Color Discrimination Research Articles

Broad spectrum artificial light at night increases the conspicuousness of camouflaged prey

Abstract The growing global prevalence of energy efficient broad spectrum lighting threatens to disrupt an array of visually guided ecological processes. Broad spectrum lighting likely better enables the discrimination of colour, yet it is potential to increase the conspicuousness of camouflaged prey at night remains little explored. Using a well‐established visual model, we quantified the impacts of four spectrally distinct narrow and broad spectrum lighting technologies on the conspicuousness of three different polymorphic colour variations of intertidal littorinid snail, as viewed by three model predators. Modern broad spectrum lighting technologies increased the conspicuousness of prey compared to 20th‐century narrow spectrum lighting. This effect was most prominent in the yellow colour morphs due to greater contrast with their natural fucoid seaweed background. Synthesis and applications. Our results provide evidence that the global transition to broad spectrum lighting will decrease the efficacy of camouflage at night in nature, potentially altering selective predation, population dynamics and the genetic structure of polymorphic populations. These findings highlight the need for further consideration in environmental management and planning, to ensure habitats are protected from unnecessary exposure to artificial light.

Clinical manifestation of patients with isolated rapid eye movement sleep behavior disorder after modest-to-long disease duration.

Patients with isolated rapid eye movement (REM) sleep behavior disorder (iRBD) are known to be at risk of neurodegenerative diseases but the time process of neurodegeneration remains unclear and its ethnic difference is rarely discussed. The objective of this study was to investigate the clinical manifestation of iRBD according to disease duration in a Korean cohort. Patients who had been diagnosed with iRBD for at least 5 years were tracked and those currently remaining as iRBD were invited for motor, autonomic, olfactory, color discrimination, and cognitive tests. Cross-sectional comparison between patients with iRBD with modest disease duration (5-9.9 years) and long disease duration (≥10 years) was conducted. There were total of 198 patients with iRBD (135 males, 68.2%) tracked, whose average age at diagnosis was 65.9 years. Thirty-three had developed parkinsonism and 17 had developed dementia, resulting in a phenoconversion risk of 35.7% at 10 years. Hazard rate showed a gradually increasing trend over time, beginning from 2.1 conversions per year to 8.5 at 10 years. Patients with iRBD with a long disease duration (n = 19) had slightly higher motor scores than those with a modest duration (n = 82). However, they showed no difference in the frequency of motor abnormality or other clinical markers. There is a possible racial or geographical difference of phenoconversion risk. The progression of neurodegeneration might be very subtle in that patients with iRBD with longer disease duration do not necessarily show higher frequency of neurodegeneration markers.

Colour vision in stomatopod crustaceans: more questions than answers.

ABSTRACTStomatopod crustaceans, or mantis shrimps, are known for their extensive range of spectral sensitivity but relatively poor spectral discrimination. Instead of the colour-opponent mechanism of other colour vision systems, the 12 narrow-band colour channels they possess may underlie a different method of colour processing. We investigated one hypothesis in which the photoreceptors are proposed to act as individual wave-band detectors, interpreting colour as a parallel pattern of photoreceptor activation, rather than a ratiometric comparison of individual signals. This different form of colour detection has been used to explain previous behavioural tests in which low-saturation blue was not discriminated from grey, potentially because of similar activation patterns. Results here, however, indicate that the stomatopod Haptosquilla trispinosa was able to easily distinguish several colours, including blue of both high and low saturation, from greys. The animals did show a decrease in performance over time in an artificially lit environment, indicating plasticity in colour discrimination ability. This rapid plasticity, most likely the result of a change in opsin (visual pigment) expression, has now been noted in several animal lineages (both invertebrate and vertebrate) and is a factor we suggest needs attention and potential re-examination in any colour-based behavioural tests. As for stomatopods, it remains unclear why they achieve poor colour discrimination using the most comprehensive set of spectral sensitivities in the animal kingdom and also what form of colour processing they may utilise.

Impaired Color Recognition in HCN1 Epilepsy: A Single Case Report.

