Assessing Spontaneous Categorical Processing of Visual Shapes via Frequency-Tagging EEG.

Categorization is an essential cognitive and perceptual process, which happens spontaneously. However, earlier research often neglected the spontaneous nature of this process by mainly adopting explicit tasks in behavioral or neuroimaging paradigms. Here, we use frequency-tagging (FT) during electroencephalography (EEG) in 22 healthy human participants (both male and female) as a direct approach to pinpoint spontaneous visual categorical processing. Starting from schematic natural visual stimuli, we created morph sequences comprising 11 equal steps. Mirroring a behavioral categorical perception discrimination paradigm, we administered a FT-EEG oddball paradigm, assessing neural sensitivity for equally sized differences within and between stimulus categories. Likewise, mirroring a behavioral category classification paradigm, we administered a sweep FT-EEG oddball paradigm, sweeping from one end of the morph sequence to the other, thereby allowing us to objectively pinpoint the neural category boundary. We found that FT-EEG can implicitly measure categorical processing and discrimination. More specifically, we could derive an objective neural index of the required level to differentiate between the two categories, and this neural index showed the typical marker of categorical perception (i.e., stronger discrimination across as compared with within categories). The neural findings of the implicit paradigms were also validated using an explicit behavioral task. These results provide evidence that FT-EEG can be used as an objective tool to measure discrimination and categorization and that the human brain inherently and spontaneously (without any conscious or decisional processes) uses higher-level meaningful categorization information to interpret ambiguous (morph) shapes.

Exploring the Semantic-Inconsistency Effect in Scenes Using a Continuous Measure of Linguistic-Semantic Similarity.

Viewers use contextual information to visually explore complex scenes. Object recognition is facilitated by exploiting object-scene relations (which objects are expected in a given scene) and object-object relations (which objects are expected because of the occurrence of other objects). Semantically inconsistent objects deviate from these expectations, so they tend to capture viewers' attention (the semantic-inconsistency effect). Some objects fit the identity of a scene more or less than others, yet semantic inconsistencies have hitherto been operationalized as binary (consistent vs. inconsistent). In an eye-tracking experiment (N = 21 adults), we study the semantic-inconsistency effect in a continuous manner by using the linguistic-semantic similarity of an object to the scene category and to other objects in the scene. We found that both highly consistent and highly inconsistent objects are viewed more than other objects (U-shaped relationship), revealing that the (in)consistency effect is more than a simple binary classification.

An efficient Bayesian observer model of attractive and repulsive temporal context effects when perceiving multistable dot lattices.

In multistable dot lattices, the orientation we perceive is attracted toward the orientation we perceived in the immediately preceding stimulus and repelled from the orientation for which most evidence was present previously (Van Geert, Moors, Haaf, & Wagemans, 2022). Theoretically-inspired models have been proposed to explain the co-occurrence of attractive and repulsive context effects in multistable dot lattice tasks, but these models artificially induced an influence of the previous trial on the current one without detailing the process underlying such an influence (Gepshtein & Kubovy, 2005; Schwiedrzik et al., 2014). We conducted a simulation study to test whether the observed attractive and repulsive context effects could be explained with an efficient Bayesian observer model (Wei & Stocker, 2015). This model assumes variable encoding precision of orientations in line with their frequency of occurrence (i.e., efficient encoding) and takes the dissimilarity between stimulus space and sensory space into account. An efficient Bayesian observer model including both a stimulus and a perceptual level was needed to explain the co-occurrence of both attractive and repulsive temporal context effects. Furthermore, this model could reproduce the empirically observed strong positive correlation between individuals' attractive and repulsive effects (Van Geert et al., 2022), by assuming a positive correlation between temporal integration constants at the stimulus and the perceptual level. To conclude, the study brings evidence that efficient encoding and likelihood repulsion on the stimulus level can explain the repulsive context effect, whereas perceptual prior attraction can explain the attractive temporal context effect when perceiving multistable dot lattices.

Perceptual grouping in complex rhythmic patterns.

