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1.
PLoS One ; 15(12): e0238554, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382696

RESUMO

Previous work has shown that symmetrical stimuli are judged as lasting longer than asymmetrical ones, even when actual duration is matched. This effect has been replicated with different methods and stimuli types. We aimed to a) replicate the effect of symmetry on subjective duration, and b) assess whether it was further modulated by the number of symmetrical axes. There was no evidence for either effect. This null result cannot be explained by reduced statistical power or enhanced floor or ceiling effects. There is no obvious stimulus-based explanation either. However, we are mindful of the reproducibility crisis and file drawer problems in psychology. Other symmetry and time perception researchers should be aware of this null result. One possibility is that the effect of symmetry on subjective duration is limited to very specific experimental paradigms.


Assuntos
Percepção de Forma/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção do Tempo/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicofísica , Reprodutibilidade dos Testes , Visão Ocular/fisiologia
2.
PLoS One ; 15(9): e0238976, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925930

RESUMO

The use of pictures as experimental stimuli is a frequent practice in psychological and educational research. In addition, picture-naming task allows the study of different cognitive processes such as perception, attention, memory and language. Line drawings have been widely used in research to date but it has begun to be highlighted the need for more ecological stimuli such as photographs. However, normative data of a photographic set has not been published yet for use with children. We present PicPsy, a new standardized bank of photographs and matched line drawing. We collected written picture-naming norms for name agreement, unknown responses, alternative names, familiarity and visual complexity. A total of 118 native Spanish-speaking children in grades 3-4 participated in the study. For comparison purposes, 89 adults were also included in the study. Child and adult performance was highly correlated, but we found significant age group differences in all variables examined except for visual complexity. Researchers and teachers could benefit from using the new standardized bank reported here which is published under public domain license. The data and materials for this research are available at the Open Science Framework, https://osf.io/nyf3t/.


Assuntos
Nomes , Reconhecimento Visual de Modelos/classificação , Adolescente , Criança , Pré-Escolar , Bases de Dados Factuais , Feminino , Percepção de Forma/fisiologia , Humanos , Idioma , Desenvolvimento da Linguagem , Masculino , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico , Traduções , Percepção Visual/fisiologia , Redação
3.
PLoS One ; 15(9): e0238378, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32898184

RESUMO

Current research examined the differential effects of pills' shape (angular vs. curvy) on the perceived efficacy of the medicine, evoked bodily sensations and emotions. We investigated these effects by using different types of angular vs. curved stimuli: abstract drawn shapes (Study 1), 3D-printed mockup pills (Study 2) and photographs of the existing pills (Study 3). Participants were asked to imagine 'taking' angular and curved pills. They had to focus on the bodily sensations and report the evoked activations/deactivations in different body parts. Across three studies, we found that the angular pills evoke overall more activations in the body compared to curvy pills. We further reported differences in the topography of angular vs. curved pills'-triggered sensations in different body parts. Our results also revealed that angularity is linked with an energizing effect while roundness is associated with a calming effect. The shape effects were demonstrated not only in self-reported energized vs. calm subjective feelings but also in performance on a timed cognitive test. Compared to incongruent designs, pill designs (angular vs. curved) congruent with proposed drug benefits (energizing vs. calming) were perceived as more effective. Moreover, we found differences in emotions triggered by pills of different shapes. The present research provided new findings on angularity vs. curvature perception that may be valuable for cognitive psychology, marketing, pharmaceutical and supplements industry, and other applied fields.