Variants in HCN1 are associated with a range of epilepsy syndromes including developmental and epileptic encephalopathies. Here we describe a child harboring a novel de novo HCN1 variant, E246A, in a child with epilepsy and mild developmental delay. By parental report, the child had difficulty in discriminating between colors implicating a visual deficit. This interesting observation may relate to the high expression of HCN1 channels in rod and cone photoreceptors where they play an integral role in shaping the light response. Functional analysis of the HCN1 E246A variant revealed a right shift in the voltage dependence of activation and slowing of the rates of activation and deactivation. The changes in the biophysical properties are consistent with a gain-of-function supporting the role of HCN1 E246A in disease causation. This case suggests that visual function, including color discrimination, should be carefully monitored in patients with diseases due to HCN1 pathogenic variants.

Potential value of color vision aids for varying degrees of color vision deficiency.

Red-green color vision deficiency (CVD) is the most common single locus genetic disorder in humans, affecting approximately 8% of males and 0.4% of females [G. H. M. Waaler, Acta Ophthalmol.5, 309 (2009)10.1111/j.1755-3768.1927.tb01016.x]; however, only about 1/4 of CVD individuals are dichromats who rely on only two cone types for color vision. The remaining 3/4 are anomalous trichromats whose CVD is milder, being based on three cone types, and who still perform remarkably well on many color-based tasks. To illustrate this, we have developed an algorithm that computes the relative loss of color discrimination in red-green CVD individuals with varying degrees of deficiency and accurately simulates their color experience for color normal observers. The resulting simulation illustrates the large gap in color discrimination between dichromats and even the most severe anomalous trichromats, showing that, relative to dichromats, the majority of anomalous trichromats can function without aids for color vision deficiency.

Ignition measurement of non-premixed propane with varying co-flowing AIR through high-speed schlieren stereoscopic colour imaging

The flame kernel propagation characteristics stemmed from the spark ignition of low-Re, non-premixed propane (C3H8) under varying air co-flow conditions were studied using DFCD (Digital Flame Colour Discrimination) incorporated stereoscopic image processing technique. The current work focused on the viability of obtaining the combustion initiating kernel propagation speed (SP), equivalence ratio (Φ) and kernel depth (z) characteristics simultaneously as these parameters are important in the fundamental combustion theories and highly desired in the field of practical burner monitoring and diagnostics. Through the superimposition of schlieren and DFCD-enhanced colour images, the observed spatial location of kernel spearhead was found to conform to the disturbance front observed from the schlieren visualisation. Flame stretch principle was applied to experimentally determine the un-stretched kernel propagation speeds (SP,O). Concurrently, the estimation of the temporal state of reactant mixture equivalence ratio (Φe) variation was made using DFCD-segregated spatial colour signal characteristics. Further comparison were made against the CHEMKIN simulated results of un-stretched laminar flame speed (SL,O) at different Φ. The experimentally determined SP,O values were found to overlap the SL,O range corresponding to the measured Φe. The steady occurrence of digital colour fidelity observed for all considered cases suggest that the most reactive mixture fraction (ξMR) path followed by the kernel occurred in the fuel-rich premixed Φ condition (approximately Φe = 1.34 to 1.40). Furthermore, stereoscopic reconstruction of DFCD-enhanced flame colour images provided additional dimensional linkage to correlate the dimensional-spectral variation along with changes in combustion flow conditions. The dimensional-spectral property, through the computation of local colour ratio and stereoscopically reconstructed z, illustrated linearity in both the time domain and in temporal cross-correlation with Φe. The observed shift of the cross-correlated cluster towards the fuel-richer Φe condition is coherent to the corresponding increase in Re and exemplifies the observed conformance of the derived SL,O and Φe to properties of premixed combustion along the propagation front potentially denoting the path of ξMR.

Color Discrimination Provides Insight into the Relationship between Personality Cognition and Brain Morphology in the Western Mosquitofish (Gambusia affinis)

Recent studies on the differences in cognitive ability between individuals focused on two aspects: one is whether the individual differences in cognitive ability are related to brain size, the other is whether they pertain to certain personality traits. To explore these two hypotheses, we tested the personality traits, cognitive abilities, and brain volumes of western mosquitofish (Gambusia affinis). First, a color preference test was conducted to select two unbiased colors for G. affinis for subsequent cognitive tests. The results showed that G. affinis had a great preference for red and green to yellow and blue; therefore, the red-green combination was selected for the study of cognitive abilities. Then, we explored the relationship among cognition, personality, and brain morphology through cognitive abilities tests, personality traits, and brain volume measurements. We found that there was a trade-off among cognition, personality, and brain morphology. For example, more active individuals found food faster, but had also poor memory; Those individuals with larger corpus cerebelli were bolder while they were less likely to find food; The individuals that found food faster were more active and had a smaller inferior lobe. The color preference test provides a reliable way for selecting unbiased colors for behavioral studies in G. affinis. Meanwhile, our study indicates that there exists a balance mechanism among cognition, personality, and brain morphology.

