Thesis (Ph. D.)--Michigan State University. Dept. of Chemistry, 2008. / Title from PDF t.p. (viewed on Aug. 20, 2009) Includes bibliographical references (p. 203-206). Also issued in print.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 1980. / Thesis Advisor(s): Neil, Douglas. Second Reader: Moroney, William. "March 1980." Description based on title screen as viewed on May 25, 2010. DTIC Descriptor(s): Data Displays, Man Machine Systems, Cockpits, Performance (Human), Reaction Time, Pilots, Analysis Of Variance, Theses, Coding, Colors, Errors, Symbols, Cathode Ray Tube Screens, Color Vision, Alphanumeric Displays DTIC Identifier(s): Color Coding. Author(s) subject terms: Coding Techniques, Symbols,Colors, Reaction Time, Performance, Errors, Alphanumerics. Includes bibliographical references (p. 65-66). Also available in print.

Red interior lighting used to preserve dark-adaptation needs to be replaced in military applications by blue/green lighting which is not detectable by 3rd-generation image intensifiers. This study investigated the influence of blue/green as compared to red and white light of equal photopic intensity on subsequent visual acuity , contrast sensitivity and dark-adaptation. Male subjects (n = 90) were assigned to one of 15 treatment conditions (n = 6) as determined by the colour (blue/green, red or white) and intensity (0.1; 0.4; 1.6; 6.4 and 25.6 cd/m²) of the pre-adaptation stimuli. A modified Goldmann/Weekers adaptometer was used to present the preadaptation stimuli, test stimuli and record visual (luminance) thresholds of each subject. Blue/green lighting had the same affect on visual (photopic) acuity and contrast sensitivity as white and red lighting. Blue/green affected visual (absolute) threshold at the start and during the process of dark-adaptation in the same manner as white but not the same as red lighting. White and red lighting did not differ significantly (p < 0.01) at low intensities (mesopic range) but did at the higher intensities (photopic range). After exposure to blue/green and white light, it will take longer to reach the same level of dark-adaptation than after exposure to red. These time differences increase with" increased intensities. The brightness ratio between red and white lights to produce the same dark-adaptation increases with an increase in intensity. At the upper mesopic region the differences between the effects of white and red lighting on subsequent dark-adaptation become irregular due to the inability to accurately equate non-monochromatic lights in the mesopic range.

A visão de cores em vertebrados necessita de pelo menos duas classes de cones, (fotorreceptores presentes na retina) e a existência de um substrato neural para que os fótons de luz sejam comparados, processados e posteriormente resultar na sensação da cor. Primatas do Velho Mundo, incluindo humanos, apresentam visão de cor tricromata, enquanto que primatas do Novo Mundo apresentam um polimorfismo nos genes dos pigmentos visuais e, entre os primatas, são os únicos que podem apresentar indivíduos com visão dicromata ou tricromata. O polimorfismo encontrado em primatas do Novo Mundo ocorre devido à variabilidade dos genes que expressam as opsinas responsáveis por absorver comprimentos de onda médios ou longos. Os estudos genéticos das opsinas são essenciais para compreensão do processamento e da sensação de cores nesses animais, e podem ajudar a entender a evolução da visão de cores nos Primatas. O objetivo deste trabalho é caracterizar a diversidade dos pigmentos visuais (LWS/MWS e SWS1) das espécies de primatas do Novo Mundo através de análises genéticas e descrever a sequência de aminoácidos observados para estimar o pico de sensibilidade espectral das opsinas. Foram coletadas amostras de sangue, fezes e/ou pelo de seis gêneros de primatas provenientes de diferentes regiões do Brasil (Pará, Rio de Janeiro, Rio Grande do Norte e São Paulo) e pertencentes às espécies Cebus apella, Callithrix jacchus, Alouatta clamitans, Alouatta caraya, Lagothrix lagothricha, Ateles belzebuth e Brachyteles arachnoides e posteriormente foram analisados os genes que expressam as opsinas nesses indivíduos. As sequências de aminoácidos encontradas nas posições importantes do gene SWS1 (52, 86, 93, 114 e 118) foram diferentes para algumas espécies. No gene SWS1 as espécies C. apella, L. lagotricha, A. belzebuth e B. arachnoides apresentam a sequência de aminoácidos LLPAT e as espécies C. jacchus, A. caraya e A. clamitans apresentaram a sequência de aminoácidos LLPGT. Foi descoberto que variações de aminoácidos na posição 50 do gene SWS1 em primatas do Novo Mundo podem ser importantes na determinação do pico de absorção espectral dos pigmentos expressos