Beauty and the sharp fangs of the beast: degree of angularity predicts perceived preference and threat.

The evaluation of angular vs. curved forms has a long history in psychology but few of the many studies conducted have examined actual degree of angularity. In two experiments, we present observers with randomly positioned and randomly oriented texture displays of angles viewed within a circular frame. The angle conditions varied from 0° to 180° in 20° increments, covering the entire spectrum of possibilities including acute, obtuse, right, and straight line angles. In Experiment 1, 25 undergraduates rated the perceived beauty of these displays. In Experiment 2, the same stimulus set and procedure were used with 27 participants instead judging perceived threat. Based on the findings in the literature, we predicted that sharper angles would be judged less beautiful and more threatening. The results were mostly confirmed. Acute angles are preferred less but there are also distinct preferences for right angles and straight lines, perhaps due to their greater familiarity in constructed environments. There was a consistent and anticipated finding for threat in the second study: the sharper an angle, the greater its perceived threat. Fear of sharp objects as assessed in a personality questionnaire was found to positively correlate with threat judgements. Future work should look more closely at degree of angularity in embedded object contours and at individual response differences.

'When I can ride my bike, I think, am I at all as sick as they say?' An exploration of how men with advanced lung cancer form illness perceptions in everyday life.

OBJECTIVE: The purpose of this study was to explore how men with advanced lung cancer form perceptions of their illness in everyday life and how this influences perceptions about rehabilitation. METHODS: Constructivist grounded theory principles guided the collection and analysis of data from in-depth interviews with 10 men with advanced lung cancer. RESULTS: The findings show that the men's illness perception was fluid, contextual and formed by interrelated factors. Engaging in daily activities and maintaining everyday life was a strong influence on their illness perception. CONCLUSION: In order to make rehabilitation relevant to men with lung cancer, consideration should be given to how the men's everyday lives may be incorporated into the service provision.

An exploration of the nomological network of trypophobia.

BACKGROUND: Trypophobia is characterised by an aversion to or even revulsion for patterns of holes or visual stimuli featuring such patterns. Past research has shown that trypophobic stimuli trigger emotional and physiological reactions, but relatively little is known about the antecedents, prodromes, or simply covariates of trypophobia. AIM: The goals of this study were (a) to draw the contours of the nomological network of trypophobia by assessing the associations of symptoms of trypophobia with several constructs that were deemed relevant from past research on anxiety disorders and specific phobias, (b) to compare such associations with those found for symptoms of spider phobia and blood and injection phobia (alternative dependent variables), and (c) to investigate the main effect of gender on symptoms of trypophobia and replicate the association of gender with symptoms of spider phobia and blood and injection phobia (higher scores for women). METHODS: Participants (N = 1,134, 53% men) in this cross-sectional study completed an online questionnaire assessing the constructs of interest. RESULTS: Most assessed constructs typically associated with anxiety disorders (neuroticism, conscientiousness, anxiety sensitivity, trait anxiety, disgust sensitivity, and disgust propensity) were also associated with trypophobia in the predicted direction. All of these constructs were also associated with spider phobia and blood and injection phobia. Behavioral inhibition was negatively associated with trypophobia and spider phobia-contrary to what was expected, but positively with blood and injection phobia. We found no gender difference in trypophobia, whereas women scored higher on spider phobia and blood and injection phobia. DISCUSSION: Although some differences were observed, the nomological network of trypophobia was largely similar to that of spider phobia and blood and injection phobia. Further studies are needed to clarify similarities and dissimilarities between trypophobia and specific phobia.

Learning to perceive shape from temporal integration following late emergence from blindness.

