Exploring Binocular Visual Attention by Presenting Rapid Dichoptic and Dioptic Series.

This study addresses an issue in attentional distribution in a binocular visual system using RSVP tasks under Attentional Blink (AB) experimental protocols. In Experiment 1, we employed dichoptic RSVP to verify whether, under interocular competition, attention may be captured by a monocular channel. Experiment 2 was a control experiment, where a monoptic RSVP assessed by both or only one eye determines whether Experiment 1 monocular condition results were due to an allocation of attention to one eye. Experiment 3 was also a control experiment designed to determine whether Experiment 1 results were due to the effect of interocular competition or to a diminished visual contrast. Results from Experiment 1 revealed that dichoptic presentations caused a delay in the type stage of the Wyble's eSTST model, postponing the subsequent tokenization process. The delay in monocular conditions may be further explained by a visual attenuation, due to fusion of target and an empty frame. Experiment 2 evidenced the attentional allocation to monocular channels when forced by eye occlusion. Experiment 3 disclosed that monocular performance in Experiment 1 differs significantly from conditions with interocular competition. While both experiments revealed similar performance in monocular conditions, rivalry conditions exhibit lower detection rates, suggesting that competing stimuli was not responsible for Experiment 1 results. These findings highlight the differences between dichoptic and monoptic presentations of stimuli, particularly on the AB effect, which appears attenuated or absent in dichoptic settings. Furthermore, results suggest that monoptic presentation and binocular fusion stages were a necessary condition for the attentional allocation.

An integrative model of visual control of action / Um modelo integrativo do controle visual da ação / Un modelo integrador de lo control visual de la acción

The present study offers an integrative proposal of a model of visual control of action, specifically in relation to the visually directed tasks. Within these models, the calibration between visual signals and vestibulo-kinesthetic signals is of fundamental importance, especially in the case of visually directed tasks. The Hierarchical Control Model (Marken, 1985), the Functional Organization Model (Rieser et al., 1995), the Time-based Heuristics (Lederman et al., 1987), and the Model of Visual Control of Locomotion (Lee & Lishman, 1977b), are integrated into a single model, which still incorporates recent developments in empirical research. The proposed model provides a theoretical framework to guide the experimental research of the visual control of action, in order to determine the processing steps and paths not yet clarified by the empirical evidence.

O presente estudo apresenta uma proposta integrativa dos modelos de controle visual da ação, principalmente no que diz respeito às tarefas visualmente dirigidas. Dentro destes modelos, a calibração entre os sinais visuais e os sinais vestibulo-cinestésicos é de fundamental importância, especialmente no caso das tarefas visualmente dirigidas. O Modelo de Controle Hierarquizado (Marken, 1985), o Modelo de Organização Funcional (Rieser et al., 1995), a Heurística Temporal (Lederman et al., 1987) e o Modelo de Controle Visual da Locomoção (Lee & Lishman, 1977b), são integrados dentro de um único modelo, que ainda incorpora desenvolvimentos recentes da pesquisa empírica. O modelo proposto fornece um arcabouço teórico para orientar a pesquisa experimental do controle visual da ação, de forma a determinar as etapas e os fluxos processuais ainda não esclarecidos pelas evidências empíricas.

El presente estudio presenta una propuesta integradora de los modelos de control visual de la acción, principalmente con respecto a las tareas dirigidas visualmente. Dentro de estos modelos, la calibración entre señales visuales y señales vestibulo-kinestésicas es de fundamental importancia, especialmente en el caso de tareas dirigidas visualmente. El Modelo de Control Jerárquico (Marken, 1985), el Modelo de Organización Funcional (Rieser et al., 1995), la Heuristica Temporal (Lederman et al., 1987), y el Modelo de Control de Locomoción Visual (Lee & Lishman, 1977b) se integran en un solo modelo, que todavía incorpora desarrollos recientes en la investigación empírica. El modelo propuesto proporciona un marco teórico para guiar la investigación experimental del control visual de la acción, con el fin de determinar los pasos y flujos de procesamiento aún no aclarados por la evidencia empírica.