Perception of simple temporal patterns has been shown to rely on accentuations in terms of intensity, pitch, or timbre, but also on grouping according to runs of the same events (intervals between successive sounds or light flashes) or significant gaps between them (Garner in The processing of information and structure. Lawrence Erlbaum, 1974; Preusser et al. in Am J Psychol 83(2):151-170 in 1970; Royer and Garner in Percept Psychophys 1(1):41-47, 1966; Royer and Garner in Percept Psychophys 7(2):115-120, 1970; Yu et al. in Atten Percept Psychophys 77(8):2728-2739, 2015). Here we investigate whether the run and gap principles can also account for participants' perceived start of complex rhythmic patterns. We also investigated the role of participants' musical training. Sixteen novices and 16 amateur musicians listened to rhythmic patterns and indicated perceived starting points by a single tap with a drumstick on electronic pads. Auditory patterns contained prominent gaps, runs, or a combination of the two for target intervals. We systematically varied task complexity in terms of the target durations of intervals constituting the patterns and overall tempos. Overall, run and gap principles proved to be useful grouping principles accounting for a large proportion (59.2%) of the selected starting positions underlining the universal relevance of these principles. Grouping principles were not as successful in predicting the perceived start of a rhythmic pattern compared to previous studies. Results indicate that additional grouping principles must be at play. Predictive power of the grouping principles varied depending on the structure of rhythmic patterns. For rhythmic patterns including longer intervals (i.e., longer gaps) the gap principle alone or in combination with the run principle showed the strongest predictive power. Novices and amateur musicians were similar in their usage of grouping principles suggesting that the underlying principles might be equally at the dispositions of performers and listeners.

Towards the most prägnant Gestalt: Leveling and sharpening as contextually dependent adaptive strategies.

Gestalt psychologists posited that we always organize our visual input in the best way possible under the given conditions. Both weakening or removing unnecessary details (i.e., leveling) and exaggerating distinctive features (i.e., sharpening) can contribute to achieving a better organization. When is a feature leveled or sharpened, however? We investigated whether the importance of a feature for discrimination among alternatives influences which organizational tendency occurs. Participants were simultaneously presented with four figures composed of simple geometrical shapes, and asked to reconstruct one of these figures in such a way that another participant would be able to recognize it among the alternatives. The four figures differed either qualitatively or only quantitatively (i.e., far or close context). Regarding quantitative differences, two feature dimensions were varied, with one manifesting a wider range of variability across the alternatives than the other. In case of a smaller variability range, the target figure was either at the extreme of the range or had an in-between value. As expected, the results indicated that sharpening occurred more often for the feature with an extreme value, for the feature exhibiting more variability, and for the features of figures presented in the close context, than for the feature with a non-extreme value, exhibiting less variability, or in the far context. In line with Metzger's (1941) definition of prägnant Gestalts, the essence of a Gestalt is context-dependent, and this will influence whether leveling or sharpening of a feature will lead to the best organization in the specific context.

Beautification of images by generative adversarial networks.

Finding the properties underlying beauty has always been a prominent yet difficult problem. However, new technological developments have often aided scientific progress by expanding the scientists' toolkit. Currently in the spotlight of cognitive neuroscience and vision science are deep neural networks. In this study, we have used a generative adversarial network (GAN) to generate images of increasing aesthetic value. We validated that this network indeed was able to increase the aesthetic value of an image by letting participants decide which of two presented images they considered more beautiful. As our validation was successful, we were justified to use the generated images to extract low- and mid-level features contributing to their aesthetic value. We compared the brightness, contrast, sharpness, saturation, symmetry, colorfulness, and visual complexity levels of "low-aesthetic" images to those of "high-aesthetic" images. We found that all of these features increased for the beautiful images, implying that they may play an important role underlying the aesthetic value of an image. With this study, we have provided further evidence for the potential value GANs may have for research concerning beauty.

Anger is red, sadness is blue: Emotion depictions in abstract visual art by artists and non-artists.