Visual perception requires massive use of inference because the 3D structure of the world is not directly provided by the sensory input.1 Particularly challenging is anorthoscopic vision-when an object moves behind a narrow slit such that only a tiny fraction of it is visible at any instant. Impressively, human observers correctly recognize objects in slit-viewing conditions by early childhood,2,3 via temporal integration of the contours available in each sliver.4,5 But can this capability be acquired if one has been effectively blind throughout childhood? We studied 23 Ethiopian children which had bilateral early-onset cataracts-resulting in extremely poor vision in infancy-and surgically treated only years later. We tested their anorthoscopic vision, precisely because it requires a cascade of demanding visual inference processes to perceive veridical shape. Failure to perform the task may allow mapping specific bottlenecks for late visual recovery. The patients' visual acuity typically improved substantially within 6 months post-surgery. Still, at this stage many were unable to recover shape under slit-viewing conditions, although they could infer the direction of global motion. However, when retested later, almost all patients could judge shape in slit-conditions necessitating temporal integration. This acquired capability often transferred to novel stimuli, in similar slit-viewing conditions. Thus, learning was not limited to the specific visual features of the original shapes. These results indicate that plasticity of sophisticated visual inference routines is preserved well into adolescence, and vision restoration after prolonged early-onset blindness is feasible to a greater extent than previously thought.

Entremeios dos sentidos: discursividade sobre os determinantes da tuberculose multidroga-resistente e as barreiras para o cuidado em saúde / Intermediations of the senses: discourse on the determinants of multidrug-resistant tuberculosis and the barriers to health care

multidroga resistência é um fenômeno evolutivo considerado iatrogênico, devido a sua origem ser proveniente de tratamentos inadequados, abandono e/ou por esquemas terapêuticos de baixa potência contra o Mycobacterium tuberculosis. Dessa forma, tem-se como objetivo analisar a discursividade das pessoas com tuberculose multidroga-resistente acerca dos determinantes da sua condição de saúde, e as barreiras enfrentadas para o cuidado em saúde em Ribeirão Preto, São Paulo, Brasil. Trata-se de um estudo qualitativo exploratório, que utilizou o referencial teórico-metodológico da Análise de Discurso de Matriz Francesa, elaborado a partir do Consolidated Criteria for Reporting Qualitative Research, realizado em Ribeirão Preto, São Paulo, Brasil. Quatorze participantes foram elegíveis aos critérios de inclusão, entretanto, sete participantes, que estavam em tratamento no momento da entrevista, participaram do estudo. Da análise dos discursos dos participantes emergiram quatro blocos discursivos: (1) Impacto dos determinantes sociais no desenvolvimento da tuberculose multidroga-resistente; (2) Barreiras enfrentadas para o cuidado em saúde da tuberculose multidroga-resistente; (3) Percepções sobre os efeitos colaterais e seu impacto no tratamento da tuberculose multidroga-resistente; e (4) Tuberculose multidroga-resistente e COVID-19: um diálogo necessário. Por meio das formações discursivas, essas demonstraram os determinantes da tuberculose multidroga-resistente. Considerando a complexidade envolvida na dinâmica da tuberculose multidroga-resistente, avançar em termos de equidade em saúde, ou seja, na redução de desigualdades sociais, é um desafio para as políticas públicas, principalmente no atual contexto vivenciado no Brasil, de acentuada crise econômica, política e social. Os estressores psicossociais e a falta de suporte social também devem ser destacados como determinantes intermediários da saúde. O estudo também evidenciou a situação da COVID-19, que consiste como uma importante barreira para as pessoas acometidas pela doença que buscam atendimento. Os participantes relataram medo, insegurança e preocupação em relação ao retorno às consultas médicas, o que pode contribuir para o agravamento da tuberculose no cenário em estudo

Spatial specificity of alpha oscillations in the human visual system.

Alpha oscillations are strongly modulated by spatial attention. To what extent, the generators of cortical alpha oscillations are spatially distributed and have selectivity that can be related to retinotopic organization is a matter of continuous scientific debate. In the present report, neuromagnetic activity was quantified by means of spatial location tuning functions from 30 participants engaged in a visuospatial attention task. A cue presented briefly in one of 16 locations directing covert spatial attention resulted in a robust modulation of posterior alpha oscillations. The distribution of the alpha sources approximated the retinotopic organization of the human visual system known from hemodynamic studies. Better performance in terms of target identification was associated with a more spatially constrained alpha modulation. The present findings demonstrate that the generators of posterior alpha oscillations are retinotopically organized when modulated by spatial attention.