Independence of egocentric and exocentric direction processing in visual space

One major issue concerning investigations of visual perception is determination of the geometrical properties of visual space. To address this issue, one must determine the relationships between geometrical features of visual space, distance, direction, angle, and size. Consistent evidence indicates that visual angle is a determinant of perceived exocentric distance. Previous evidence suggests that exocentric distance and direction are hierarchically processed, with distance preceding direction. The present study investigated the relationship between the perceptual processing of egocentric direction and exocentric direction using a task that independently provides both perceptual variables in a single judgment. The results indicated that egocentric directions were systematically overestimated, and this was not caused by either the global shape of the layout or leg length effects. Exocentric directions presented a discontinuous pattern of overestimation of smaller angles that were subtended by radial orientations and accuracy of right angles that were subtended by horizontal orientations. This could be explained by the anisotropy of visual space, a well-established phenomenon from visual space studies. The analysis of the association between the processing of these two variables revealed independence between them in which exocentric direction processing did not depend on the processing of egocentric direction processing, and vice versa. The present results and prior evidence converge on the notion of hierarchical processing in which the visual system processes the egocentric distance of objects followed by exocentric distance processing and subsequent processing. The precise positions of egocentric and exocentric directions in this chain of processing remain to be determined.(AU)

Affective spatial compatibility task(AFFSCT): theory and applications / Tarefa de compatibilidade espacial afetiva (TCEA): teoria e aplicações / Tarea de compatibilidad espacial afectiva (TCEA): teoría y aplicaciones

Emotional stimuli are processed very efficiently, influencing physiological and behavioral responses as well as attention, perceptual processes and sensory-motor integration. In a previous work, we introduced a new paradigm, the Affective Spatial Compatibility task (AffSCt), to study whether the affective valence of the stimulus influences spatial compatibility effects. By using figures of soccer players of Favorite and Rival Teams as positive and negative valence stimuli, we found a normal Spatial Compatibility effect for the Favorite team and a reversed one for the Rival team. Here, we analyzed the time course of inhibitory and facilitatory effects of emotional valence by the Vincentization method. We found that for Favorite team, the facilitatory effect for the compatible condition, as compared to the incompatible one, increases as a function of the reaction time. In contrast, for Rival team, an opposite trend was found, in which inhibitory effect beEmotional stimuli are processed verycomes stronger for slower responses. We suggest that AffSCt is a powerful technology for investigating approach/avoidance effects and that it may be useful for diagnosing and following up the treatment of affective and behavioral disorders, such as anxiety, panic and ADHD. Potential applications in social psychology and consumer studies are also considered.(AU).

Os estímulos emocionais são processados de forma muito eficiente, influenciando as respostas fisiológicas e comportamentais, bem como a atenção, a percepção e a integração sensório-motora. Em um trabalho anterior, propusemos um novo paradigma, a Tarefa Afetiva de Compatibilidade Espacial (AffSCt), para estudar se a valência afetiva do estímulo influenciaria os efeitos de compatibilidade espacial. Ao usarmos figuras de jogadores de futebol dos times Favorito e Rival como estímulos de valência positiva e negativa, respectivamente, encontramos um efeito de compatibilidade espacial normal para o time Favorito e um invertido para o time Rival. No presente trabalho, foi analisado o desenvolvimento temporal dos efeitos inibitórios e facilitatórios da valência emocional pelo método da Vincentização. Descobrimos que, para o time Favorito, o efeito facilitatório na condição compatível em relação à incompatível aumenta em função do tempo de reação. Em contraste, para o time Rival, uma tendência oposta foi encontrada, em que o efeito inibitório se torna mais forte para as respostas mais lentas. Sugere-se que a AffSCt é uma tecnologia poderosa para investigar comportamentos de aproximação/afastamento, podendo ser útil na avaliação diagnóstica e acompanhamento terapêutico de transtornos emocionais e comportamentais, como o de ansiedade generalizada, síndrome de pânico e transtorno do déficit de atenção/hiperatividade. Também são consideradas as aplicações potenciais em psicologia social e estudos de consumidor.(AU).

