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1.
J Vis ; 20(3): 10, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32232375

RESUMO

Attention shifts to particular objects in the visual field can distort perceptual location judgments. Visual stimuli are perceived to be shifted away from the current focus of attention (the attentional repulsion effect [ARE]). Although links between repulsion effects and stimulus-driven exogenous attentional capture have been demonstrated conclusively, it remains disputed whether AREs can also be elicited as a result of feature-guided attention shifts that are controlled by endogenous task sets. Here we demonstrate that this is indeed the case. Color singleton cues that appeared together with equiluminant gray items triggered repulsion effects only if they matched a current task-relevant color but not when their color was irrelevant. When target-color and nontarget-color singleton cues appeared in the same display, AREs emerged relative to the position of the target-color cue. By obtaining independent behavioral measures of perceptual repulsion and electrophysiological measures of attentional capture by target-color cues, we also showed that these two phenomena are correlated. Individuals who were more susceptible to attentional capture also produced larger AREs. These results confirm the existence of links between task-set contingent attentional capture and AREs. They also provide the first direct demonstration of the attentional nature of these effects with online brain activity measures: perceptual repulsion arises as the result of prior feature-guided attention shifts to specific locations in the visual field.


Assuntos
Atenção/fisiologia , Percepção de Cores/fisiologia , Fixação Ocular/fisiologia , Campos Visuais/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
2.
J Vis ; 20(3): 7, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32232377

RESUMO

Color constancy involves disambiguating the spectral characteristics of lights and surfaces, for example to distinguish red in white light from white in red light. Solving this problem appears especially challenging for bluish tints, which may be attributed more often to shading, and this bias may underlie the individual differences in whether people described the widely publicized image of #thedress as blue-black or white-gold. To probe these higher-level color inferences, we examined neural correlates of the blue-bias, using frequency-tagging and high-density electroencephalography to monitor responses to 3-Hz alternations between different color versions of #thedress. Specifically, we compared relative neural responses to the original "blue" dress image alternated with the complementary "yellow" image (formed by inverting the chromatic contrast of each pixel). This image pair produced a large modulation of the electroencephalography amplitude at the alternation frequency, consistent with a perceived contrast difference between the blue and yellow images. Furthermore, decoding topographical differences in the blue-yellow asymmetries over occipitoparietal channels predicted blue-black and white-gold observers with over 80% accuracy. The blue-yellow asymmetry was stronger than for a "red" versus "green" pair matched for the same component differences in L versus M or S versus LM chromatic contrast as the blue-yellow pair and thus cannot be accounted for by asymmetries within either precortical cardinal mechanism. Instead, the results may point to neural correlates of a higher-level perceptual representation of surface colors.


Assuntos
Vestuário , Percepção de Cores/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Neurônios Retinianos/fisiologia , Adulto , Eletroencefalografia , Feminino , Humanos , Individualidade , Iluminação/normas , Masculino , Adulto Jovem
3.
Nat Commun ; 11(1): 1852, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32296062

RESUMO

Much of our world changes smoothly in time, yet the allocation of attention is typically studied with sudden changes - transients. A sizeable lag in selecting feature information is seen when stimuli change smoothly. Yet this lag is not seen with temporally uncorrelated rapid serial visual presentation (RSVP) stimuli. This suggests that temporal autocorrelation of a feature paradoxically increases the latency at which information is sampled. To test this, participants are asked to report the color of a disk when a cue was presented. There is an increase in selection latency when the disk's color changed smoothly compared to randomly. This increase is due to the smooth color change presented after the cue rather than extrapolated predictions based on the color changes presented before. These results support an attentional drag theory, whereby attentional engagement is prolonged when features change smoothly. A computational model provides insights into the potential underlying neural mechanisms.


Assuntos
Percepção Visual/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Percepção de Cores/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
4.
Water Res ; 177: 115773, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32320850

RESUMO

True water color (TWC) is an important water quality indicator. However, despite many efforts for standardization of methods for TWC determination, there is still no consistency between visual and spectroscopic techniques. This study demonstrates that standard spectroscopic methods overestimate visual data from 21 to 47%, depending on methods involved. To retrieve relevant true water color values from spectral data, a new spectroscopic method is proposed. The method is based on the mathematical model of color perception by the standard observer implementing the dE2000 color difference in the L∗a∗b color space as calculated between blank and water samples. The method showed good agreement with the visual methods (comparator method and determination in Nessler cylinders) and the mean values between these methods. The mean relative difference between the proposed method and the mean of the two visual methods is only 2%. The method precision is independent from TWC in all measurement ranges and has Sr 0.3 mgPt-Co L-1 (df = 98), which is at least three times lower than for the standard methods. As such, it shows higher accuracy and precision. As a result, the proposed method can be used for TWC determination in environmental samples from 3.3 to 500 mgPt-Co L-1 with SD 0.3 mgPt-Co L-1 in all measuring ranges, making sample dilution unnecessary.