Assuntos
Emoções/fisiologia , Potenciais Evocados/fisiologia , Percepção de Forma/fisiologia , Sensação/fisiologia , Comprimidos/química , Adolescente , Adulto , Feminino , Humanos , Masculino , Autorrelato , Comprimidos/administração & dosagem , Adulto Jovem
4.
PLoS One ; 15(8): e0224471, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797090

RESUMO

We present normative data for an expanded set of stimuli designed to investigate past experience effects on object detection. The stimuli are vertically-elongated "bipartite" displays comprising two equal-area regions meeting at an articulated central border. When the central border is assigned to one side, a shaped figure (i.e., an object) is detected on that side. Participants viewing brief masked exposures typically detect figures more often on the critical side of Intact displays where a common ("familiar") object is depicted than on a matched critical side of Part-Rearranged (PR) displays comprising the same parts arranged in novel configurations. This pattern of results showed that past experience in the form of familiar configuration rather than familiar parts is a prior for figure assignment. Spurred by research implicating a network involving the perirhinal cortex of the medial temporal lobe in these familiar configuration effects, we enlarged the stimulus set from 24 to 48 base stimuli to increase its usefulness for behavioral, neuropsychological, and neuroimaging experiments. We measured the percentage of participants who agreed on a single interpretation for each side of Intact, Upright PR, and Inverted PR displays (144 displays; 288 sides) under long exposure conditions. High inter-subject agreement is taken to operationally define a familiar configuration. This new stimulus set is well-suited to investigate questions concerning how parts and wholes are integrated and how high- and low-level brain areas interact in object detection. This set also allows tests of predictions regarding cross-border competition in figure assignment and assessments of individual differences. The displays, their image statistics, and normative data are available online (https://osf.io/j9kz2/).


Assuntos
Percepção de Forma/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Visual/fisiologia , Adulto , Encéfalo , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Estimulação Luminosa/métodos , Reconhecimento Psicológico , Lobo Temporal
5.
J Vis ; 20(6): 8, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32531062

RESUMO

It is well known that priming, probably by the contents of working memory, can influence subsequent visual task performance. How ubiquitous is this effect? Can incidental exposure to visual stimuli influence the deployment of attention when there is no explicit visual task? Results of two experiments show that a preceding stimulus can influence free-viewing eye movements. A simple change detection task was used as the cover task. The initial memory display was the priming display, while subsequent filler display constituted the free-viewing display of our interest. In Experiment 1, subjects were asked to memorize the number of items in the priming display. Subjects were not explicitly instructed to attend to features, but these might still be implicitly encoded. In Experiment 2, a more complex change detection task required subjects to memorize the number, color, and shape of priming items. Here, prime features were attended and, presumably, explicitly encoded. We were interested to know whether incidentally or explicitly encoded features of prime items would influence attention distribution in the filler display. In both experiments, items sharing color and shape with the prime were attended more often than predicted by chance. Items sharing neither color nor shape were attended less often. Items sharing either color or shape (not both) could also attract attention showing that the priming need not be based on a bound representation of the primed item. Effects were stronger in Experiment 2. No intention or top-down control appears to be needed to produce this priming.


Assuntos
Atenção/fisiologia , Percepção de Cores/fisiologia , Percepção de Forma/fisiologia , Memória de Curto Prazo/fisiologia , Adulto , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Detecção de Sinal Psicológico , Análise e Desempenho de Tarefas
6.
J Vis ; 20(6): 17, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32579672

RESUMO

Prior knowledge can help observers in various situations. Adults can simultaneously learn two location priors and integrate these with sensory information to locate hidden objects. Importantly, observers weight prior and sensory (likelihood) information differently depending on their respective reliabilities, in line with principles of Bayesian inference. Yet, there is limited evidence that observers actually perform Bayesian inference, rather than a heuristic, such as forming a look-up table. To distinguish these possibilities, we ask whether previously learned priors will be immediately integrated with a new, untrained likelihood. If observers use Bayesian principles, they should immediately put less weight on the new, less reliable, likelihood ("Bayesian transfer"). In an initial experiment, observers estimated the position of a hidden target, drawn from one of two distinct distributions, using sensory and prior information. The sensory cue consisted of dots drawn from a Gaussian distribution centered on the true location with either low, medium, or high variance; the latter introduced after block three of five to test for evidence of Bayesian transfer. Observers did not weight the cue (relative to the prior) significantly less in the high compared to medium variance condition, counter to Bayesian predictions. However, when explicitly informed of the different prior variabilities, observers placed less weight on the new high variance likelihood ("Bayesian transfer"), yet, substantially diverged from ideal. Much of this divergence can be captured by a model that weights sensory information, according only to internal noise in using the cue. These results emphasize the limits of Bayesian models in complex tasks.