Through the manipulation of color and form, visual abstract art is often used to convey feelings and emotions. Here, we explored how colors and lines are used to express basic emotions and whether non-artists express emotions through art in similar ways as trained artists. Both artists and non-artists created abstract color drawings and line drawings depicting six emotions (i.e., anger, disgust, fear, joy, sadness, and wonder). To test whether people represented basic emotions in similar ways, we computationally predicted the emotion of a given drawing by comparing it to a set of references created by averaging across all other participants' drawings within each emotion category. We found that prediction accuracy was higher for color drawings than line drawings and higher for color drawings by non-artists than by artists. In a behavioral experiment, we found that people (N = 242) could also accurately infer emotions, showing the same pattern of results as our computational predictions. Further computational analyses of the drawings revealed systematic use of certain colors and line features to depict each basic emotion (e.g., anger is generally redder and more densely drawn than other emotions, sadness is more blue and contains more vertical lines). Taken together, these results imply that abstract color and line drawings are able to convey certain emotions based on their visual features, which are also used by human observers to understand the intended emotional connotation of abstract artworks.

The Order & Complexity Toolbox for Aesthetics (OCTA): A systematic approach to study the relations between order, complexity, and aesthetic appreciation.

Do individuals prefer stimuli that are ordered or disordered, simple or complex, or that strike the right balance of order and complexity? Earlier research mainly focused on the separate influence of order and complexity on aesthetic appreciation. When order and complexity were studied in combination, stimulus manipulations were often not parametrically controlled, only rather specific types of order (i.e., balance or symmetry) were usually studied, and/or the multidimensionality of order and complexity was largely ignored. Progress has also been limited by the lack of an easy way to create reproducible and expandible stimulus sets, including both order and complexity manipulations. The Order & Complexity Toolbox for Aesthetics (OCTA), a Python toolbox that is also available as a point-and-click Shiny application, aims to fill this gap. OCTA provides researchers with a free and easy way to create multi-element displays varying qualitatively (i.e., different types) and quantitatively (i.e., different levels) in order and complexity, based on regularity and variety along multiple element features (e.g., shape, size, color, orientation). The standard vector-based output is ideal for experiments on the web and the creation of dynamic interfaces and stimuli. OCTA will not only facilitate reproducible stimulus construction and experimental design in research on order, complexity, and aesthetics. In addition, OCTA can be a very useful tool in any type of research using visual stimuli, or even to create digital art. To illustrate OCTA's potential, we propose several possible applications and diverse questions that can be addressed using OCTA.

Effects of Temporal Expectations on the Perception of Motion Gestalts.

Gestalt psychology has traditionally ignored the role of attention in perception, leading to the view that autonomous processes create perceptual configurations that are then attended. More recent research, however, has shown that spatial attention influences a form of Gestalt perception: the coherence of random-dot kinematograms (RDKs). Using ERPs, we investigated whether temporal expectations exert analogous attentional effects on the perception of coherence level in RDKs. Participants were presented fixed-length sequences of RDKs and reported the coherence level of a target RDK. The target was indicated immediately after its appearance by a postcue. Target expectancy increased as the sequence progressed until target presentation; afterward, remaining RDKs were perceived without target expectancy. Expectancy influenced the amplitudes of ERP components P1 and N2. Crucially, expectancy interacted with coherence level at N2, but not at P1. Specifically, P1 amplitudes decreased linearly as a function of RDK coherence irrespective of expectancy, whereas N2 exhibited a quadratic dependence on coherence: larger amplitudes for RDKs with intermediate coherence levels, and only when they were expected. These results suggest that expectancy at early processing stages is an unspecific, general readiness for perception. At later stages, expectancy becomes stimulus specific and nonlinearly related to Gestalt coherence.

Flexibility of emerging face categorization at different levels of abstraction.

Categorization of visual stimuli at different levels of abstraction relies on the encoding of relevant diagnostic features present at different spatial scales. We used the Eidolon Factory, an image-manipulation algorithm that introduces random disarray fields across spatial scales, to study how such a process flexibly combines perceptual information to perform successful categorization depending on task demands. Images of animal faces, human faces, and everyday objects were disarrayed coherently (random fields correlated) or incoherently (random fields randomized) to create a family of 50 eidolons per stimulus image with increasing disarray. Participants (N = 243) viewed each family of eidolons in a smooth sequence from maximum disarray to no disarray and performed a category verification task either at the superordinate (any face type) or basic (human face only) levels at two levels of uncertainty: participants in one group used their gut feeling to respond, whereas another group had to be sure of their decision. When participants used their gut feeling to respond, we observed a superordinate-level advantage. When they were sure of their response, we observed a basic-level advantage. Coherently disarrayed sequences impaired target detection compared to incoherently disarrayed sequences for both levels of response certainty. Furthermore, participants' sensitivity in the Any Face condition increased when they observed coherently disarrayed sequences and had to be sure of their response. These results suggest that the visual system does not strictly adhere to feedforward processing but flexibly adjusts to the relevant perceptual information depending on task context.