Assuntos
Percepção de Cores , Água , Cor , Espectrofotometria , Análise Espectral
5.
J Vis ; 20(3): 3, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32181859

RESUMO

In paradigms of visual search where the search feature (say color) can change from trial to trials, responses are faster for trials where the search color is repeated than when it changes. This is a clear example of "priming" of attention. Here we test whether the priming effects can be revealed by pupillometry, and also whether they are related to autistic-like personality traits, as measured by the Autism-Spectrum Quotient (AQ). We repeated Maljkovic and Nakayama's (1994) classic priming experiment, asking subjects to identify rapidly the shape of a singleton target defined by color. As expected, reaction times were faster when target color repeated, and the effect accumulated over several trials; but the magnitude of the effect did not correlate with AQ. Reaction times were also faster when target position was repeated, again independent of AQ. Presentation of stimuli caused the pupil to dilate, and the magnitude of dilation was greater for switched than repeated trials. This effect did not accumulate over trials, and did not correlate with the reaction times difference, suggesting that the two indexes measure independent aspects of the priming phenomenon. Importantly, the amplitude of pupil modulation correlated negatively with AQ, and was significant only for those participants with low AQ. The results confirm that pupillometry can track perceptual and attentional processes, and furnish useful information unobtainable from standard psychophysics, including interesting dependencies on personality traits.


Assuntos
Transtorno Autístico/fisiopatologia , Percepção de Cores/fisiologia , Percepção de Forma/fisiologia , Pupila/fisiologia , Priming de Repetição/fisiologia , Adulto , Feminino , Humanos , Masculino , Psicofísica , Tempo de Reação , Inquéritos e Questionários , Adulto Jovem
6.
J Vis ; 20(3): 5, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32196068

RESUMO

Previous electroencephalographic research on attentional salience did not fully capture the complexities of low-level vision, which relies on both cone-opponent chromatic and cone-additive luminance mechanisms. We systematically varied color and luminance contrast using a visual search task for a higher contrast target to assess the degree to which the salience-computing attentional mechanisms are constrained by low-level visual inputs. In our first experiment, stimuli were defined by contrast that isolated chromatic or luminance mechanisms. In our second experiment, targets were defined by contrasts that isolated or combined achromatic and chromatic mechanisms. In both experiments, event-related potential waveforms contralateral and ipsilateral to the target were qualitatively different for chromatic- compared to luminance-defined stimuli. The same was true of the difference waves computed from these waveforms, with isoluminant stimuli eliciting a mid-latency posterior contralateral negativity (PCN) component and achromatic stimuli eliciting a complex of multiple components, including an early posterior contralateral positivity followed by a late-latency PCN. Combining color with luminance resulted in waveform and difference wave patterns equivalent to those of achromatic stimuli. When large levels of chromaticity contrast were added to targets with small levels of luminance contrast, PCN latency was speeded. In conclusion, the mechanisms underlying attentional salience are constrained by the low-level inputs they receive. Furthermore, speeded PCN latencies for stimuli that combine color and luminance signals compared to stimuli that contain luminance alone demonstrate that color and luminance channels are integrated during pre-attentive visual processing, before top-down allocation of attention is triggered.


Assuntos
Adaptação Ocular/fisiologia , Percepção de Cores/fisiologia , Neurônios Retinianos/fisiologia , Percepção Visual/fisiologia , Adulto , Sensibilidades de Contraste/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Adulto Jovem
7.
J Vis Exp ; (156)2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32176205