por este gene. Os genes LWS e MWS de indivíduos da espécie C. jacchus foram estudados e os aminoácidos localizados nas posições 180, 277 e 285 das opsinas foram identificados. Os resultados dos alelos encontrados nesses grupos tiveram cinco combinações diferentes (SFT, SYA, SYT, AYA e AYT), os alelos AYA e SYA foram descritos pela primeira vez neste grupo e a partir do resultado genético foi inferido o pico de absorção espectral da opsina. Este trabalho preencheu algumas lacunas da bibliografia e trouxe novas informações a respeito da diversidade genética dos pigmentos visuais em primatas do Novo Mundo / Color vision in vertebrates requires the presence of at least two different classes of cones in the retina, and a neural substrate capable to compare the activation of the different photoreceptors, which ultimately leads to color perception. Old World Monkeys (OWM), including humans, have trichromatic color vision, whereas New World Monkeys (NWM) have visual pigment genes polymorphism and among primates, are the only group with dichromatic or trichromatic individuals in the same species. This polymorphism in NWM occurs due to the variability of genes that express the opsins responsible for absorbing medium or long wavelengths. The genetic studies of color vision are fundamental for the comprehension of color perception in these animals and it could help to understand the color vision evolution in Primates. The aim of this work is to characterize the visual pigment diversity (LWS/MWS and SWS1) in NWM species by genetic analysis and estimate the opsin spectral absorption peak, based on the amino acid sequence. Blood, feces and hair were collected from six primate genres from different regions of Brazil (Pará, Rio de Janeiro, Rio Grande do Norte and São Paulo): Cebus apella, Callithrix jacchus, Alouatta clamitans, Alouatta caraya, Lagothrix lagothricha, Ateles belzebuth and Brachyteles arachnoides. The amino acid sequences found in important positions of the SWS1 gene (52, 86, 93, 114 and 118) were different among some species. In C. apella, L. lagotricha, A. belzebuth and B. arachnoides was found the amino acid sequence LLPAT. In C. jacchus, A. caraya and A. clamitans the amino acid sequence was LLPGT. It was observed in previous studies that residue 50 of the SWS1 gene in the New World primates is important to determining the spectral absorption peak of the visual pigments expressed by this gene. The LWS and MWS genes of C. jacchus have been studied and the amino acids located at positions 180, 277 and 285 have been identified. Five different combinations were found among the individuals analyzed: SFT, SYA, SYT, AYA and AYT. Two alleles, AYA and SYA, were described for the first time in this species. The present study filled some gaps in the literature and brought new information on the genetic diversity of visual pigments in New World primates

O Questionário de Função Visual Infantil (QFVI) é um instrumento para medir o impacto da deficiência visual na criança e em seus familiares. Pode ser utilizado como ferramenta para pesquisas, verificação da eficácia de tratamentos e de diferentes terapêuticas aplicadas, além de auxiliar métodos que intervenham com melhor eficiência, como habilitação e reabilitação visual. O objetivo deste trabalho é estudar a relação entre os domínios Saúde Geral, Saúde Geral da Visão, Competência, Personalidade, Impacto familiar e Tratamento, que compõem o QFVI, e as medidas psicofísicas de acuidade visual (AV) e discriminação de cromaticidade (VC). Este estudo prospectivo, transversal foi realizado no Laboratório de Psicofisiologia Sensorial da Universidade de São Paulo em parceria com o Ambulatório de Estimulação Visual Precoce Setor de Baixa Visão e Reabilitação Visual da Universidade Federal de São Paulo. As crianças convidadas a participarem deste estudo foram alocadas em 2 grupos: Grupo estudo (GE) composto por 32 crianças, com o diagnóstico de deficiência visual, com idade média de 30 meses (dp= 22,3); Grupo controle (GC) composto por 21 crianças, com visão normal e idade média de 34 meses (dp= 26,8). Esses grupos foram submetidos a aplicação do QFVI, e em seguida as avaliações de medida de AV através do teste de Cartões de Acuidade de Teller (CAT), e VC pelo programa Cambridge Colour Test para crianças (CCT Kids). O resultado da aplicação do QFVI, para os grupos de crianças menores de 3 anos, comparados entre os GE e GC, mostrou diferenças significantes entre os seguintes domínios: Saúde Geral da visão (F=24,07 e p<0,001); Competência (F=73,00 e p<0,001); Personalidade (F=10,21 e p=0,010); Impacto Familiar (F=35,30 e p<0,001); Total da qualidade de vida (F=64,06 e p<0,001). No teste de AV pelo CAT, nos grupos de