Los estímulos emocionales se procesan de manera muy eficiente e influyen en las respuestas fisiológicas y de comportamiento, así como en la atención, la percepción y la integración sensorio-motora. En un trabajo previo, que presentó un nuevo paradigma, la tarea afectiva de compatibilidad espacial (AffSCt), para estudiar si la valencia afectiva de los estímulos influyen en los efectos de la compatibilidad espacial. Mediante el uso de las figuras de los jugadores de fútbol de los equipos favorito e rival como estímulos positivo y negativo de valencia, respectivamente, se observó un efecto ordinario de compatibilidad espacial para el equipo favorito y un efecto invertido para el equipo rival. En este estudio, hemos examinado la evolución temporal de los efectos inhibitorios y facilitatorio de la valencia emocional por el uso de la Vincentización. Hemos encontrado que, para el equipo favorito, el efecto facilitatorio aumenta para la condición compatible, respecto la incompatible, con el tiempo de eacción. En contraste, para el equipo rival, una tendencia inversa se encontró, en el que el efecto inhibidor se vuelve más fuerte para las respuestas más lentas. Se sugiere que AffSCt es una poderosa tecnología para investigar los comportamientos de aproximación/retirada que puede ser útil para diagnosticar y seguir el tratamiento de trastornos afectivos y conductuales como ansiedad, pánico y déficit de atención/trastorno de hiperactividad. También son consideradas aplicaciones potenciales del método en la psicología social y en los estudios de consumo.(AU).

Affective spatial compatibility task(AFFSCT): theory and applications / Tarefa de compatibilidade espacial afetiva (TCEA): teoria e aplicações / Tarea de compatibilidad espacial afectiva (TCEA): teoría y aplicaciones

Emotional stimuli are processed very efficiently, influencing physiological and behavioral responses as well as attention, perceptual processes and sensory-motor integration. In a previous work, we introduced a new paradigm, the Affective Spatial Compatibility task (AffSCt), to study whether the affective valence of the stimulus influences spatial compatibility effects. By using figures of soccer players of Favorite and Rival Teams as positive and negative valence stimuli, we found a normal Spatial Compatibility effect for the Favorite team and a reversed one for the Rival team. Here, we analyzed the time course of inhibitory and facilitatory effects of emotional valence by the Vincentization method. We found that for Favorite team, the facilitatory effect for the compatible condition, as compared to the incompatible one, increases as a function of the reaction time. In contrast, for Rival team, an opposite trend was found, in which inhibitory effect beEmotional stimuli are processed verycomes stronger for slower responses. We suggest that AffSCt is a powerful technology for investigating approach/avoidance effects and that it may be useful for diagnosing and following up the treatment of affective and behavioral disorders, such as anxiety, panic and ADHD. Potential applications in social psychology and consumer studies are also considered.

Os estímulos emocionais são processados de forma muito eficiente, influenciando as respostas fisiológicas e comportamentais, bem como a atenção, a percepção e a integração sensório-motora. Em um trabalho anterior, propusemos um novo paradigma, a Tarefa Afetiva de Compatibilidade Espacial (AffSCt), para estudar se a valência afetiva do estímulo influenciaria os efeitos de compatibilidade espacial. Ao usarmos figuras de jogadores de futebol dos times Favorito e Rival como estímulos de valência positiva e negativa, respectivamente, encontramos um efeito de compatibilidade espacial normal para o time Favorito e um invertido para o time Rival. No presente trabalho, foi analisado o desenvolvimento temporal dos efeitos inibitórios e facilitatórios da valência emocional pelo método da Vincentização. Descobrimos que, para o time Favorito, o efeito facilitatório na condição compatível em relação à incompatível aumenta em função do tempo de reação. Em contraste, para o time Rival, uma tendência oposta foi encontrada, em que o efeito inibitório se torna mais forte para as respostas mais lentas. Sugere-se que a AffSCt é uma tecnologia poderosa para investigar comportamentos de aproximação/afastamento, podendo ser útil na avaliação diagnóstica e acompanhamento terapêutico de transtornos emocionais e comportamentais, como o de ansiedade generalizada, síndrome de pânico e transtorno do déficit de atenção/hiperatividade. Também são consideradas as aplicações potenciais em psicologia social e estudos de consumidor.