Assuntos
Teorema de Bayes , Percepção de Forma/fisiologia , Percepção Espacial/fisiologia , Adolescente , Adulto , Feminino , Heurística , Humanos , Aprendizagem , Masculino , Distribuição Normal , Probabilidade , Adulto Jovem
7.
Proc Natl Acad Sci U S A ; 117(26): 14873-14882, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32532920

RESUMO

Arguably the most foundational principle in perception research is that our experience of the world goes beyond the retinal image; we perceive the distal environment itself, not the proximal stimulation it causes. Shape may be the paradigm case of such "unconscious inference": When a coin is rotated in depth, we infer the circular object it truly is, discarding the perspectival ellipse projected on our eyes. But is this really the fate of such perspectival shapes? Or does a tilted coin retain an elliptical appearance even when we know it's circular? This question has generated heated debate from Locke and Hume to the present; but whereas extant arguments rely primarily on introspection, this problem is also open to empirical test. If tilted coins bear a representational similarity to elliptical objects, then a circular coin should, when rotated, impair search for a distal ellipse. Here, nine experiments demonstrate that this is so, suggesting that perspectival shapes persist in the mind far longer than traditionally assumed. Subjects saw search arrays of three-dimensional "coins," and simply had to locate a distally elliptical coin. Surprisingly, rotated circular coins slowed search for elliptical targets, even when subjects clearly knew the rotated coins were circular. This pattern arose with static and dynamic cues, couldn't be explained by strategic responding or unfamiliarity, generalized across shape classes, and occurred even with sustained viewing. Finally, these effects extended beyond artificial displays to real-world objects viewed in naturalistic, full-cue conditions. We conclude that objects have a remarkably persistent dual character: their objective shape "out there," and their perspectival shape "from here."


Assuntos
Percepção de Profundidade/fisiologia , Percepção de Forma/fisiologia , Sinais (Psicologia) , Humanos , Filosofia , Rotação
8.
J Vis ; 20(6): 2, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32492099

RESUMO

Object shape is an important cue to material identity and for the estimation of material properties. Shape features can affect material perception at different levels: at a microscale (surface roughness), mesoscale (textures and local object shape), or megascale (global object shape) level. Examples for local shape features include ripples in drapery, clots in viscous liquids, or spiraling creases in twisted objects. Here, we set out to test the role of such shape features on judgments of material properties softness and weight. For this, we created a large number of novel stimuli with varying surface shape features. We show that those features have distinct effects on softness and weight ratings depending on their type, as well as amplitude and frequency, for example, increasing numbers and pointedness of spikes makes objects appear harder and heavier. By also asking participants to name familiar objects, materials, and transformations they associate with our stimuli, we can show that softness and weight judgments do not merely follow from semantic associations between particular stimuli and real-world object shapes. Rather, softness and weight are estimated from surface shape, presumably based on learned heuristics about the relationship between a particular expression of surface features and material properties. In line with this, we show that correlations between perceived softness or weight and surface curvature vary depending on the type of surface feature. We conclude that local shape features have to be considered when testing the effects of shape on the perception of material properties such as softness and weight.


Assuntos
Percepção de Forma/fisiologia , Manufaturas , Percepção do Tato/fisiologia , Adulto , Feminino , Humanos , Julgamento , Masculino , Adulto Jovem
9.
J Vis ; 20(6): 5, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32511666

