than did younger adults. Older adults rated their level of comfort and preference higher than the younger participants under all lighting conditions. Regarding readability, higher color-rendering light sources provide better readability, and older adults have more difficulty with warmer lighting when value contrasts were reduced. Implications from this study can be applied to retail lighting techniques to attract elderly consumers. [source] Protection from phototoxic injury during surgery and endoscopy in erythropoietic protoporphyriaLIVER TRANSPLANTATION, Issue 9 2008Staffan Wahlin Erythropoietic protoporphyria is an inherited condition characterized by pronounced solar photosensitivity and in a minority of patients severe liver disease that necessitates liver transplantation for survival. Phototoxic injury to abdominal organs and skin has been reported in several cases of liver transplantation surgery, including a few transplants in which protective light filters were used. This study discusses the optimal characteristics of light filters used during liver transplantation surgery. An experimental model is used to evaluate the relative protection of different filters, and the results are compared with theoretical calculations regarding the risk for phototoxic injury from light sources in health-care procedures. Whether protective measures are warranted in other illuminated procedures besides liver transplantation has been discussed often but never studied. This study elucidates the risk for phototoxic injury in endoscopy, laparoscopy, and non,liver transplant surgery. A theoretical model and epidemiological data are considered. Our findings indicate that endoscopy, laparoscopy, and surgical procedures other than liver transplantation are safe in the noncholestatic protoporphyria patient and that general recommendations for using filters in these situations are not warranted. Among the tested filters, a flexible yellow filter omitting wavelengths below 470 nm is recommended for liver transplant surgery. This filter has been readily accepted by surgeons and offers a good balance between protection and altered visual color perception. The experimental model, using hemolysis of protoporphyrin-loaded erythrocytes as a measure of phototoxicity, has substantiated theoretical findings on relative filter protection. Liver Transpl 14:1340,1346, 2008. © 2008 AASLD. [source] Phosphodiesterase 5 (PDE 5) inhibitors for the treatment of male erectile disorder: Attaining selectivity versus PDE6MEDICINAL RESEARCH REVIEWS, Issue 3 2006Dmitri Pissarnitski Abstract The role of phosphodiesterase type 5 (PDE5) in the mechanism of male erection has been well understood, and several drugs inhibiting this enzyme are being used for the treatment of erectile dysfunction (ED). Discovery of inhibitors with improved selectivity versus other PDE isozymes could lead to drugs with improved safety profile. Achievement of selectivity versus PDE6, co-inhibition of which results in disturbances of color perception, remains the most challenging aspect of current drug discovery programs. The present review describes several case studies, where significant (>100 fold) selectivity versus PDE6 has been attained via investigation of structure,activity relationships (SAR). Special attention is given to the chemical routes leading to novel chemotypes and allowing efficient exploration of their SAR's. Strategies for attaining inhibitor selectivity discussed below may be applicable for other drug discovery programs. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] Perceptual considerations in the use of colored photographic and video stimuli to study nonhuman primate behaviorAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2006Corri Waitt Abstract The use of photographs, slides, computerized images, and video to study behavior is increasingly being employed in nonhuman primates. However, since these mediums have been designed to simulate natural coloration for normal trichromatic human vision, they can fail to reproduce color in meaningful and accurate ways for viewers with different visual systems. Given the range of color perception that exists both across and within different species, it is necessary to consider this variation in order to discern the suitability of these mediums for experimental use. Because of the high degree of visual similarity among humans, Old World monkeys, and apes, the use of photographic and video stimuli should be acceptable in terms of replicating naturalistic coloration and making noticeable color manipulations. However, among New World primates and prosimians, there exists a considerable degree of variation in color perceptual abilities depending on the species, sex, and allelic combination of the animals involved. Therefore, the use of these mediums to study behavior is problematic for these species, and should be done with caution. Am. J. Primatol. 68:1054,1067, 2006. © 2006 Wiley-Liss, Inc. [source] Manifestation of depressive tendency in color perception and colors utilized in creating a self-portraitCOLOR RESEARCH & APPLICATION, Issue 1 2009Fong-Gong Wu Abstract There are a large number of studies on color and its influence upon human emotions, but there have been only a few studies on the correlation between color and depressive mental disorders. This study used color preference, association, and creation of self-portraits to explore the relationship between color and depressive tendency. In this study, 337 freshman design students participated in the experiment, and the center for epidemiologic studies-depression scale (CES-D) was used to determine the extent of depression in the subjects. After classifying the subject as "depressive tendency" and "no depressive tendency," the semantic differential scale and color association methods were used to explore the subjects' emotional, cognitive, and perceptive responses to Munsell 14 colors. In the final portion of the study, the 233 subjects created a colored self-portrait. The main conclusions found by this study are: (1) when color is used to determine whether subjects have depressive tendency, then the three colors of Yellowish Red, Purple, and Dark Gray are important discriminant variables. (2) those who have depressive tendency (DT) or do not have depressive tendency (NoDT) have similar results in color association, except when viewing dark Gray in association with abstract concepts, wherein DT subjects chose more negative emotional words such as "hopeless," "fear," and "depression"; (3) among the 233 self-portraits, the existence of depressive tendency correlated with the colors used on the face in the self-portrait. From the above conclusions, this study finds that there is much association between depressive tendency and color perception. © 2008 Wiley Periodicals, Inc. Col Res Appl, 34, 84,92, 2009. [source] A quantitative network model for color categorization,COLOR RESEARCH & APPLICATION, Issue 4 2002K. Okajima Abstract To clarify the higher-order mechanism of human color perception, we measured the color appearances of 78 colored lights by an elemental color-scaling method and by a categorical color naming method. The colors covered nearly the entire CIE 1931 xy -chromaticity diagram with three different surrounds. The results showed that firm basic color zones derived by categorical color naming can be mapped with no overlap in an opponent-color response space. We propose a network model with a threshold selector, maximum selectors, and multiplication units with gain factors to generate the categorical color responses quantitatively from the elemental color responses. The model can predict the categorical color naming results in different surround conditions with no change of parameters. This suggests that a nonlinear color vision mechanism for color categorization exists between the primary visual cortex (V1) and the inferior temporal cortex (IT) in the human brain. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 225,232, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10060 [source] | ||||||||||