crianças menores de 3 anos, comparados entre os GE e GC, foram observadas diferenças entre: AV de olho direito (OD) (F=12,86 e p<0,001); AV de olho esquerdo (OE) (F=11,09 e p<0,001); AV de ambos os olhos (AO) (F=16,27 e p<0,001). Estas diferenças mostram uma pior pontuação para o GE. Na VC medidos pelo CCT kids, os dados coletados nos grupos de crianças menores de 3 anos, comparados entre os GE e GC, não foram observadas diferenças estatisticamente significativas para os grupos Protan, Tritan, e Deutan para AO. Na aplicação do QFVI, os dados coletados nos grupos de crianças maiores de 3 anos, comparados entre os GE e GC, foram observadas diferenças entre os seguintes domínios: Saúde Geral da visão (F=10,00 e p<0,001); Competência (F=7,03 e p=0,030); Personalidade (F=6,48 e p=0,010); Total da qualidade de vida (F=11,39 e p=0,010). Estas diferenças mostram uma pior pontuação para o GE. No teste de AV pelo CAT, os dados coletados nos grupos de crianças maiores de 3 anos, comparados entre os GE e GC, foram observadas diferenças entre: AV de OD (F=19,25 e p<0,001); AV de OE (F=25,99 e p<0,001); AV de AO (F=15,45 e p<0,001). Estas diferenças mostram uma pior pontuação para o GE. No teste de VC pelo CCT kids, os dados coletados nos grupos de crianças maiores de 3 anos, comparados entre os GE e GC, não foram observadas diferenças estatisticamente significativas para os grupos Protan, Tritan, e ou Deutan. Para o GE, de crianças menores de 3 anos, a correlação negativa entre as funções visuais e o QFVI, está presente entre as seguintes variáveis: Saúde geral da visão e competência. Já para as crianças maiores de 3 anos: Saúde geral da visão, competência, impacto familiar e total da qualidade de vida. Nós concluímos que existem diferenças estatisticamente significativas quando comparados os GE e GC para as funções de acuidade visual e discriminação de cromaticidade, evidenciando a correlação no uso do QFVI e as funções de AV e VC / The Children\'s Visual Function Questionnaire (CVFQ) is an instrument to measure the impact of visual impairment in children and their families. It can be used as a research tool to verify the effectiveness of treatment, therapy and different methods for the visual stimulation and rehabilitation. The aim of this study is to describe the relationship between General Health, General Vision Health, Personality, Family Impact and Treatment subscales of the CVFQ, and psychophysical measures of visual acuity (VA) and chromaticity discrimination (CV). This prospective, cross-sectional study was conducted at the Sensory Psychophysiology Laboratory - University of São Paulo in partnership with the Ambulatory of Visual Stimulation in Sector of Low Vision and Visual Rehabilitation - Federal University of São Paulo. The children who participated in this study were divided into two groups: study group (SG) composed of 32 children with a diagnosis of visual impairment, mean age of 30 months (sd = 22.3); Control group (CG) consisted of 21 children with normal vision and mean age of 34 months (sd = 26.8). Both groups underwent the application of CVFQ, were tested for VA using the Teller Acuity Cards (TAC) test, and CV by the Cambridge Colour Test program for children (Kids CCT). The result of applying the CVFQ to groups of children under three years, when comparing SG and CG, showed significant differences in the following subscales: General Vision Health (F = 24.07, p <0.001); Competence (F = 73.00, p <0.001); Personality (F = 10.21, p = 0.010); Family Impact (F = 35.30, p <0.001); Total quality of life (F = 64.06, p <0.001). In the VA test by the TAC in groups of children under three years, comparing SG with CG, differences were observed in VA right eye (RE) (F = 12.86, p <0.001); VA left eye (LE) (F = 11.09, p <0.001); VA both eyes (BE) (F = 16.27, p <0.001). These differences show a worse score for the SG. In the CV measured by Kids CCT, the data collected in groups of children under three years, comparing SG and CG, no statistically significant differences for protan, tritan and deutan groups were observed for BE. In applying the CVFQ, the data collected from groups of children over three years, comparing SG and CG, differences were observed in the following subscales: General Vision Health (F = 10.00, p <0.001); Competence (F = 7.03, p = 0.030); Personality (F = 6.48, p = 0.010); Total quality of life (F = 11.39, p = 0.010). These differences show a worse score for the SG. In the VA test by the TAC, the data collected in groups of children over three years, comparing SG and CG, differences were observed in: VA RE (F = 19.25, p <0.001); VA LE (F = 25.99, p <0.001); VA BE (F = 15.45, p <0.001). These differences show worse score for the SG. In the CV by