Perception of the ambiguous motion quartet: A stimulus-observer interaction approach.

Visual perception is the result of a highly complex process depending on both stimulus and observer characteristics and, importantly, their interactions. Generating robust theories and making precise predictions in light of this complexity can be challenging, and the interaction of stimulus- and observer-related effects is often neglected or understated. In the current study, we examined inter- and intra-individual differences and the effects of a wide range of three stimulus characteristics (i.e., spatial distance, temporal distance, and spatial location). Our results indicate that not all individuals show the same group average stimulus-driven effects on the perception of a motion quartet and that these effects are not always equal across the entire stimulus range. Moreover, we observed that there are clear individual differences in spontaneous perceptual dynamics and that these can be overridden by some but not all stimulus manipulations. We conclude that considering different stimulus manipulations, different observers, and their interactions can provide a more nuanced and informative view on the processes governing visual perception. This study examines the effect of spatial distance, spatiotemporal distance, spatial location, and individual differences on the perception of the ambiguous motion quartet.

Video assistant referees (VAR): The impact of technology on decision making in association football referees.

The use of technology has been proposed to improve decision-making in sport officials. The implementation of the video Assistant Referee (VAR) in association football is one example of how technology can be used to assist decision making, although its impact remains unknown. In 2195 competitive football matches across 13 countries, the VAR conducted 9732 checks for potential match-changing incidents, with the median duration of a check being 22 seconds. The checks resulted in a total of 795 reviews, with a median duration of 62.0 s for on-field reviews (N = 534) and 15.0 s for VAR-only reviews (N = 261).We report that the predictive odds for making the correct decision after VAR intervention were significantly higher than for the initial referee's decision, with accuracy increasing from 92.1% to 98.3%. Findings have implications for the current debate about the introduction of technology in association football and may help set guidelines regarding the use of technology across other sports and professional domains.

Pinpointing the optimal spatial frequency range for automatic neural facial fear processing.

Faces convey an assortment of emotional information via low and high spatial frequencies (LSFs and HSFs). However, there is no consensus on the role of particular spatial frequency (SF) information during facial fear processing. Comparison across studies is hampered by the high variability in cut-off values for demarcating the SF spectrum and by differences in task demands. We investigated which SF information is minimally required to rapidly detect briefly presented fearful faces in an implicit and automatic manner, by sweeping through an entire SF range without constraints of predefined cut-offs for LSFs and HSFs. We combined fast periodic visual stimulation with electroencephalography. We presented neutral faces at 6 â€‹Hz, periodically interleaved every 5th image with a fearful face, allowing us to quantify an objective neural index of fear discrimination at exactly 1.2 â€‹Hz. We started from a stimulus containing either only very low or very high SFs and gradually increased the SF content by adding higher or lower SF information, respectively, to reach the full SF spectrum over the course of 70 â€‹s. We found that faces require at least SF information higher than 5.93 cycles per image (cpi) to implicitly differentiate fearful from neutral faces. However, exclusive HSF faces, even in a restricted SF range between 94.82 and 189.63 cpi already carry the critical information to extract the emotional expression of the faces.

Assessment tool for visual perception deficits in cerebral visual impairment: development and normative data of typically developing children.

AIM: To develop an assessment tool that measures a wide range of visual perceptual deficits common in cerebral visual impairment (CVI) and to provide normative data from typically developing children between 3 and 6 years of age. METHOD: Test development reflected cross-talk between vision research and clinical relevance for CVI. The Children's Visual Impairment Test for 3- to 6-year-olds (CVIT 3-6) includes 14 subtests covering four domains of visual perception: Object Recognition, Degraded Object Recognition, Motion Perception, and Global-Local Processing. Normative data were collected from 301 typically developing children (mean age 4y 8mo [SD 9.7mo]; 148 females, 153 males). A questionnaire was administered to parents about pregnancy duration, birth, and developmental problems. RESULTS: Average total CVIT 3-6 performance was 60.1 (SD 5.5) out of 70. The cut-off score for normal visual perception (53) was set at the 10th centile of scores in typically developing children. Multiple regression indicated CVIT 3-6 visual perception scores increase with age for children born at 36 weeks' gestational age or later (ß=-18.03, 95% confidence interval -31.31 to -4.75). INTERPRETATION: CVIT 3-6 is a tool to assess a wide range of visual perceptual deficits common in CVI. Age-dependent normative data are available because we found performance increased with age. WHAT THE PAPER ADDS: A test for visual perceptual deficits common in cerebral visual impairment. Visual perceptual functions improve with age in full-term typically developing children.