The Neural Signature of Visual Learning Under Restrictive Virtual-Reality Conditions.

Honey bees are reputed for their remarkable visual learning and navigation capabilities. These capacities can be studied in virtual reality (VR) environments, which allow studying performances of tethered animals in stationary flight or walk under full control of the sensory environment. Here, we used a 2D VR setup in which a tethered bee walking stationary under restrictive closed-loop conditions learned to discriminate vertical rectangles differing in color and reinforcing outcome. Closed-loop conditions restricted stimulus control to lateral displacements. Consistently with prior VR analyses, bees learned to discriminate the trained stimuli. Ex vivo analyses on the brains of learners and non-learners showed that successful learning led to a downregulation of three immediate early genes in the main regions of the visual circuit, the optic lobes (OLs) and the calyces of the mushroom bodies (MBs). While Egr1 was downregulated in the OLs, Hr38 and kakusei were coincidently downregulated in the calyces of the MBs. Our work thus reveals that color discrimination learning induced a neural signature distributed along the sequential pathway of color processing that is consistent with an inhibitory trace. This trace may relate to the motor patterns required to solve the discrimination task, which are different from those underlying pathfinding in 3D VR scenarios allowing for navigation and exploratory learning and which lead to IEG upregulation.

Visual learning in a virtual reality environment upregulates immediate early gene expression in the mushroom bodies of honey bees

Free-flying bees learn efficiently to solve numerous visual tasks. Yet, the neural underpinnings of this capacity remain unexplored. We used a 3D virtual reality (VR) environment to study visual learning and determine if it leads to changes in immediate early gene (IEG) expression in specific areas of the bee brain. We focused on kakusei, Hr38 and Egr1, three IEGs that have been related to bee foraging and orientation, and compared their relative expression in the calyces of the mushroom bodies, the optic lobes and the rest of the brain after color discrimination learning. Bees learned to discriminate virtual stimuli displaying different colors and retained the information learned. Successful learners exhibited Egr1 upregulation only in the calyces of the mushroom bodies, thus uncovering a privileged involvement of these brain regions in associative color learning and the usefulness of Egr1 as a marker of neural activity induced by this phenomenon.

Retina-Inspired Color-Cognitive Learning via Chromatically Controllable Mixed Quantum Dot Synaptic Transistor Arrays.

Artificial photonic synapses are emerging as a promising implementation to emulate the human visual cognitive system by consolidating a series of processes for sensing and memorizing visual information into one system. In particular, mimicking retinal functions such as multispectral color perception and controllable nonvolatility is important for realizing artificial visual systems. However, many studies to date have focused on monochromatic-light-based photonic synapses, and thus, the emulation of color discrimination capability remains an important challenge for visual intelligence. Here, an artificial multispectral color recognition system by employing heterojunction photosynaptic transistors consisting of ratio-controllable mixed quantum dot (M-QD) photoabsorbers and metal-oxide semiconducting channels is proposed. The biological photoreceptor inspires M-QD photoabsorbers with a precisely designed red (R), green (G), and blue (B)-QD ratio, enabling full-range visible color recognition with high photo-to-electric conversion efficiency. In addition, adjustable synaptic plasticity by modulating gate bias allows multiple nonvolatile-to-volatile memory conversion, leading to chromatic control in the artificial photonic synapse. To ensure the viability of the developed proof of concept, a 7 × 7 pixelated photonic synapse array capable of performing outstanding color image recognition based on adjustable wavelength-dependent volatility conversion is demonstrated.

Human perception of color differences using computer vision system measurements of raw pork loin

In the food industry, product color plays an important role in influencing consumer choices. Yet, there remains little research on the human ability to perceive differences in product color; therefore, preference testing is subjective rather than based on quantitative colors. Using a de-centralized computer-aided systematic discrimination testing method, we ascertain consumers' ability to discern between systematically varied colors. As a case study, the colors represent the color variability of fresh pork as measured by a computer vision system. Our results indicate that a total color difference (ΔE) of approximately 1 is discriminable by consumers. Furthermore, we ascertain that a change in color along the b*-axis (yellowness) in CIELAB color space is most discernable, followed by the a*-axis (redness) and then the L*-axis (lightness). As developed, our web-based discrimination testing approach allows for large scale evaluation of human color perception, while these quantitative findings on meat color discrimination are of value for future research on consumer preferences of meat color and beyond.