RESUMO

Perceptual learning (PL), often characterized by improvements in perceptual performance with training that are specific to the stimulus conditions used during training, exemplifies experience-dependent cortical plasticity. An improved understanding of how neuromodulatory systems shape PL promises to provide new insights into the mechanisms of plasticity, and by extension how PL can be generated and applied most efficiently. Previous studies have reported enhanced PL in human subjects following administration of drugs that increase signaling through acetylcholine (ACh) receptors, and physiological evidence indicates that ACh sharpens neuronal selectivity, suggesting that this neuromodulator supports PL and its stimulus specificity. Here we explored the effects of enhancing endogenous cholinergic signaling during PL of a visual texture discrimination task. We found that training on this task in the lower visual field yielded significant behavioral improvement at the trained location. However, a single dose of the cholinesterase inhibitor donepezil, administered before training, did not significantly impact either the magnitude or the location specificity of texture discrimination learning compared with placebo. We discuss potential explanations for discrepant findings in the literature regarding the role of ACh in visual PL, including possible differences in plasticity mechanisms in the dorsal and ventral cortical processing streams.


Assuntos
Inibidores da Colinesterase/farmacologia , Donepezila/farmacologia , Percepção de Forma/efeitos dos fármacos , Aprendizagem/efeitos dos fármacos , Percepção Visual/efeitos dos fármacos , Adulto , Aprendizagem por Discriminação/fisiologia , Discriminação Psicológica , Feminino , Percepção de Forma/fisiologia , Humanos , Aprendizagem/fisiologia , Masculino , Campos Visuais , Percepção Visual/fisiologia , Adulto Jovem
10.
J Neurosci ; 40(27): 5283-5299, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32467356

RESUMO

Human scene categorization is characterized by its remarkable speed. While many visual and conceptual features have been linked to this ability, significant correlations exist between feature spaces, impeding our ability to determine their relative contributions to scene categorization. Here, we used a whitening transformation to decorrelate a variety of visual and conceptual features and assess the time course of their unique contributions to scene categorization. Participants (both sexes) viewed 2250 full-color scene images drawn from 30 different scene categories while having their brain activity measured through 256-channel EEG. We examined the variance explained at each electrode and time point of visual event-related potential (vERP) data from nine different whitened encoding models. These ranged from low-level features obtained from filter outputs to high-level conceptual features requiring human annotation. The amount of category information in the vERPs was assessed through multivariate decoding methods. Behavioral similarity measures were obtained in separate crowdsourced experiments. We found that all nine models together contributed 78% of the variance of human scene similarity assessments and were within the noise ceiling of the vERP data. Low-level models explained earlier vERP variability (88 ms after image onset), whereas high-level models explained later variance (169 ms). Critically, only high-level models shared vERP variability with behavior. Together, these results suggest that scene categorization is primarily a high-level process, but reliant on previously extracted low-level features.SIGNIFICANCE STATEMENT In a single fixation, we glean enough information to describe a general scene category. Many types of features are associated with scene categories, ranging from low-level properties, such as colors and contours, to high-level properties, such as objects and attributes. Because these properties are correlated, it is difficult to understand each property's unique contributions to scene categorization. This work uses a whitening transformation to remove the correlations between features and examines the extent to which each feature contributes to visual event-related potentials over time. We found that low-level visual features contributed first but were not correlated with categorization behavior. High-level features followed 80 ms later, providing key insights into how the brain makes sense of a complex visual world.


Assuntos
Percepção de Forma/fisiologia , Percepção Visual/fisiologia , Adolescente , Encéfalo/fisiologia , Cor , Eletroencefalografia , Potenciais Evocados Visuais/fisiologia , Feminino , Humanos , Masculino , Processos Mentais/fisiologia , Ruído , Estimulação Luminosa , Análise de Ondaletas , Adulto Jovem
11.
Invest Ophthalmol Vis Sci ; 61(5): 23, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32413126