Domestic horses (Equus ferus caballus) fail to intuitively reason about object properties like solidity and weight.

From early infancy, humans reason about the external world in terms of identifiable, solid, cohesive objects persisting in space and time. This is one of the most fundamental human skills, which may be part of our innate conception of object properties. Although object permanence has been extensively studied across a variety of taxa, little is known about how non-human animals reason about other object properties. In this study, we therefore tested how domestic horses (Equus ferus caballus) intuitively reason about object properties like solidity and height, to locate hidden food. Horses were allowed to look for a food reward behind two opaque screens, only one of which had either the proper height or inclination to hide food rewards. Our results suggest that horses could not intuitively reason about physical object properties, but rather learned to select the screen with the proper height or inclination from the second set of 5 trials.

N-acetyl cysteine reverses bio-behavioural changes induced by prenatal inflammation, adolescent methamphetamine exposure and combined challenges.

RATIONALE: Schizophrenia is associated with prenatal inflammation and/or postnatal stressors such as drug abuse, resulting in immune-redox dysfunction. Antioxidants may offer therapeutic benefits. OBJECTIVES: The objective of this study is to investigate N-acetyl cysteine (NAC) as a therapeutic antioxidant to reverse schizophrenia-like bio-behavioural changes in rats exposed to maternal immune activation (MIA), adolescent methamphetamine (MA) or a combination thereof. METHODS: Sprague-Dawley offspring prenatally exposed to saline/lipopolysaccharide (LPS) received saline or MA (0.2-6 mg kg-1 twice daily × 16 days) during adolescence and divided into LPS, MA and LPS + MA groups. Vehicle/NAC (150 mg kg-1 × 14 days) was administered following MA/saline exposure on postnatal day 51-64. Social interaction, novel object recognition and prepulse inhibition (PPI) of startle, as well as regional brain monoamines, lipid peroxidation, plasma reactive oxygen species (ROS) and pro- and anti-inflammatory cytokines (TNF-α; IL-10), were assessed. RESULTS: NAC reversed LPS, MA and LPS + MA-induced anxiety-like social withdrawal behaviours, as well as MA and LPS + MA-induced deficits in recognition memory. PPI deficits were evident in MA, LPS and LPS + MA models, with NAC reversing that following LPS + MA. NAC reversed LPS, MA and LPS + MA-induced frontal cortical dopamine (DA) and noradrenaline (NA) elevations, LPS and LPS + MA-induced frontal cortical 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT) and striatal NA deficits as well as LPS + MA-induced frontal cortical 5-HT turnover. Decreased IL-10 in the LPS, MA and LPS + MA animals, and increased TNF-α in the LPS and MA animals, was reversed with NAC. NAC also reversed elevated lipid peroxidation and ROS in the LPS and LPS + MA animals. CONCLUSIONS: Prenatal LPS, LPS + postnatal MA challenge during adolescence, and to a lesser extent MA alone, promotes schizophrenia-like bio-behavioural changes later in life that are reversed by NAC, emphasizing therapeutic potential for schizophrenia and MA-associated psychosis. The nature and timing of the dual-hit are critical.

Percepção Subjetiva de Alunos do Curso de Educação Física sobre a Imagem Corporal e Variáveis Antropométricas de Homens Adultos / Subjective Perception of Physical Education Students on Body Image and Anthropometric Variables of Adult Men