HERRAMIENTA DE EVALUACIÓN PARA LAS DEFICIENCIAS DE LA PERCEPCIÓN VISUAL EN LA DISCAPACIDAD VISUAL CEREBRAL: DESARROLLO Y DATOS NORMATIVOS DE NIÑOS CON DESARROLLO TÍPICO: OBJETIVO: Desarrollar una herramienta de evaluación que mida una amplia gama de déficits de percepción visual comunes en la discapacidad visual cerebral (CVI) y proporcionar datos normativos de niños con un desarrollo típico entre los 3 y los 6 años de edad. MÉTODO: El desarrollo de la prueba reflejó la alineación de contenidos entre la investigación de la visión y la relevancia clínica para la CVI. La prueba de discapacidad visual para niños de 3 a 6 años (CVIT 3-6) incluye 14 subpruebas que cubren cuatro dominios de la percepción visual: reconocimiento de objetos, reconocimiento de objetos con fondos borrosos, percepción de movimiento y procesamiento global y local. Se recopilaron datos normativos de 301 niños con desarrollo típico (edad promedio 4 años y 8 meses [DS 9,7 meses]; 148 mujeres, 153 varones). Se administró un cuestionario a los padres sobre la duración del embarazo, el parto y los problemas de desarrollo. RESULTADOS: El rendimiento promedio total de CVIT 3-6 fue de 60,1 (DS 5,5) sobre 70. El puntaje límite para la percepción visual normal (53) se estableció en el décimo centil de puntajes en niños con un desarrollo típico. La regresión múltiple indicó que las puntuaciones de percepción visual CVIT 3-6 aumentan con la edad para los niños nacidos a las 36 semanas de edad gestacional o más tarde (ß = -18,03, intervalo de confianza del 95% -31,31 a -4,75). INTERPRETACIÓN: CVIT 3-6 es una herramienta para evaluar una amplia gama de déficits de percepción visual comunes en la CVI. Los datos normativos que dependen de la edad están disponibles porque encontramos que el rendimiento aumentó con la edad.

INSTRUMENTO DE AVALIAÇÃO PARA DÉFICITS DE PERCEPÇÃO VISUAL NA DEFICIÊNCIA VISUAL CEREBRAL: DESENVOLVIMENTO E DADOS NORMATIVOS DE CRIANÇAS COM DESENVOLVIMENTO TÍPICO: OBJETIVO: Desenvolver um instrumento de avaliação que mensure uma variedade de déficits de percepção visual comuns na deficiência visual cerebral (DVC) e fornecer dados normativos de crianças com desenvolvimento típcico entre 3 e 6 anos de idade. MÉTODO: O desenvolvimento do teste refletiu a comunicação entre pesquisas relacionadas à visão e a relevância clínica para a DVC. O Teste da Deficiência Visual para Crianças direcionado para a população de 3 a 6 anos de idade (TDVC-3-6) inclui 14 subtestes que cobrem quatro domínios da percepção visual: reconhecimento de objetos, reconhecimento de objetos diminuída, percepção de movimento, e processamento global-local. Dados normativos foram coletados em 301 crianças com desenvolvimento típico (média de idade 4a 8m [DP 9,7 m]; 148 do sexo feminino, 153 do sexo masculino). Um questionário foi administrado aos pais sobre a duração da gestação, nascimento e problemas relacionados ao desenvolvimento. RESULTADOS: O desempenho médio total no TDVC 3-6 foi 60,1 (DP 5,5) em um total de 70. O escore de corte para percepção visual normal (53) foi estabelecido como o 10o. percentil de escores em crianças com desenvolvimento típico. Regressão múltipla indicou que escores de percepção do TDVC 3-6 aumentam com a idade para crianças nascidas com 36 semanas de idade gestacional ou mais (ß=-18,03, 95% intervalo de confiança -31,31 a -4,75). INTERPRETAÇÃO: O TDVC 3-6 é um instrumento para avaliar uma variedade de déficits da percepção visual comuns em DVC. Dados normativos relacionados à idade estão disponíveis, pois observamos que o desempenho aumentou com a idade.