Los estímulos emocionales se procesan de manera muy eficiente e influyen en las respuestas fisiológicas y de comportamiento, así como en la atención, la percepción y la integración sensorio-motora. En un trabajo previo, que presentó un nuevo paradigma, la tarea afectiva de compatibilidad espacial (AffSCt), para estudiar si la valencia afectiva de los estímulos influyen en los efectos de la compatibilidad espacial. Mediante el uso de las figuras de los jugadores de fútbol de los equipos favorito e rival como estímulos positivo y negativo de valencia, respectivamente, se observó un efecto ordinario de compatibilidad espacial para el equipo favorito y un efecto invertido para el equipo rival. En este estudio, hemos examinado la evolución temporal de los efectos inhibitorios y facilitatorio de la valencia emocional por el uso de la Vincentización. Hemos encontrado que, para el equipo favorito, el efecto facilitatorio aumenta para la condición compatible, respecto la incompatible, con el tiempo de eacción. En contraste, para el equipo rival, una tendencia inversa se encontró, en el que el efecto inhibidor se vuelve más fuerte para las respuestas más lentas. Se sugiere que AffSCt es una poderosa tecnología para investigar los comportamientos de aproximación/retirada que puede ser útil para diagnosticar y seguir el tratamiento de trastornos afectivos y conductuales como ansiedad, pánico y déficit de atención/trastorno de hiperactividad. También son consideradas aplicaciones potenciales del método en la psicología social y en los estudios de consumo.

Independence of egocentric and exocentric direction processing in visual space

One major issue concerning investigations of visual perception is determination of the geometrical properties of visual space. To address this issue, one must determine the relationships between geometrical features of visual space, distance, direction, angle, and size. Consistent evidence indicates that visual angle is a determinant of perceived exocentric distance. Previous evidence suggests that exocentric distance and direction are hierarchically processed, with distance preceding direction. The present study investigated the relationship between the perceptual processing of egocentric direction and exocentric direction using a task that independently provides both perceptual variables in a single judgment. The results indicated that egocentric directions were systematically overestimated, and this was not caused by either the global shape of the layout or leg length effects. Exocentric directions presented a discontinuous pattern of overestimation of smaller angles that were subtended by radial orientations and accuracy of right angles that were subtended by horizontal orientations. This could be explained by the anisotropy of visual space, a well-established phenomenon from visual space studies. The analysis of the association between the processing of these two variables revealed independence between them in which exocentric direction processing did not depend on the processing of egocentric direction processing, and vice versa. The present results and prior evidence converge on the notion of hierarchical processing in which the visual system processes the egocentric distance of objects followed by exocentric distance processing and subsequent processing. The precise positions of egocentric and exocentric directions in this chain of processing remain to be determined.

Effects of affective valence on a mixed Spatial Correspondence Task: a reply to Proctor (2013)

The present study investigated the influence of emotional valence on the spatial stimulus-key location correspondence effect in three experiments using the Affective Spatial Correspondence task (AffSCt). We initially reanalyzed the results of Conde et al. (2011) according to the model proposed by Proctor (2013). In that study, compatible and incompatible responses were chosen according to the participants' team preference. In one block, the volunteers had to press a key on the same side for the Favorite team and on the opposite side for the Rival team. In another block, a reverse code was used. We found that responses were faster for the Favorite-compatible/Rival-incompatible condition (614 ms) compared with the Favorite-incompatible/Rival-compatible condition (691 ms). The same experimental arrangement was replicated in another Brazilian city, and similar results were found. Additionally, we employed non-affective "fake" soccer teams as a control condition, and no mapping-rule effect was observed. Finally, a final experiment that used the same design but different non-affective stimuli (yellow and blue bars) was performed to provide further evidence that the valence effect in the present experimental paradigm only occurs with affective stimuli. As expected, non-affective stimuli did not produce an overall advantage for any mapping rules, corroborating earlier findings with similar mixed designs. The results confirmed the previous findings and validity of the AffSCt as a methodology to investigate the effects of emotional valence on stimulus-response correspondence. However, we are unable to provide a conclusive explanation to support the several hypotheses proposed previously in our paper and by Proctor (2013).(AU)

Effects of affective valence on a mixed Spatial Correspondence Task: a reply to Proctor (2013)