RESUMO

Purpose: Grouping of flankers from the target can modulate crowding in adults. Visual acuity in children is measured clinically using charts with targets and different flankers to enhance spatial interactions. We investigated grouping effects on interactions using visual acuity letters, flanked by contours and letters, in children. Methods: Visual acuity for isolated and flanked letters was measured in 155 three- to 11-year old children and 32 adults. Flankers were one stroke width from the target and were a box or four bars and black or red letters. Magnitudes of interaction were flanked minus isolated logMAR acuities. Psychometric function slopes were also examined. Results: Magnitudes of interaction by contours did not change significantly with age. They were 0.047 ± 0.014 logMAR more with bars than a box. Interaction from flanking letters reduced with age, adults being not different from 9- to 11-year-olds for black and red letter surrounds. It was weaker by 0.033 ± 0.013 logMAR when a black letter was surrounded by red rather than black letters. Psychometric function slopes for visual acuity were steepest for the youngest children (3-5 years). Conclusions: For contour and letter flankers, grouping effects on interaction magnitude are age independent. Grouping bars into a box forming a single object reduces magnitude of effect. Grouping letter flankers by color and ungrouping them from the target reduce interaction magnitude by ∼8%, suggesting that luminance-defined form dominates. Differently colored letter flankers of high-luminance contrast on acuity charts could draw attention to the target but retain significant interaction strength.


Assuntos
Fóvea Central/fisiologia , Processamento Espacial/fisiologia , Acuidade Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Sensibilidades de Contraste/fisiologia , Aglomeração , Feminino , Percepção de Forma/fisiologia , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Psicometria
12.
Proc Natl Acad Sci U S A ; 117(21): 11735-11743, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32414926

RESUMO

Three-dimensional (3D) shape perception is one of the most important functions of vision. It is crucial for many tasks, from object recognition to tool use, and yet how the brain represents shape remains poorly understood. Most theories focus on purely geometrical computations (e.g., estimating depths, curvatures, symmetries). Here, however, we find that shape perception also involves sophisticated inferences that parse shapes into features with distinct causal origins. Inspired by marble sculptures such as Strazza's The Veiled Virgin (1850), which vividly depict figures swathed in cloth, we created composite shapes by wrapping unfamiliar forms in textile, so that the observable surface relief was the result of complex interactions between the underlying object and overlying fabric. Making sense of such structures requires segmenting the shape based on their causes, to distinguish whether lumps and ridges are due to the shrouded object or to the ripples and folds of the overlying cloth. Three-dimensional scans of the objects with and without the textile provided ground-truth measures of the true physical surface reliefs, against which observers' judgments could be compared. In a virtual painting task, participants indicated which surface ridges appeared to be caused by the hidden object and which were due to the drapery. In another experiment, participants indicated the perceived depth profile of both surface layers. Their responses reveal that they can robustly distinguish features belonging to the textile from those due to the underlying object. Together, these findings reveal the operation of visual shape-segmentation processes that parse shapes based on their causal origin.


Assuntos
Percepção de Forma/fisiologia , Escultura , Percepção Visual/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Máquina de Vetores de Suporte , Propriedades de Superfície , Análise e Desempenho de Tarefas , Têxteis
13.
Invest Ophthalmol Vis Sci ; 61(4): 12, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32293665

RESUMO

Purpose: There is little research evidence to explain why older adults have more problems adapting to new spectacles incorporating astigmatic changes than younger adults. We tested the hypothesis that astigmatic lenses oriented obliquely would lead to errors in verticality perception that are greater for older than younger adults. Methods: Participants included 12 young (mean ± SD age 25.1 ± 5.0 years) and 12 older (70.2 ± 6.3 years) adults with normal vision. Verticality perception was assessed using a computer-based subjective visual vertical (SVV) task, under static and dynamic (in the presence of a moving peripheral distractor) conditions and when viewing targets through the near refractive correction (control condition), and two forms of astigmatic lenses oriented in the vertical, horizontal, and oblique meridians. Results: The older group demonstrated much greater dynamic SVV errors (e.g., 3.4° for the control condition) than the younger group (1.2°, P = 0.002), larger errors with vertical and horizontal astigmatic lenses (older group 4.1°and 5.2° for toric and magnifier lenses vs. younger group 1.2° and 1.4°, respectively, P < 0.001), and a larger influence of the oblique astigmatic lenses (older group 5.6° vs. younger group 2.1°, P<0.001). Conclusions: Astigmatic lenses produced little or no errors in SVV in young adults, but large static and dynamic SVV errors in older adults. This indicates a greater reliance on visual input with increased age for SVV, and helps explain why oblique astigmatic refractive corrections can cause dizziness in older patients and why they report greater difficulties adapting to new spectacles with astigmatic changes.