RESUMO

The Stroop task in its many variations has been used in fields such as psychology, linguistics, and neuroscience to examine questions regarding the automaticity of reading, language processing, and cognitive control, among others. When looking at bilingual individuals, this task can be used to obtain measures of language interference and control in both a bilingual's first language (L1) and second language (L2), as well as for testing the bilingual advantage hypothesis. The Stroop task presents participants with color terms written in congruent colors (e.g., the word RED written in red font), incongruent colors (e.g., the word RED written in green font), in addition to noncolor terms for control (e.g., the word TREE presented in any color), and uses the reaction times from the different conditions to assess the degree of interference and facilitation. In the covert version of the Stroop bilingual task (i.e., participants respond by pressing a button rather than naming aloud), stimuli in the L1 and the L2 are typically presented in separate blocks. While this allows for a simple, yet effective assessment of processing and cognitive control in each language, it fails to capture any potential differences in processing and control within bilingual young adult groups. The present task combines single-language blocks with a novel mixed-language block to increase the level of difficulty of the task, thus making it suitable for testing cognitive control in young adults. Representative results showing differences between performance in the single-language vs. mixed-language blocks are presented, and the benefits of a mixed-language block are discussed.


Assuntos
Idioma , Multilinguismo , Teste de Stroop , Protocolos Clínicos , Percepção de Cores , Feminino , Humanos , Masculino , Tempo de Reação , Leitura , Adulto Jovem
9.
Proc Biol Sci ; 287(1921): 20192731, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32097588

RESUMO

A long-standing hypothesis in ecology and evolution is that trichromatic colour vision (the ability to distinguish red from green) in frugivorous primates has evolved as an adaptation to detect conspicuous (reddish) fruits. This could provide a competitive advantage over dichromatic frugivores which cannot distinguish reddish colours from a background of green foliage. Here, we test whether the origin, distribution and diversity of trichromatic primates is positively associated with the availability of conspicuous palm fruits, i.e. keystone fruit resources for tropical frugivores. We combine global data of colour vision, distribution and phylogenetic data for more than 400 primate species with fruit colour data for more than 1700 palm species, and reveal that species richness of trichromatic primates increases with the proportion of palm species that have conspicuous fruits, especially in subtropical African forests. By contrast, species richness of trichromats in Asia and the Americas is not positively associated with conspicuous palm fruit colours. Macroevolutionary analyses further indicate rapid and synchronous radiations of trichromats and conspicuous palms on the African mainland starting 10 Ma. These results suggest that the distribution and diversification of African trichromatic primates is strongly linked to the relative availability of conspicuous (versus non-conspicuous) palm fruits, and that interactions between primates and palms are related to the coevolutionary dynamics of primate colour vision systems and palm fruit colours.


Assuntos
Arecaceae/fisiologia , Evolução Biológica , Visão de Cores , Frutas , Primatas/fisiologia , Adaptação Fisiológica , Animais , Percepção de Cores , Folhas de Planta
10.
PLoS One ; 15(2): e0229223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32101573

RESUMO

We investigated the effects of voluntary hand movements and continuously present objects on the automatic detection of deviant stimuli in a passive oddball paradigm. The visual mismatch negativity (vMMN) component of event-related potentials (ERPs) was measured as the index of automatic deviant detection. The stimuli were textures consisting of parallel, oblique bars with frequent (standard) and infrequent (deviant) orientation. Traditional vMMN was measured by the difference between ERPs to frequent (standard) and infrequent (deviant) textures. Additionally, we measured 'genuine' vMMN by comparing the ERPs to deviant and control textures in the equal probability procedure. Compatible and incompatible hand movement directions to the standard texture had no influence on 'traditional' vMMN and elicited no 'genuine' vMMN. However, the deviant texture elicited 'genuine' vMMN if the orientation of a continuously present rectangle was different from the standard (and identical to the deviant) texture orientation. Our results suggest that the direction of voluntary hand movement and the orientation of task-irrelevant visual patterns do not acquire common memory representation, but a continuously present object contributes to the detection of sequential regularity violation.


Assuntos
Encéfalo/fisiologia , Percepção de Cores/fisiologia , Potenciais Evocados Visuais/fisiologia , Mãos/fisiologia , Movimento , Orientação/fisiologia , Percepção Visual/fisiologia , Adaptação Fisiológica , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Desempenho Psicomotor , Tempo de Reação , Adulto Jovem
11.
J Dent Educ ; 84(6): 688-694, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32077503