Objetivo: O presente estudo comparou a percepção de discentes do curso de Bacharelado em Educação Física da Universidade Federal de Ouro Preto sobre a imagem corporal (IC), massa corporal (MC) e percentual de gordura (%G) em fotografias de homens adultos. Material e Métodos: Participaram do estudo 31 discentes de ambos os sexos (22,7 ± 2,9 anos), iniciantes (G-AV1) e concluintes (G-AV2) do curso de Bacharelado em Educação Física da Universidade Federal de Ouro Preto e 10 voluntários (GMOD; 22,7 ± 3,2 anos), não discentes do curso de Educação Física, não praticantes de exercício físico regular, do sexo masculino, que atuaram como modelos para obtenção de fotografias de corpo inteiro. Resultados: Os resultados não mostraram diferença significativa (p> 0.05) entre a avaliação da IC feita pelo G-AV1 e G-AV2, a partir das fotografias do G-MOD. Não foram encontradas diferenças (p> 0.05) entre a avaliação subjetiva da MC feita pelo G-AV1, G-AV2 e a MC do G-MOD. A avaliação do %G do G-MOD, realizadas pelo GAV1 e G-AV2 foi diferente (p< 0.05) dos valores do G-MOD. Conclusão: Concluiu-se que alunos iniciantes e concluintes do curso de Bacharelado em Educação Física da Universidade Federal de Ouro Preto têm percepção semelhante para a IC e MC, mas diferente para o %G de homens adultos. (AU)

Objective: This study compared the perception of undergraduate students of the bachelor course in Physical Education at Federal University of Ouro Preto (UFOP) on body image (BI), body mass (BM) and body fat percentage (BF%) through photographs of adult men.Material and Methods: This study included thirty-one students of both sexes (22.7 ± 2.9 years old), freshmen(G-AV1) and seniors(G-AV2) in Physical Education at Federal University of Ouro Preto, and 10 volunteers (G-MOD, 22.7 ± 3.2 years old), non-students of Physical Education, non-practitioners of regular physical exercise, who acted as models for obtaining full-body photographs. Results: The results showed no difference (p> 0.05) between the assessmentof BI made by G-AV1 and G-AV2 participants through G-MOD photographs. No differences (p> 0.05) were found between the subjective evaluation of BM made by G-AV1, G-AV2 and the measured BM of G-MOD. Evaluation of BF% in G-MOD made by G-AV1 and G-AV2 was different (p< 0.05) of measured BF% of G-MOD. Conclusion: Beginning and seniorstudents in Physical Education at Federal University of Ouro Preto have similar perception onBI and BM, but not on BF%, of adult men. (AU)

The painter from Sinaloa: artistic analysis of a case of spatial agnosia and neglect of visual shapes.

Paintings produced spontaneously by patients with neurological lesions represent a fascinating opportunity to analyze some aspects of the underlying disease and involved brain mechanisms. Many cases of artists who have suffered spatial neglect following a neurological disease have been reported in the literature. However, only a few studies evaluating the different subtypes of graphic neglect and aspects related to the construction of perspective (three dimensionality) in works of art have been published. In the present article, we present the case of an artist who, after resection of a central neurocytoma that affected the right thalamo-parietal connections, suffered an impairment of the ability to create perspective in his paintings and involuntary omission of only shapes in the left side of his paintings, although colors and contours were preserved.

Effects of nicotine on response inhibition and interference control.

Nicotine is a cholinergic agonist with known pro-cognitive effects in the domains of alerting and orienting attention. However, its effects on attentional top-down functions such as response inhibition and interference control are less well characterised. Here, we investigated the effects of 7 mg transdermal nicotine on performance on a battery of response inhibition and interference control tasks. A sample of N = 44 healthy adult non-smokers performed antisaccade, stop signal, Stroop, go/no-go, flanker, shape matching and Simon tasks, as well as the attentional network test (ANT) and a continuous performance task (CPT). Nicotine was administered in a within-subjects, double-blind, placebo-controlled design, with order of drug administration counterbalanced. Relative to placebo, nicotine led to significantly shorter reaction times on a prosaccade task and on CPT hits but did not significantly improve inhibitory or interference control performance on any task. Instead, nicotine had a negative influence in increasing the interference effect on the Simon task. Nicotine did not alter inter-individual associations between reaction times on congruent trials and error rates on incongruent trials on any task. Finally, there were effects involving order of drug administration, suggesting practice effects but also beneficial nicotine effects when the compound was administered first. Overall, our findings support previous studies showing positive effects of nicotine on basic attentional functions but do not provide direct evidence for an improvement of top-down cognitive control through acute administration of nicotine at this dose in healthy non-smokers.