Assuntos
Astigmatismo/fisiopatologia , Percepção de Forma/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Humanos , Pessoa de Meia-Idade , Testes Visuais , Acuidade Visual , Adulto Jovem
14.
Sci Rep ; 10(1): 5821, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242057

RESUMO

Object memories activated by borders serve as priors for figure assignment: figures are more likely to be perceived on the side of a border where a well-known object is sketched. Do object memories also affect the appearance of object borders? Memories represent past experience with objects; memories of well-known objects include many with sharp borders because they are often fixated. We investigated whether object memories affect appearance by testing whether blurry borders appear sharper when they are contours of well-known objects versus matched novel objects. Participants viewed blurry versions of one familiar and one novel stimulus simultaneously for 180 ms; then made comparative (Exp. 1) or equality judgments regarding perceived blur (Exps. 2-4). For equivalent levels of blur, the borders of well-known objects appeared sharper than those of novel objects. These results extend evidence for the influence of past experience to object appearance, consistent with dynamic interactive models of perception.


Assuntos
Percepção de Forma/fisiologia , Memória/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Feminino , Humanos , Julgamento/fisiologia , Masculino , Estimulação Luminosa/métodos
15.
PLoS One ; 15(4): e0230913, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330136

RESUMO

Object permanence has been investigated with a variety of paradigms and measures, yielding heterogeneous findings. The current study employed a novel Violation-of-Expectation paradigm measuring pupil dilation as indicator of cognitive effort and surprise. Across repeated trials, infants watched videos of animated toys either stopping in an open door frame or moving across the open door frame off screen. The door then closed and opened up again to reveal either the toy, or an empty space. In Experiment 1, 18-month-olds's pupils dilated in response to the unexpected empty outcome more than to the expected empty outcome, establishing the paradigm as a suitable measure of violation of object expectation. Using the same paradigm, Experiment 2 revealed an absence of this object expectation effect for 10-month-olds. Results are discussed with regard to paradigmatic aspects and developmental differences. It is suggested that young infants do not automatically represent occluded objects upon perceiving occlusion events, and that occlusion events may initially require relevance in terms of individual activity or social interaction.


Assuntos
Percepção de Forma/fisiologia , Pupila/fisiologia , Feminino , Humanos , Lactente , Masculino
16.
Atten Percept Psychophys ; 82(2): 426-456, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32133598

RESUMO

The mechanisms guiding visual attention are of great interest within cognitive and perceptual psychology. Many researchers have proposed models of these mechanisms, which serve to both formalize their theories and to guide further empirical investigations. The assumption that a number of basic features are processed in parallel early in the attentional process is common among most models of visual attention and visual search. To date, much of the evidence for parallel processing has been limited to set-size manipulations. Unfortunately, set-size manipulations have been shown to be insufficient evidence for parallel processing. We applied Systems Factorial Technology, a general nonparametric framework, to test this assumption, specifically whether color and shape are processed in parallel or in serial, in three experiments representative of feature search, conjunctive search, and odd-one-out search, respectively. Our results provide strong evidence that color and shape information guides search through parallel processes. Furthermore, we found evidence for facilitation between color and shape when the target was known in advance but performance consistent with unlimited capacity, independent parallel processing in odd-one-out search. These results confirm core assumptions about color and shape feature processing instantiated in most models of visual search and provide more detailed clues about the manner in which color and shape information is combined to guide search.