RESUMO

OBJECTIVE: The purpose of this study was to determine if there is an association between Perceptual Ability Test (PAT) results and color vision deficiency (CVD). METHODS: Three consecutive classes of first-year dental students (n = 291) voluntarily participated in the study. The Farnsworth-Munsell 100 Hue Color Vision test (FM-100) was administered to students beneath a Macbeth Judge II viewing booth that provided ideal lighting conditions to ascertain CVD. Results of FM-100 test were recorded as total error scores (TES). Color acuity was scored as superior (TES 0-16), average (TES 20-100), or poor (TES > 100). Additional information of age, sex, ethnicity, and time to complete the FM-100 was obtained. Multiple linear regression was used to determine the association between PAT and CVD while adjusting for age, sex, ethnicity, and time to complete the FM-100 test. RESULTS: TES ranged from 0-244. There were 132 students with superior color acuity, 161 with average, and eight with poor acuity. Females performed better than males on the FM-100 test. Time to complete the FM-100 test ranged from 3:40 minutes to 25:12 minutes. There was a strong relationship between PAT scores and CVD (P = 0.0003). A 1-unit increase in PAT scores was found to result in a 9% decrease in TES; indicating that students with higher PAT scores are less likely to have CVD. CONCLUSION: The PAT may be a preliminary screening instrument to identify students who may have CVD. The FM-100 test can then confirm the presence of CVD. Students with CVD may desire to improve dental shade matching skills through targeted training and education.


Assuntos
Defeitos da Visão Cromática , Visão de Cores , Cor , Percepção de Cores , Testes de Percepção de Cores , Feminino , Humanos , Masculino
12.
Curr Biol ; 30(2): R78-R81, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31962082

RESUMO

A new study shows that the synaptically interconnected axon terminals of colour-sensitive fly photoreceptors that sample the same point in visual space receive additional inhibition from surrounding units; the resulting additional chromatic comparisons result in an optimal decorrelation of photoreceptor inputs. There are striking parallels between newly identified horizontal interactions and those mediated by mammalian horizontal cells.


Assuntos
Visão de Cores , Animais , Cor , Percepção de Cores , Drosophila
13.
Sci Rep ; 10(1): 1236, 2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988305

RESUMO

Animal colouration is often a trade-off between background matching for camouflage from predators, and conspicuousness for communication with con- or heterospecifics. Stomatopods are marine crustaceans known to use colour signals during courtship and contests, while their overall body colouration may provide camouflage. However, we have little understanding of how stomatopods perceive these signals in their environment or whether overall body coloration does provide camouflage from predators. Neogonodactylus oerstedii assess meral spot colour during contests, and meral spot colour varies depending on local habitat. By calculating quantum catch for N. oerstedii's 12 photoreceptors associated with chromatic vision, we found that variation in meral spot total reflectance does not function to increase signal contrast in the local habitat. Neogonodactylus oerstedii also show between-habitat variation in dorsal body colouration. We used visual models to predict a trichromatic fish predator's perception of these colour variations. Our results suggest that sandy and green stomatopods are camouflaged from a typical fish predator in rubble fields and seagrass beds, respectively. To our knowledge, this is the first study to investigate signal contrast and camouflage in a stomatopod. These results provide new insight into the function and evolution of colouration in a species with a complex visual system.


Assuntos
Mimetismo Biológico/fisiologia , Decápodes/fisiologia , Pigmentação/fisiologia , Animais , Percepção de Cores/fisiologia , Crustáceos , Decápodes/genética , Evolução Molecular , Olho/anatomia & histologia , Variação Genética , Células Fotorreceptoras/fisiologia , Filogenia , Pigmentos Biológicos/fisiologia
14.
PLoS One ; 15(1): e0219725, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999697

RESUMO

Evidence from neuroimaging and brain stimulation studies suggest that visual information about objects in the periphery is fed back to foveal retinotopic cortex in a separate representation that is essential for peripheral perception. The characteristics of this phenomenon have important theoretical implications for the role fovea-specific feedback might play in perception. In this work, we employed a recently developed behavioral paradigm to explore whether late disruption to central visual space impaired perception of color. In the first experiment, participants performed a shape discrimination task on colored novel objects in the periphery while fixating centrally. Consistent with the results from previous work, a visual distractor presented at fixation ~100ms after presentation of the peripheral stimuli impaired sensitivity to differences in peripheral shapes more than a visual distractor presented at other stimulus onset asynchronies. In a second experiment, participants performed a color discrimination task on the same colored objects. In a third experiment, we further tested for this foveal distractor effect with stimuli restricted to a low-level feature by using homogenous color patches. These two latter experiments resulted in a similar pattern of behavior: a central distractor presented at the critical stimulus onset asynchrony impaired sensitivity to peripheral color differences, but, importantly, the magnitude of the effect was stronger when peripheral objects contained complex shape information. These results show a behavioral effect consistent with disrupting feedback to the fovea, in line with the foveal feedback suggested by previous neuroimaging studies.