The ideal male jaw angle--An Internet survey.

BACKGROUND: The ideal male jaw angle has not been established. With the advent of additive manufacturing, precise customized shaping is a reality. This study aimed to define the ideal masculine mandibular angle as an aid for 3-dimensional (3D) design. METHODS: An Internet survey was conducted using black/white photographs of celebrities and non-celebrities. Preferences regarding gonial angle (profile and frontal views), intergonial width and vertical jaw angle position (face frontal view), and angle curvature and definition in oblique views were obtained using simplified, unbalanced Likert scales. Constructs were defined for planning 3D implant designs. RESULTS: The preferred jaw angle had these characteristics: 130° in face profile view, intergonial width similar to facial width, vertical position in frontal view at the oral commissure or at least not below the lower lip, jawline slope in the face frontal view nearly parallel to (with a maximum 15° downward deviation from) a line extending from the lateral canthus to the alare, ascending ramus slope 65°-75° to the Frankfort horizontal, and curvature in the oblique view visible from earlobe to chin and not pointy. CONCLUSIONS: Photogrammetric analysis of panel preferences lead to constructs with values useful for the design of 3D printed jaw angles.

Distractor rejection in visual search breaks down with more than a single distractor feature.

Previous research has established that interference from irrelevant-but-salient color distractors occurs when observers search for variable-shape singletons among uniform shapes (singleton detection), but not when they look for a specific shape among mixed shapes (feature search). In the current study, we replicated this finding, and additionally, we introduced a random variation of color. Instead of always presenting the same target and distractor colors, colors were swapped randomly from trial to trial. With random color variation, interference from color distractors was generally stronger, and in particular, it also occurred in feature search mode, suggesting that observers were unable to focus on the relevant dimension (shape) even under the most favorable conditions. A second experiment showed that interference in feature search mode occurred with variable distractor color when target color was fixed, but not with variable target color when distractor color was fixed. Overall, the results question the view that interference in feature search is absent because observers monitor a single feature map (i.e., shape). Rather, random variation of an irrelevant feature induces participants to also monitor the irrelevant feature, which results in interference. Thus, complete distractor rejection is limited to situations with a single distractor feature.

The incidental binding of color and shape is insensitive to the perceptual load

Abstract The binding of information in visual short-term memory may occur incidentally when irrelevant information for the task at hand is stored together with relevant information. We investigated the process of the incidental conjunction of color and shape (Exp1) and its potential association with the selection of relevant information to the memory task (Exp2). The results in Exp1 show that color and shape are incidentally and asymmetrically conjugated: color interferes with the recognition of shape; however, shape does not interfere with the recognition of color. In Exp2, we investigated whether an increase in perceptual load would eliminate the processing of irrelevant information. The results of this experiment show that even with a high perceptual load, the incidental conjunction is not affected, and color remains to interfere with shape recognition, suggesting that the incidental conjunction is an automatic process. (AU)

Evaluating geodesic active contours in microcalcifications segmentation on mammograms.

Breast cancer is the most commonly occurring type of cancer among women, and it is the major cause of female cancer-related deaths worldwide. Its incidence is increasing in developed as well as developing countries. Efficient strategies to reduce the high death rates due to breast cancer include early detection and tumor removal in the initial stages of the disease. Clinical and mammographic examinations are considered the best methods for detecting the early signs of breast cancer; however, these techniques are highly dependent on breast characteristics, equipment quality, and physician experience. Computer-aided diagnosis (CADx) systems have been developed to improve the accuracy of mammographic diagnosis; usually such systems may involve three steps: (i) segmentation; (ii) parameter extraction and selection of the segmented lesions and (iii) lesions classification. Literature considers the first step as the most important of them, as it has a direct impact on the lesions characteristics that will be used in the further steps. In this study, the original contribution is a microcalcification segmentation method based on the geodesic active contours (GAC) technique associated with anisotropic texture filtering as well as the radiologists' knowledge. Radiologists actively participate on the final step of the method, selecting the final segmentation that allows elaborating an adequate diagnosis hypothesis with the segmented microcalcifications presented in a region of interest (ROI). The proposed method was assessed by employing 1000 ROIs extracted from images of the Digital Database for Screening Mammography (DDSM). For the selected ROIs, the rate of adequately segmented microcalcifications to establish a diagnosis hypothesis was at least 86.9%, according to the radiologists. The quantitative test, based on the area overlap measure (AOM), yielded a mean of 0.52±0.20 for the segmented images, when all 2136 segmented microcalcifications were considered. Moreover, a statistical difference was observed between the AOM values for large and small microcalcifications. The proposed method had better or similar performance as compared to literature for microcalcifications with maximum diameters larger than 460µm. For smaller microcalcifications the performance was limited.