Assessment tool for visual perception deficits in cerebral visual impairment: reliability and validity.

AIM: To evaluate the reliability and validity of the Children's Visual Impairment Test for 3- to 6-year-olds (CVIT 3-6). METHOD: Reliability was assessed via test-retest correlation and intraclass correlation coefficient (ICC) in typically developing children, children with cerebral visual impairment (CVI), intellectual impairment, and simulated impaired vision (validation groups n=59, mean developmental age=4y 10mo, 27 females, 32 males). Internal validity was evaluated with a confirmatory factor analysis on the normative sample (n=301, median age=4y 8mo, SD=9.7mo, 148 females, 153 males). External validity was assessed by correlating performance on CVIT 3-6 with L94, the Beery-Buktenica Developmental Test of Visuo-Motor Integration (Beery-VMI), the Freiburg Vision Test, the revised Snijders-Oomen Nonverbal Intelligence Test for children between 2 years 6 months and 7-years-old (SON-R 2.5-7), and the Social Responsiveness Scale (SRS) questionnaire and by comparing performance between validation groups. RESULTS: We observed very good test-retest reliability (r=0.82, p<0.001, ICC=0.80) and confirmed the hypothesized factor structure (comparative fit index=1; Tucker-Lewis index=1.045). We found high correlations with tests with a strong visual perception component (L94: r=0.74, p<0.001; SON-R 2.5-7: r=0.37, p=0.01) and low correlations with other tests (Beery-VMI: r=0.25, p=0.09; SRS: r=0-0.26, p=0.09). Lowest scores were observed for children with CVI compared to the other validation groups (F[3,44]=5.1, p=0.003). INTERPRETATION: CVIT 3-6 is grounded in knowledge of visual perception. The tool specifically measures CVI-related visual perception deficits and is not mediated by intellectual abilities or low visual acuity. WHAT THE PAPER ADDS: Evidence for good test-retest reliability of the Children's Visual Impairment Test for 3- to 6-year-olds (CVIT 3-6). Factor structure of normative data reflects CVIT 3-6's foundations in vision science. CVIT 3-6 specifically measures visual perception impairments. CVIT 3-6 performance is not influenced by intelligence or low visual acuity.

Visuoperceptual profiles of children using the Flemish cerebral visual impairment questionnaire.

AIM: To investigate the underlying factor structure of the 46-item Flemish cerebral visual impairment (CVI) questionnaire, differentiate the factor scores of children with and without CVI, and examine the impact of comorbidities on factor scores. METHOD: The records of 630 children (386 males, 244 females; median age 77mo; interquartile range 63-98mo) who visited the CVI clinic and the Centre for Developmental Disabilities at the University Hospitals of Leuven from 2001 to 2018 were reviewed systematically. Inclusion criteria included an up-to-date questionnaire, a definitive diagnosis, and clinical assessment. RESULTS: Three hundred and forty-five children (179 with CVI [108 males, 71 females; median age 74mo; interquartile range 61-93mo] and 166 without CVI [110 males, 56 females; median age 88mo; interquartile range 70-107mo]) were included. An exploratory factor analysis resulted in a 5-factor (object and face processing impairments; visual (dis)interest; clutter and distance viewing impairments; moving in space impairments; and anxiety-related behaviours) biologically and clinically plausible model, which retained 35 items and explained 56% of the total variance. Mann-Whitney U tests indicated that factors 1 to 4 were significantly higher in children with CVI compared to children without CVI (p-values ranged from p<0.001 to p<0.05; effect sizes ranged from 0.11 to 0.33); factor 5 showed no differences. Autism, developmental coordination disorder, epilepsy, and cerebral palsy impacted factor scores. INTERPRETATION: A 5-factor structure of the Flemish CVI questionnaire differentiates children with and without CVI. Comorbidities should be accounted for when researching CVI. WHAT THIS PAPER ADDS: Cerebral visual impairment (CVI) is characterized by impaired object and face processing and impaired visual interest. CVI is also characterized by impaired clutter and distance viewing, and impaired moving in space. All children (with or without CVI) demonstrated anxiety-related behaviours. Autism affected object/face processing, whereas developmental coordination disorder, epilepsy, and cerebral palsy affected visual interest.