Contributed Session I: FInD Color Detection and Discrimination in adults with and without color vision deficits: Preliminary results

Color vision deficits are important biomarkers, however, existing tests (e.g., Hardy-Rand-Rittler (HRR) & Farnsworth-Munsell 100 hue test (FM100)) are insensitive and time consuming to administer. FInD is a validated computer-based, generalisable, rapid, self-administered paradigm. We describe FInD Color Detection & FInD Color Discrimination and compare performance against HRR & FM100 tests in 9 color-typical and 4 atypical observers. Chromatic stimuli were presented on a luminance-gamma and cone-isolating calibrated display in 3 charts, each containing 4×4 cells. Each cell contained 1 (detection) or 2 (discrimination) gaussian chromatic patches in 8 Hz luminance noise. Observers reported whether a stimulus was present or whether the 2 stimuli were different in color, respectively. D' was calculated for short, medium or long wavelength-isolating stimuli (detection) or for hue differences in HSV space, centered on the 3 primary and 3 confusion axes at 50% and 100% saturation (discrimination). Detection and Discrimination thresholds for atypical observers were higher than for typical observers, with selective elevation of detection and discrimination thresholds corresponding to classic color deficits. FInD Color Detection & Discrimination tests rapidly and easily identify chromatic sensitivity deficits along the visual pathways and may provide a valuable diagnostic tool.

Sensitive optical thermometer via efficient energy transfer in dual-emitting thermochromic YNbO4:Bi3+, Eu3+ phosphor

The remote and non-invasive optical thermometer exploiting fluorescence intensity ratio technology is of great importance in various intelligent optoelectronic sensors. Dual-emitting YNbO4:Bi3+, Eu3+ phosphor is synthesized and investigated for the development of temperature sensing materials. The phosphor excited at 318 nm shows a blue broad band emission and several red sharp peaks. The value of Bi3+→Eu3+ energy transfer can reach 98.2% when Eu3+ doping content is 0.14. Benefiting from diverse thermal response behaviors due to Bi3+ and Eu3+ ions completely different electronic configurations, a dual-emitting optical thermometer is designed. The maximum values of absolute and relative sensitivities are as high as 2.51% K−1 at 473 K and 1.43% K−1 at 423 K, respectively. The thermochromic phosphor possesses a great chromaticity shift (ΔE = 317×10−3) with temperature. Based on superior color discriminability, visual colorimetry temperature measurement relied on thermal characteristic is proposed. All the results demonstrate that YNbO4:0.01Bi3+, 0.005Eu3+ phosphor as a sensitive and reliable optical thermometer has great potentials in temperature measurement.

Cognitive flexibility and aging in coyotes (Canis latrans).

Cognitive flexibility evolves in species that live in complex and dynamic social systems and habitats and may enable species to better cope with anthropogenic habitat modification. Aging may also impact the cognitive abilities of canids. Coyotes (Canis latrans) and domestic dogs (Canis lupus familiaris) differ markedly in their social and trophic ecology but have both been highly successful in adapting to human-modified ecosystems. Aging dogs develop a form of dementia that mirrors Alzheimer's disease in humans, but it is unknown whether similar cognitive deficits develop with age in coyotes and other wild canids. In this study, we modified a spatial serial reversal-learning test that was sensitive to cognitive aging in pet dogs to test cognitive flexibility in captive coyotes. We also performed a second experiment using a color discrimination task to test for flexible rule learning. A total of 19 of 20 coyotes demonstrated the ability to track shifts in spatial reward contingencies and learned to rapidly complete reversals by using a win-stay, lose-shift strategy. In addition, coyotes inhibited prepotent win-stay choices to acquire the color discrimination task. These findings suggest that behavioral flexibility may help coyotes to detect and respond appropriately to both rapid fluctuations and gradual changes in ecological conditions. Performance did not differ between coyotes and previously tested dogs, but similar to dogs, behavioral flexibility declined with age in adult coyotes. Thus, cognitive decline and flexibility may be conserved among canines pending additional studies on other Canis species. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effect of Age and Refractive Error on Local and Global Visual Perception in Chinese Children and Adolescents.