Progressive cortical visual failure associated with occipital calcification and coeliac disease with relative preservation of the dorsal 'action' pathway.

We describe the first reported case of a patient with coeliac disease and cerebral occipital calcification who shows a progressive and seemingly selective failure to recognise visual stimuli. This decline was tracked over a study period of 22 years and occurred in the absence of primary sensory or widespread intellectual impairment. Subsequent tests revealed that although the patient was unable to use shape and contour information to visually identify objects, she was nevertheless able to use this information to reach, grasp and manipulate objects under central, immediate vision. This preservation of visuo-motor control was echoed in her day-to-day ability to navigate and live at home independently. We conclude that occipital calcification following coeliac disease can lead to prominent higher visual failure that, under prescribed viewing conditions, is consistent with separable mechanisms for visual perception and action control.

Vulnerabilidade de famílias de idosos assistidos pela Estratégia Saúde da Família / Vulnerabilidad de las familias de adultos mayores asistidas por la Estrategia Salud de la Familia / Vulnerability of families of elderly citizens cared for by the Family Health Strategy

RESUMO Objetivo: estudo descritivo, exploratório, de corte transversal, cujo objetivo foi identificar a vulnerabilidade de famílias de idosos assistidos pela Estratégia Saúde da Família (ESF). Método: foi desenvolvido por meio de entrevistas domiciliárias realizadas com uma amostra de 500 famílias de idosos assistidas por 32 equipes da ESF da cidade de Dourados, MS. O Índice de Desenvolvimento da Família (IDF) foi adaptado para classificá-las em função da situação de vulnerabilidade. Resultados: os resultados revelaram a presença de famílias multigeracionais, com baixa escolaridade entre os indivíduos com idade superior a 20 anos e alta taxa de analfabetismo entre os idosos. Identificaram-se 403 famílias em situação de vulnerabilidade aceitável, 95 em vulnerabilidade grave e duas famílias em situação de vulnerabilidade muito grave. As dimensões mais críticas do IDF foram os acessos ao conhecimento e ao trabalho. Conclusão: conclui-se que há necessidade de mais investimentos no cuidado a esses idosos e suas famílias na Atenção Básica. .

RESUMEN Objetivo: estudio descriptivo, exploratorio, transversal, con el objetivo de identificar la vulnerabilidad de familias adultos mayores asistidas por la Estrategia Salud de la Familia (ESF). Método: fue desarrollado mediante entrevistas a una muestra de 500 familias de adultos mayores bajo la responsabilidad de 32 equipos de ESF en la ciudad de Dourados, MS, Brasil. El Índice de Desarrollo de la Familia (IDF) fue adaptado para clasificar las familias de acuerdo a la situación de vulnerabilidad. Resultados: los resultados revelaron la presencia de familias multigeneracionales con bajo nivel de educación entre las personas mayores de 20 años y las altas tasas de analfabetismo entre los adultos mayores. Se identificaron 403 familias en situación de vulnerabilidad aceptable, 95 con vulnerabilidad grave y dos familias en situación de vulnerabilidad muy grave. Las dimensiones más críticas en el IDF fueron el acceso al conocimiento y al trabajo. Conclusión: se concluye que existe la necesidad de una mayor inversión, con un enfoque en la atención primaria, con el fin de atender a las personas mayores y sus familias. .