Perfis visuoperceptuais de crianças usando o questionário Flemish de deficiência visual cerebral OBJETIVOS: Investigar a estrutura de fator do questionário Flemish de deficiência visual cerebral (DVC) com 46 itens, diferenciar os escores de fator de crianças com e sem DVC, e examinar o impacto de comorbidades nos escores de fator. MÉTODO: Os prontuários de 630 crianças (386 do sexo masculino, 244 do sexo feminino; idade mediana 77m; intervalo interquartil 63-98m;) que visitaram a clínica de DVC e o Centro para Desordens do Desenvolvimento nos Hospitais Universitários de Leuven de 2001 a 2018 foram sistematicamente revisados. Os critérios de inclusão foram um questionário atualizado, um diagnóstico definitivo, e uma avaliação clínica. RESULTADOS: Trezentas e quarenta e cinco crianças (179 com DVC [108 do sexo masculino, 71 do sexo feminino; idade mediana 74m; intervalo interquartil 61-93m] e 166 sem DVC [110 do sexo masculino, 56 do sexo feminino; idade mediana 88m; intervalo interquartil 70-107m]) foram incluídas. Uma análise exploratória de fator resultou em um modelo com 5 fatores (deficiências no processamento de objeto e face; (des)interesse visual; deficiências na visão de espaços abarrotados e distância; deficiências na movimentação no espaço; e comportamentos relacionados a ansiedade) biológica e clinicamente plausível, que reteve 35 itens e explicou 56% da variância total. Os testes U de Mann-Whitney indicaram que fatores de 1 a 4 foram significativamente mais altos nas crianças com DVC comparadas com aquelas sem (valores de p variaram de p<0,001 a p<0,05; os tamanhos de efeito variaram de 0,11 a 0,33); o fator 5 não mostrou diferenças. Autismo, transtorno do desenvolvimento da coordenação, epilepsia e paralisia cerebral impactaram os escores de fator. INTERPRETAÇÃO: Uma estrutura com 5 fatores do questionário Flemish para DVC diferencia crianças com e sem DVC. Comorbidades devem ser consideradas quando se pesquisar a DVC.

Perfis visuoperceptuais de crianças usando o questionário Flemish de deficiência visual cerebral OBJETIVOS: Investigar a estrutura de fator do questionário Flemish de deficiência visual cerebral (DVC) com 46 itens, diferenciar os escores de fator de crianças com e sem DVC, e examinar o impacto de comorbidades nos escores de fator. MÉTODO: Os prontuários de 630 crianças (386 do sexo masculino, 244 do sexo feminino; idade mediana 77m; intervalo interquartil 63-98m;) que visitaram a clínica de DVC e o Centro para Desordens do Desenvolvimento nos Hospitais Universitários de Leuven de 2001 a 2018 foram sistematicamente revisados. Os critérios de inclusão foram um questionário atualizado, um diagnóstico definitivo, e uma avaliação clínica. RESULTADOS: Trezentas e quarenta e cinco crianças (179 com DVC [108 do sexo masculino, 71 do sexo feminino; idade mediana 74m; intervalo interquartil 61-93m] e 166 sem DVC [110 do sexo masculino, 56 do sexo feminino; idade mediana 88m; intervalo interquartil 70-107m]) foram incluídas. Uma análise exploratória de fator resultou em um modelo com 5 fatores (deficiências no processamento de objeto e face; (des)interesse visual; deficiências na visão de espaços abarrotados e distância; deficiências na movimentação no espaço; e comportamentos relacionados a ansiedade) biológica e clinicamente plausível, que reteve 35 itens e explicou 56% da variância total. Os testes U de Mann-Whitney indicaram que fatores de 1 a 4 foram significativamente mais altos nas crianças com DVC comparadas com aquelas sem (valores de p variaram de p<0,001 a p<0,05; os tamanhos de efeito variaram de 0,11 a 0,33); o fator 5 não mostrou diferenças. Autismo, transtorno do desenvolvimento da coordenação, epilepsia e paralisia cerebral impactaram os escores de fator. INTERPRETAÇÃO: Uma estrutura com 5 fatores do questionário Flemish para DVC diferencia crianças com e sem DVC. Comorbidades devem ser consideradas quando se pesquisar a DVC.