Assuntos
Percepção de Cores/fisiologia , Percepção de Forma/fisiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Adulto , Atenção/fisiologia , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Distribuição Aleatória , Adulto Jovem
17.
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
18.
J Vis ; 20(2): 7, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32097483

RESUMO

In a reverse-phi stimulus, the contrast luminance of moving dots is reversed each displacement step. Under those conditions, the direction of the moving dots is perceived in the direction opposite of the displacement direction of the dots. In this study, we investigate if mice respond oppositely to phi and reverse-phi stimuli. Mice ran head-fixed on a Styrofoam ball floating on pressurized air at the center of a large dome. We projected random dot patterns that were displaced rightward or leftward, using either a phi or a reverse-phi stimulus. For phi stimuli, changes in direction caused the mice to reflexively compensate and adjust their running direction in the direction of the displaced pattern. We show that for reverse-phi stimuli mice compensate in the direction opposite to the displacement direction of the dots, in accordance with the perceived direction of displacement in humans for reverse-phi stimuli.


Assuntos
Percepção de Forma/fisiologia , Locomoção/fisiologia , Percepção de Movimento/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Reflexo Vestíbulo-Ocular/fisiologia , Animais , Discriminação Psicológica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estimulação Luminosa
19.
J Vis ; 20(2): 10, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32097486

RESUMO

Adults can rapidly recognize material properties in natural images, and children's performance in material categorization tasks suggests that this ability develops slowly during childhood. In the current study, we further examined the information children use to recognize materials during development by asking how the use of local versus global visual features for material perception changes in middle childhood. We recruited adults and 5- to 10-year-old children for three experiments that required participants to distinguish between shape-matched images of real and artificial food. Accurate performance in this task requires participants to distinguish between a wide range of material properties characteristic of each category, thus testing material perception abilities broadly. In two tasks, we applied distinct methods of image scrambling (block scrambling and diffeomorphic scrambling) to parametrically disrupt global appearance while preserving features in small spatial neighborhoods. In the third task, we used image blurring to parametrically disrupt local feature visibility. Our key question was whether or not participant age affected performance differently when local versus global appearance was disrupted. We found that although image blur led to disproportionately poorer performance in young children, this effect was reduced or absent when diffeomorphic scrambling was used. We interpret this outcome as evidence that the ability to recruit large-scale visual features for material perception may develop slowly during middle childhood.


Assuntos
Cognição/fisiologia , Percepção de Forma/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adulto , Criança , Desenvolvimento Infantil , Pré-Escolar , Comportamento de Escolha , Feminino , Humanos , Masculino , Adulto Jovem
20.
J Vis ; 20(2): 1, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32040160

RESUMO

Binocular disparity signals allow for the estimation of three-dimensional shape, even in the absence of monocular depth cues. The perception of such disparity-defined form depends, however, on the linkage of multiple disparity measurements over space. Performance limitations in cyclopean tasks thus inform us about errors arising in disparity measurement and difficulties in the linkage of such measurements. We used a cyclopean orientation discrimination task to examine the perception of disparity-defined form. Participants were presented with random-dot sinusoidal modulations in depth and asked to report whether they were clockwise or counter-clockwise rotated. To assess the effect of different noise structures on measurement and linkage processes, task performance was measured in the presence of binocular, random-dot masks, structured as either antiphase depth sinusoids, or as random distributions of dots in depth. For a fixed number of surface dots, the ratio of mask-to-surface dots was varied to obtain thresholds for orientation discrimination. Antiphase masks were found to be more effective than random depth masks, requiring a lower mask-to-surface dot ratio to inhibit performance. For antiphase masks, performance improved with decreased cyclopean frequency, increased disparity amplitude, and/or an increase in the total number of stimulus dots. Although a cross-correlation model of disparity measurement could account for antiphase mask performance, random depth masking effects were consistent with limitations in relative disparity processing. This suggests that performance is noise-limited for antiphase masks and complexity-limited for random masks. We propose that use of differing mask types may prove effective in understanding these distinct forms of impairment.


Assuntos
Orientação Espacial/fisiologia , Mascaramento Perceptivo/fisiologia , Disparidade Visual/fisiologia , Sinais (Psicologia) , Percepção de Profundidade/fisiologia , Percepção de Forma/fisiologia , Humanos , Imageamento Tridimensional , Visão Binocular
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