ABSTRACT Objective: the present descriptive, exploratory, cross-sectional study aimed to identify the vulnerability of families of elderly citizens cared for by the Family Health Strategy (FHS). Method: the research employed home interviews and was developed with a sample of 500 families of aged people cared for by 32 FHS teams in the city of Dourados, MS, Brazil. The Family Development Index (FDI) was adapted in order to classify the families according to their degree of vulnerability. Results: the results revealed the presence of multigenerational families with low educational levels among individuals over the age of 20 and high illiteracy rates among elderly citizens. There were 403 families whose vulnerability was acceptable, 95 in severe vulnerability, and two families in a condition of very severe vulnerability. The most critical dimensions of the FDI were the access to knowledge and to work. Conclusion: the study identifi ed that there is still a need for further investments that can assist these aged people and their families in the Primary Health Care. .

Effect of disparity on the perception of motion-defined contours

We present three experiments that explored the effect of binocular disparity on the perception of contours defined by motion in a Spatiotemporal Boundary Formation. Depending on the disparity, the stimulus is perceived as an object that moves behind a holed surface (occluded configuration) or as a luminous transparency that moves over a surface that contains dots (occluding configuration). In all of the experiments, we used a Vernier task to assess the strength of contour perception. In the first experiment, we measured acuity as a function of disparity for a range of speeds and dot densities. The results showed that, despite the difference in the percepts, acuity was similar in both situations, replicating the dependence on speed and dot density demonstrated in previous studies. In the second experiment, the results showed that the dynamics of contour integration were identical for both occluded and occluding configurations. In the third experiment, we tested whether the mechanism of contour integration works independently from the interpretation of the scene. In this experiment, we inverted the disparity during stimulus presentation so that the stimulus switched between occluded and occluding configurations. The results showed that the switch of the depth order increased the threshold to the value obtained with a shorter presentation time. This might be produced by a resetting of the integration process driven by the change of depth order. The results are discussed within a conceptual model that places the process of contour integration in the context of the perception of objects in a Spatiotemporal Boundary Formation...

Planificação e área total de paralelepípedo: análise das representações semióticas de alunos do ensino básico / Planning and total area of parallelepiped: analysis of semiotic representations by elementary and high school students

O trabalho analisou as representações semióticas produzidas por alunos do ensino fundamental e médio em duas situações: na tarefa de planificação do paralelepípedo e na primeira fase de solução de um problema envolvendo a área total do paralelepípedo. Fundamentou-se nas teorias de Raymond Duval sobre registros de representação semiótica e de Stephen Kosslyn acerca da formação e manipulação de imagens mentais. Foram sujeitos 842 estudantes com idades variando entre 14 e 18 anos, do nono ano do ensino fundamental e da terceira série do ensino médio de municípios pertencentes à região do Pontal do Triângulo Mineiro de Minas Gerais. Testes estatísticos mostraram que os sujeitos que produziram fracas representações para a planificação não produziram representações para o problema e, quando o fizeram, valeram-se de figuras planas; já os sujeitos que elaboraram boas planificações tenderam a utilizar, para o problema,mais figuras em perspectiva que planas. No geral, os sujeitos não transferiram as representações da planificação para a solução do problema

This study analyzed semiotic representations produced by students from middle and high school in two situations: the task of planning the parallelepiped and the first stage of solving a problem involving the total area of the parallelepiped. It was based on Raymond Duval's theory of semiotic representation registers and on Stephen Kosslyn's computational theory of mental images formation and manipulation. The subjects were 842 students aged between 14 and 18 from ninth grade of middle school and thirdgrade of high school in towns situated in the area of Pontal of Triângulo Mineiro, in Minas Gerais. Statistical tests showed that subjects who made low representations for the planning did not make any representation to the problem, and when they did it, they used flat figures, whereas subjects who developed good plans tended to use more figures in perspective than flat ones. Overall, the subjects did not transfer the planning representations to the solution of the problem