PurposeThis study investigated the impact of age and myopia on visual form perception among Chinese school-age children.MethodsThis cross-sectional study included 1,074 students with a mean age of 12.1 ± 4.7 (range = 7.3–18.9) years. The mean spherical equivalence refraction (SER) of the participants was −1.45 ± 2.07 D. All participants underwent distance visual acuity (VA), refraction measurement and local and global visual form perception test including orientation, parallelism, collinearity, holes and color discrimination tasks.ResultsThe reaction times of emmetropes were slower than those of myopic and high myopic groups on both local (orientation, parallelism, and collinearity) and global discrimination tasks (all p < 0.05). A reduction in reaction times was found with increasing age on both local and global discrimination tasks (all p < 0.05). Age was significantly associated with both local and global visual perception performance after adjusting for gender, visual acuity and SER (orientation, β = −0.54, p < 0.001; parallelism, β = −0.365, p < 0.001; collinearity, β = −0.28, p < 0.001; holes, β = −0.319, p < 0.001; color, β = −0.346, p < 0.001).ConclusionsThis study revealed that both local and global visual perception improve with age among Chinese children and that myopes seem to have better visual perception than emmetropes.

Insect visual sensitivity to long wavelengths enhances colour contrast of insects against vegetation

The sensitivity of animal photoreceptors to different wavelengths of light strongly influence the perceived visual contrast of objects in the environment. Outside of the human visual wavelength range, ultraviolet sensitivity in many species provides important and behaviourally relevant visual contrast between objects. However, at the opposite end of the spectrum, the potential advantage of red sensitivity remains unclear. We investigated the potential benefit of long wavelength sensitivity by modelling the visual contrast of a wide range of jewel beetle colours against flowers and leaves of their host plants to hypothetical insect visual systems. We find that the presence of a long wavelength sensitive photoreceptor increases estimated colour contrast, particularly of beetles against leaves. Moreover, under our model parameters, a trichromatic visual system with ultraviolet (λmax = 355 nm), short (λmax = 445 nm) and long (λmax = 600 nm) wavelength photoreceptors performed as well as a tetrachromatic visual system, which had an additional medium wavelength photoreceptor (λmax = 530 nm). When we varied λmax for the long wavelength sensitive receptor in a tetrachromatic system, contrast values between beetles, flowers and leaves were all enhanced with increasing λmax from 580 nm to at least 640 nm. These results suggest a potential advantage of red sensitivity in visual discrimination of insect colours against vegetation and highlight the potential adaptive value of long wavelength sensitivity in insects.

Combined influence of medication and symptom severity on visual processing in bipolar disorder

Previous studies have reported visual impairments in patients with bipolar disorder (BPD), but unclear were whether clinical variables would be associated with those disturbances. Here, we investigate the relationship between visual functioning, in terms of color discrimination, and the impact of BPD duration, mood state, and the patients' medication. Forty-five participants (25–45 years old) were recruited for this study. Color discrimination was performed using the Cambridge Colour Test. Serial multiple mediations were run to investigate the assumption of association between color discrimination and the clinical variables. Our findings showed that, compared with healthy controls, BPD patients' performance was worse for the Protan, Deutan, and Tritan vectors, revealing deterioration of color discrimination. In addition, the mediation analyses revealed a strong direct (p < .001) and moderate-to-high indirect effects (p < .01) of medication and symptom severity on color discrimination. Overall, both longer the duration of the disease and greater the symptom severity of BPD patients resulted in worse performance. It highlights the importance of examining the wider clinical context of an affective disorder to understand how it affects visual processing in this population.

Three-Year Changes in Visual Function in the Placebo Group of a Randomized Double-Blind International Multicenter Safety Study: Analysis of Electroretinography, Perimetry, Color Vision, and Visual Acuity in Individuals With Chronic Stable Angina Pectoris.