The representation of symmetry in multi-voxel response patterns and functional connectivity throughout the ventral visual stream.

Several computational models explain how symmetry might be detected and represented in the human brain. However, while there is an abundance of psychophysical studies on symmetry detection and several neural studies showing where and when symmetry is detected in the brain, important questions remain about how this detection happens and how symmetric patterns are represented. We studied the representation of (vertical) symmetry in regions of the ventral visual stream, using multi-voxel pattern analyses (MVPA) and functional connectivity analyses. Our results suggest that neural representations gradually change throughout the ventral visual stream, from very similar part-based representations for symmetrical and asymmetrical stimuli in V1 and V2, over increasingly different representations for symmetrical and asymmetrical stimuli which are nevertheless still part-based in both V3 and V4, to a more holistic representation for symmetrical compared to asymmetrical stimuli in high-level LOC. This change in representations is accompanied by increased communication between left and right retinotopic areas, evidenced by higher interhemispheric functional connectivity during symmetry perception in areas V2 and V4.

Task-set control, chunking, and hierarchical timing in rhythm production.

We investigated task-set control processes and chunking in 16 novices and 16 amateur musicians, who produced unimanual rhythms in three experimental conditions: low-level timing tasks required isochronous tapping at constant target durations; sequencing tasks consisted of individual rhythmic patterns comprising multiple target durations; the task-set control condition required alternations between two rhythmic patterns. According to our hierarchical timing control model conditions differed in their task-set control demands necessary to provide rhythm programs for the sequencing of individual intervals. Transitions at predicted chunk boundaries were marked by increased frequencies of sequence errors, relative lengthening of intervals preceding the switch to a new rhythm chunk, and increased variabilities in intervals immediately following a switch. Amateur musicians showed superior timing (less variability) in complex rhythm tasks. Moreover, they made fewer sequence errors than novices at set-switch points with their error patterns suggesting that they relied on larger chunks compared with novices. Our findings elucidate the time course of task reconfiguration processes in rhythm production and the role of chunking in the context of musical skill.

Incidental image memorability.

Recent studies using intentional memory tasks showed that images differ consistently in memorability. Here, we used a surprise recognition memory test. We asked how incidental encoding would affect the consistency and ranking of the memorability scores. If memorability is truly an intrinsic property of the image, one should not expect large differences between incidental and intentional conditions. On the other hand, participants might process images differently when not anticipating a memory test, yielding different results. The study list of our incidental memory task was identical to our previous, intentional study. Participants were to watch the images of this list carefully as they appeared on the screen one by one (free viewing); supposedly for a study about eye movements. Afterwards, a surprise recognition memory test was administered. Despite the free viewing instructions during the study phase, the resulting incidental image memorability scores still showed high levels of consistency across participants. In addition, the overlap between the incidental and intentional memorability ranking was large. These results provide further support for the idea of memorability as an intrinsic image property and add to its ecological validity, as people rarely memorise images intentionally.

Does task relevance shape the 'shift to global' in ambiguous motion perception?

Perception can differ even when the stimulus information is the same. Previous studies have demonstrated the importance of experience and relevance on visual perception. We examined the influence of perceptual relevance in an auxiliary task on subsequent perception of an ambiguous stimulus. Observers were presented with an ambiguous motion stimulus that could either be perceived as rotating dot pairs ("local") or pulsating geometrical figures ("global"). Prolonged perception of this stimulus is characterized by a "shift to global", but it remained unclear whether this process is due to relevance of the global percept or mere exposure to the stimulus. During a relevance learning phase over 5 successive days, participants were divided into conditions determining the relevant percept in an auxiliary task: local, global, or none (active exposure). In a pre- and posttest, individual points of subjective equality between local and global percepts were measured. Results indicate that there is indeed a shift to global. Interestingly, auxiliary task relevance does not seem to modify this process.