Assuntos
Percepção de Cores/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Campos Visuais/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Cor , Retroalimentação Fisiológica , Feminino , Fóvea Central/fisiologia , Humanos , Masculino , Estimulação Luminosa , Córtex Visual/fisiologia
15.
Behav Processes ; 172: 104043, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31953131

RESUMO

Waiting for the right moment to strike, avoiding the ingestion of harmful foods, or ignoring stimuli associated with ephemeral or depleted resources requires the inhibition of prepotent responses. Good response inhibition facilities flexibility in behaviour which is associated with survival in unpredictable environments. To investigate differences in behavioural flexibility in lizards, we tested reversal learning in the sleepy lizard (Tiliqua rugosa asper) and compared its performance to the relatively closely related eastern blue-tongue skink (Tiliqua scincoides scincoides). We presented both species with a choice between either a light and dark blue stimulus or a triangle and X shape. Both species were able to learn to discriminate between these stimuli and showed similar learning ability during the acquisition of the discrimination. Sleepy lizards, however, demonstrated a higher probability of making a correct choice at the start of the reversal, hinting towards enhanced stimulus response inhibition. Sleepy lizards and blue-tongue skinks inhabit different environments and show differences in ecology and sociobiology, all of which could possibly lead to adaptive specialisation in cognitive ability. Although further research is required, we propose that selection might have led to a change in stimulus response inhibition in the arid-adapted sleepy lizard, because better response inhibition may help them avoid the costs of repeated choices towards stimuli which no longer predict a beneficial outcome.


Assuntos
Ecologia , Inibição Psicológica , Lagartos/fisiologia , Reversão de Aprendizagem , Sociobiologia , Animais , Comportamento de Escolha , Percepção de Cores , Percepção de Forma , Aprendizagem , Especificidade da Espécie
16.
Anim Cogn ; 23(2): 405-414, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31915949

RESUMO

The ability of ungulates to discriminate among vegetation patches depends largely on the senses of vision, olfaction, tactility, and gustation. However, little is known about how ungulates rely on the respective senses in response to varying distances to discrimination targets. This study aimed to assess how cattle discriminate between patches of green and dead forages by means of senses, with a particular attention to the role of vision in relation to the distance to the forages. Thirteen Japanese Black cows were allowed to choose between the two forages from a distance of about 1 m without (- BF) or with (+ BF) a blindfold. The green forage differed from the dead forage in color, texture, odor, quality, and animals' preference. Cows located and ate the green forage as the first choice (Type 1), or as the second choice after touching (Type 2) or further biting (Type 3) the dead forage in error. Overall, the proportion of [Type 1]/[Types 1 + 2 + 3] was above the chance for both - BF and + BF with a decrease by blindfolding. The proportion of [Type 2]/[Types 2 + 3] was above the chance for both - BF and + BF with no effect of blindfolding. The results indicate that cattle discriminating green forage against dead forage rely greatly on vision and to a lesser degree on olfaction when away from the forages, but rely no longer on vision and at least on tactility on the muzzle or in the mouth when in contact with a wrong choice.


Assuntos
Ração Animal , Percepção de Cores , Comportamento Alimentar , Animais , Bovinos , Cor , Feminino , Cabeça , Movimento , Sensação
17.
J Exp Psychol Gen ; 149(1): 1-30, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31107043

RESUMO

What is the unit of visual working memory? This is a question fundamental to our understanding of how the human mind represents the visual world. Here, I challenge the "object-based" account and argue that the unit of visual working memory is better defined by the concept of a "Boolean map." A Boolean map emphasizes the critical role of spatial structure and has been used to characterize the conscious access in attentional processing. Experiments 1-3 show that, for both overall capacity and access to stored information, there is a 0 same-object advantage for different-part features but a significant same-Boolean-map advantage for multiple same-feature objects. Experiments 4-9 support that multiple orientations, but not multiple colors or shapes, can be memorized together as a "spatial structure," and this uniqueness of orientations is attributed to a mimicking strategy (i.e., using the spatial structure of Boolean map to mimic the feature orientation). In summary, a Boolean map offers a better account for the unit of visual working memory than an object does. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Atenção/fisiologia , Memória de Curto Prazo/fisiologia , Estimulação Luminosa/métodos , Cor , Percepção de Cores , Humanos , Orientação Espacial
18.
J Prosthet Dent ; 123(2): 322-329, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31227232