PurposeTo determine whether significant deteriorations in objective (electroretinography [ERG]) and subjective (standard automated and semi-automated kinetic perimetry; color discrimination; and best-corrected visual acuity) tests of visual function, potentially attributable to aging, occurred in the group randomized to placebo of a 3-year prospective multicenter ocular safety study of ivabradine for chronic stable angina pectoris.MethodsThe multicenter trial was conducted at 11 international ophthalmic centers. Changes in visual function between baseline and month 36 were analyzed by means of a two-tailed Wilcoxon signed-rank test, based on the Hodges and Lehman estimator of the median difference, with the 95% confidence intervals derived by Walsh averages.ResultsThirty-eight participants from the placebo group completed the study (mean [SD], age, 62.7 [8.1] years). The group exhibited in each eye small, but statistically significant, reductions in the amplitudes of the dark-adapted (DA) ERG 3.0 a-wave, and light-adapted (LA) 3.0 b-wave, as well as increases in peak time for the DA 0.01 b-wave, DA 3.0 a-wave, LA 3.0 b-wave, and LA 3.0 30-Hz flicker response and in the isopter area I3e of the visual field.ConclusionsStatistically significant deteriorations occurred in visual function over a period of 3 years, potentially attributable to age, within a group of individuals with chronic stable angina pectoris and unremarkable ophthalmological findings other than those attributable to age.Translational RelevanceA longitudinal correction factor for age-related change in visual function may be useful in future trials to determine whether an observed deterioration in visual function is related to intervention or to aging.

Cognitive Phenotypic Plasticity: Environmental Enrichment Affects Learning but Not Executive Functions in a Teleost Fish, Poecilia reticulata.

Simple SummaryEnvironmental enrichment is extremely important for an individual’s neural, cognitive and behavioral development. Emerging animal models, such as teleost fish, may contribute to our understanding of enrichment-driven cognitive plasticity. We studied the cognitive consequences of living in enriched conditions in Poecilia reticulata. In particular, we compared subjects raised alone in a barren aquarium versus subjects exposed to enriched aquaria (with conspecifics, natural substrate, plants, and live prey) in three different cognitive tasks to measure learning, inhibitory control, and cognitive flexibility. Our results showed that guppies from the enriched aquaria learned a color discrimination faster compared to the subject raised in barren conditions. However, in the two remaining cognitive tasks, we found no effect from the treatment, suggesting that enrichment does not affect inhibitory control and cognitive flexibility. This study reveals that enrichment-driven plasticity affects only specific cognitive abilities.Many aspects of animal cognition are plastically adjusted in response to the environment through individual experience. A remarkable example of this cognitive phenotypic plasticity is often observed when comparing individuals raised in a barren environment to individuals raised in an enriched environment. Evidence of enrichment-driven cognitive plasticity in teleost fish continues to grow, but it remains restricted to a few cognitive traits. The purpose of this study was to investigate how environmental enrichment affects multiple cognitive traits (learning, cognitive flexibility, and inhibitory control) in the guppy, Poecilia reticulata. To reach this goal, we exposed new-born guppies to different treatments: an enrichment environment with social companions, natural substrate, vegetation, and live prey or a barren environment with none of the above. After a month of treatment, we tested the subjects in a battery of three cognitive tasks. Guppies from the enriched environment learned a color discrimination faster compared to guppies from the environment with no enrichments. We observed no difference between guppies of the two treatments in the cognitive flexibility task, requiring selection of a previously unrewarded stimulus, nor in the inhibitory control task, requiring the inhibition of the attack response toward live prey. Overall, the results indicated that environmental enrichment had an influence on guppies’ learning ability, but not on the remaining cognitive functions investigated.

Elucidating the Common Basis for Task-Dependent Differential Manifestations of Category Advantage: A Decision Theoretic Approach.

Cross-category hues are differentiated easier than otherwise equidistant hues that belong to the same linguistic category. This effect is typically manifested through both accuracy and response time gains in tasks with a memory component, whereas only response times are affected when there is no memory component. This raises the question of whether there is a common generative process underlying the differential behavioral manifestations of category advantage in color perception. For instance, within the framework of noisy evidence accumulation models, changes in accuracy can be readily attributed to an increase in the efficacy of perceptual evidence integration (after controlling for threshold setting), whereas changes in response time can also be attributed to shorter nondecisional delays (e.g., due to facilitated signal detection). To address the latent decision processes underlying category advantage across different behavioral demands, we introduce a decision-theoretic perspective (i.e., diffusion decision model) to categorical color perception in three complementary experiments. In Experiment 1, we collected data from a binary color naming task (1) to determine the green-blue boundary in our sample and (2) to trace how parameter estimates of interest in the model output change as a function of color typicality. In Experiments 2 and 3, we used same-different task paradigms (with and without a memory component, respectively) and traced the category advantage in color discrimination in two parameters of the diffusion decision model: nondecision time and drift rate. An increase in drift rate predominantly characterized the category advantage in both tasks. Our results show that improved efficiency in perceptual evidence integration is a common driving force behind different manifestations of category advantage.