Kids CCT, the data collected in groups of children over three years, comparing SG and CG, no statistically significant differences for protan, tritan and deutan groups were observed. For the SG, children under three years, a negative correlation between the visual functions and the CVFQ was present for the following variables: General Vision Health and Competence, while for children over three years, correlations were found for General Vision Health, Competence, Family Impact and General Quality of Life. We conclude that there are statistically significant differences when comparing the SG with the CG for the visual function of VA and CV, and we also demonstrated the sensitivity in the use of CVFQ in reflect VA and CV impairments

Understanding how individual photoreceptor cells factor in the spectral sensitivity of a visual system is essential to explain how they contribute to the visual ecology of the animal in question. Existing methods that model the absorption of visual pigments use templates which correspond closely to data from thin cross-sections of photoreceptor cells. However, few modeling approaches use a single framework to incorporate physical parameters of real photoreceptors, which can be fused, and can form vertical tiers. Akaike’s information criterion (AIC c ) was used here to select absorptance models of multiple classes of photoreceptor cells that maximize information, given visual system spectral sensitivity data obtained using extracellular electroretinograms and structural parameters obtained by histological methods. This framework was first used to select among alternative hypotheses of photoreceptor number. It identified spectral classes from a range of dark-adapted visual systems which have between one and four spectral photoreceptor classes. These were the velvet worm, Principapillatus hitoyensis , the branchiopod water flea, Daphnia magna , normal humans, and humans with enhanced S-cone syndrome, a condition in which S-cone frequency is increased due to mutations in a transcription factor that controls photoreceptor expression. Data from the Asian swallowtail, Papilio xuthus , which has at least five main spectral photoreceptor classes in its compound eyes, were included to illustrate potential effects of model over-simplification on multi-model inference. The multi-model framework was then used with parameters of spectral photoreceptor classes and the structural photoreceptor array kept constant. The goal was to map relative opsin expression to visual pigment concentration. It identified relative opsin expression differences for two populations of the bluefin killifish, Lucania goodei . The modeling approach presented here will be useful in selecting the most likely alternative hypotheses of opsin-based spectral photoreceptor classes, using relative opsin expression and extracellular electroretinography.

Functional traits, particularly those that impact fitness, can shape the ecological and evolutionary relationships among coexisting species of the same trophic level. Thus, examining these traits and properties of their distributions (underdispersion, overdispersion) within communities can provide insights into key ecological interactions (e.g., competition, facilitation) involved in community assembly. For instance, the distribution of floral colors in a community may reflect pollinator-mediated interactions between sympatric plant species, and the phylogenetic distribution of color can inform how evolutionary contingencies can continue to shape extant community assemblages. Additionally, the abundance and species richness of the local habitat may influence the type or strength of ecological interactions among co-occurring species. To evaluate the impact of community size and species richness on mechanisms shaping the distribution of ecologically relevant traits, we examined how floral color (defined by pollinator color vision models) is distributed within co-flowering assemblages. We modeled floral reflectance spectra of 55 co-flowering species using honeybee (Apis mellifera) and syrphid fly (Eristalis tenax) visual systems to assess the distributions of flower color across 14 serpentine seep communities in California. We found that phylogenetic relatedness had little impact on the observed color assemblages. However, smaller seep communities with lower species richness were more overdispersed for flower color than larger, more species-rich communities. Results support that competitive exclusion could be a dominant process shaping the species richness of flower color in smaller-sized communities with lower species richness, but this is less detectable or overwhelmed by other processes at larger, more speciose communities.