RESUMO

STATEMENT OF PROBLEM: Whether intraoral digital scanners with an integrated shade-taking function can substitute for colorimeters, spectrophotometers, or the visual method to reduce working time is unclear. PURPOSE: The purpose of this clinical study was to evaluate the accuracy of the measurement of tooth shade obtained with an intraoral digital scanner in vivo. MATERIAL AND METHODS: Shades of 120 maxillary anterior teeth were evaluated by using a SpectroShade spectrophotometer (SS) and a TRIOS 3 intraoral digital scanner (T3) on 20 participants. The matching of shade readings between the T3 and SS was used to estimate the accuracy of the T3. The percentage of readings when a difference between the shades obtained by both devices was visually perceptible (ΔE>3.7) was calculated. Each of the 120 teeth was measured 5 times to assess repeatability. RESULTS: The accuracy of the T3 was 53.3% when the color was recorded as a Vita 3D-Master (VM) shade and 27.5% for the Vita Classical (VC) shade guide when the SS was taken as a reference. A visually perceptible color difference was found in 25% (VM) and 50.8% (VC) of situations when the shade was determined with the SS and 48.3% (VM) and 78.3% (VC) with the T3. Repeatability was 92% (VM) and 93.5% (VC) for the SS, and 90.33% (VM) and 87.17% (VC) for the T3. CONCLUSIONS: The findings of this study revealed that the tooth color determined by the T3 does not exactly match that obtained by the SS that additional methods of measuring tooth color are recommended. The accuracy of the T3 was higher when the color was recorded as VM values rather than VC values.


Assuntos
Pigmentação em Prótese , Dente , Cor , Percepção de Cores , Espectrofotometria
19.
Acta Psychol (Amst) ; 202: 102978, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31790912

RESUMO

Since the ordinal position effect was identified, several studies have investigated its mechanism in various contexts; however, how the space location of ordinal symbols influences this effect remains unclear. Thus, the present study explored Chinese words representing the day before yesterday, yesterday, tomorrow, and the day after tomorrow as ordinal symbols to investigate how the stimulus space location influences the ordinal position effect across different task contexts. We randomly and equally presented days on the left or right location of a display and asked participants to perform a stimulus space location, a stimulus colour and a stimulus order classification task in three consecutive experiments, respectively. The results revealed that the spatial stimulus-response compatibility effect and Simon effect prevailed in the stimulus space location and colour classification task. Conversely, the ordinal position effect prevailed in the stimulus order classification task. These results suggested that (1) the spatial stimulus-response compatibility effect (or Simon effect) and the ordinal position effect cannot appear simultaneously in some experimental contexts and that (2) the task context predicted which of these effects prevailed. From these results, we conclude that the ordinal symbols could be coded depending on multiple reference frames, including spatial and non-spatial reference frame, and the use of the reference frame was mediated by the task context.


Assuntos
Percepção de Cores/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Percepção Espacial/fisiologia , Adulto , Feminino , Humanos , Masculino , Distribuição Aleatória , Adulto Jovem
20.
Vision Res ; 166: 33-42, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841707

RESUMO

The purpose of the present study was to assess the accommodative response and pupillary dynamics while reading passages with different text-background color combinations on an LCD screen. Twenty healthy young adults read fourteen 2-min passages designed with fourteen different color combinations between text and background, while the accommodative and pupil responses were continuously measured with a binocular open-field autorefractometer. Our results revealed that the text-background color combination modulates the accommodative and pupillary dynamics during a 2-minutes reading task. The blue-red combination induced a heightened accommodative response, whereas positive polarities were associated with more variability of the accommodative response and smaller pupil sizes. Participants reported lower perceived ratings of legibility for text-background color combination with lower luminance contrast (white-yellow). The manipulation of text-background color did not have a significant effect on reading speed. These results may have important applications in the design of digital visual interfaces.


Assuntos
Acomodação Ocular/fisiologia , Percepção de Cores/fisiologia , Sensibilidades de Contraste/fisiologia , Pupila/fisiologia , Leitura , Adulto , Feminino , Humanos , Luz , Masculino , Adulto Jovem
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