In this project a dashboard was created on behalf of the company Combitech who wanted to visualize a part of a workgroup’s information flow in hope of improving their communication. The only restriction was that it could not be interactive. The focus and goal with this study was to explore what factors one should keep in mind when designing a non-interactive dashboard. The two main theories used to guide this work were: information visualization and accessibility (focus on color vision deficiency). Designing digital products with accessibility needs in mind is not standard practice, but needs to be as society is becoming more filled with them. The process of creating the dashboard started with a literature review to read relevant works to gain insight. Interviews and user evaluations were conducted to gather insight from the users. An accessibility evaluation was performed to check for potential accessibility problems with the design. The result of the study suggests that information visualization and accessibility can be used together to produce a non-interactive dashboard that is viewed as both useful and appealing. The aspects used to achieve this were: understanding and involving the users to be able to prioritize information, being aware of how human perception works and how to apply color in an accessible way. / I detta projekt skapades en dashboard på uppdrag av företaget Combitech som ville visualisera en del av en av deras arbetsgruppers informationsflöde i hopp om att förbättra deras kommunikation. Den enda begränsningen var att den inte kunde vara interaktiv. Fokuset och målet med denna studie var att utforska vilka faktorer man bör tänka på när man designar en icke-interaktiv dashboard. De två huvudsakliga teorierna som användes för att styra detta arbete var: informationsvisualisering och tillgänglighet (fokus på defekt färgseende). Att designa digitala produkter med tillgänglighetsbehov i åtanke är inte standardpraxis, men behöver bli det då samhället blir mer fyllt av dem.  Processen att skapa dashboarden började med en litteraturgenomgång för att läsa relevanta verk för att få insikt. Intervjuer och användarutvärderingar genomfördes för att samla åsikter från användarna. En tillgänglighetsutvärdering gjordes för att kontrollera eventuella tillgänglighetsproblem med designen.   Resultatet av studien tyder på att informationsvisualisering och tillgänglighet kan användas tillsammans för att skapa en icke-interaktiv dashboard som ses som både användbar och tilltalande. Aspekterna som användes för att uppnå detta var: förstå och involvera användarna för att kunna prioritera information, vara medveten om hur mänsklig perception fungerar och hur man kan applicera färg på ett tillgängligt sätt.

Models of sensory processing have historically abstracted underlying biological circuits, due to unknown connectivity and/or complexity. In contrast, the use of tractable and anatomically well-characterized model organisms such as the fruit fly Drosophila melanogaster allows us to utilize biological constraints in models of sensory processing to understand underlying circuit mechanisms and make more accurate predictions. This approach has been used to dissect motion vision circuits, but investigations into color vision - a salient visual feature for many animals - have been limited. Here, we investigate the circuit mechanisms of the early color circuit of the fruit fly and assess its information processing capabilities. Using in vivo two-photon calcium imaging and genetic manipulations, we measure the chromatic tuning properties of photoreceptor axons and their primary targets in the medulla neuropil. At the level of photoreceptor axons, we show that opponent processes are the result of a dual mechanism - a direct pathway specific to insect physiology and an indirect pathway found across the animal kingdom. Both pathways are necessary to decorrelate incoming signals and efficiently represent chromatic information. We built an anatomically constrained model that is able to quantitatively reproduce these color opponent responses without fitting synaptic weights. Instead, we used electron-microscopy-derived synaptic count, an anatomically defined measure, as a proxy for synaptic weight, thereby linking structure to function. Downstream of photoreceptors, we find that neurons shift their tuning and become highly selective for particular directions in color space - similar to “hue-selective” neurons in primate cortex. To achieve this selectivity, these neurons require input from all types of photoreceptors and an interneuron that determines the neuron's preferred chromatic direction. We extended our anatomically constrained model to incorporate these downstream neurons and are able to predict their responses, qualitatively and quantitatively.In summary, the detailed reconstruction of the fly circuit anatomy predicts the mechanisms of multiple stages of color information processing and allows us to infer functional roles for each part of the circuit. The circuit motifs, we uncover, are shared across species and hint at convergent mechanisms that underlie the transformation from an opponent neural code to a hue selective code.

This dissertation examined the relationships between color contrast and legibility for digital raster video imagery. CIE colorimetric components were combined into three-dimensional color coordinate systems whose coordinates map one-to-one with the physical energy parameters of all colors. The distance between any two colors' coordinates in these 3-spaces is termed Color-Difference (ΔE). ΔE was hypothesized as a metric of the speed (RS) with which observers possessing normal vision could accurately read random numeral strings of one color displayed against backgrounds of another color. Two studies totaling 32064 practice and experimental trials were conducted. The first study determined that the CIE Uniform Color Spaces are inappropriate for the modeling of RS. Subsequently, a different 3-space geometry and colorimetric component scaling were empirically derived from the Study 1 data to produce a one-dimensional ΔE scale which ” approximates an interval scale of RS. This ΔE scale and others were then applied to the different stimulus conditions in Study 2 to determine the generalizability of such ΔE metrics. The pair of studies is conclusive: several ΔE scales exist which serve equally well to describe or prescribe RS with multicolor CRT raster imagery for a range of character luminances in both positive and negative presentation polarities. These are the Y,u',v', logY,u',v', L*,u',v', and L*,u*,v* rescaled color spaces. Because of its predictive accuracy and simplicity, a luminance—generalized, ΔE—standardized Y,u',v' metric, accounting for 71% and 75% of the RS variability in Studies 1 and 2, respectively, is recommended as the most appropriate metric of emissive display legibility to be tested in these studies. / Ph. D.