The present study investigated the influence of emotional valence on the spatial stimulus-key location correspondence effect in three experiments using the Affective Spatial Correspondence task (AffSCt). We initially reanalyzed the results of Conde et al. (2011) according to the model proposed by Proctor (2013). In that study, compatible and incompatible responses were chosen according to the participants' team preference. In one block, the volunteers had to press a key on the same side for the Favorite team and on the opposite side for the Rival team. In another block, a reverse code was used. We found that responses were faster for the Favorite-compatible/Rival-incompatible condition (614 ms) compared with the Favorite-incompatible/Rival-compatible condition (691 ms). The same experimental arrangement was replicated in another Brazilian city, and similar results were found. Additionally, we employed non-affective "fake" soccer teams as a control condition, and no mapping-rule effect was observed. Finally, a final experiment that used the same design but different non-affective stimuli (yellow and blue bars) was performed to provide further evidence that the valence effect in the present experimental paradigm only occurs with affective stimuli. As expected, non-affective stimuli did not produce an overall advantage for any mapping rules, corroborating earlier findings with similar mixed designs. The results confirmed the previous findings and validity of the AffSCt as a methodology to investigate the effects of emotional valence on stimulus-response correspondence. However, we are unable to provide a conclusive explanation to support the several hypotheses proposed previously in our paper and by Proctor (2013)...

Priming effect of figures that represent external objects or human body parts

A visual stimulus (e.g., a letter, word, or object) may have a lasting effect on the processing of subsequent stimuli. The present study verified the priming effect of a figure (i.e., five-petal daisy) on manual reaction time (MRT) to another equal or different five-petal daisy. Two distinct groups were tested. One group was instructed that the five-petal daisy represented a human hand. The other group was instructed that the five-petal daisy represented a flower. The figures in the pairs of stimuli could share or not share some features such as handedness and view. In both groups, after being informed whether the five-petal daisy represented a flower or human hand, an uninformative flower was presented for 200 ms in the center of the screen. After 1000 ms, a second flower was presented in the same location until the observer responded by pressing a left or right switch. The results showed that prior presentation of the five-petal daisy affected MRT only when the figure represented a human hand. Furthermore, an opposite effect of view on MRT was found. The shorter MRT to the back (dorsal) view of the figure that represented a human hand could be attributable to a faster response to the dorsal view of a hand figure made with a prone posture of the participants' hand than to a front (palm) view. The longer MRT to the back view of the figure that represented a flower may be due to a mental rotation of the object along its vertical axis before selecting the correct response because the response was based on the position of the asymmetrical petal in the canonical front view of the daisy.(AU)

Priming effect of figures that represent external objects or human body parts

A visual stimulus (e.g., a letter, word, or object) may have a lasting effect on the processing of subsequent stimuli. The present study verified the priming effect of a figure (i.e., five-petal daisy) on manual reaction time (MRT) to another equal or different five-petal daisy. Two distinct groups were tested. One group was instructed that the five-petal daisy represented a human hand. The other group was instructed that the five-petal daisy represented a flower. The figures in the pairs of stimuli could share or not share some features such as handedness and view. In both groups, after being informed whether the five-petal daisy represented a flower or human hand, an uninformative flower was presented for 200 ms in the center of the screen. After 1000 ms, a second flower was presented in the same location until the observer responded by pressing a left or right switch. The results showed that prior presentation of the five-petal daisy affected MRT only when the figure represented a human hand. Furthermore, an opposite effect of view on MRT was found. The shorter MRT to the back (dorsal) view of the figure that represented a human hand could be attributable to a faster response to the dorsal view of a hand figure made with a prone posture of the participants' hand than to a front (palm) view. The longer MRT to the back view of the figure that represented a flower may be due to a mental rotation of the object along its vertical axis before selecting the correct response because the response was based on the position of the asymmetrical petal in the canonical front view of the daisy.

Efeito priming entre figuras de partes do corpo / The priming effect with pictures of body parts / El efecto priming entre figuras de las partes de lo cuerpo

Um estímulo visual (letra, palavra ou objeto) pode ter um efeito duradouro sobre o processamento de estímulos subsequentes. Neste trabalho, investigamos o efeito priming de figuras de mãos humanas (esquerda/direita, vista palmar/dorsal) sobre o Tempo de Reação Manual (TRM) em uma tarefa usando as mesmas figuras como estímulo alvo. Os pares de figuras podiam ser iguais ou não, de acordo com parâmetros como lateralidade ou vista. Três experimentos foram realizados (lateralidade, vista e cor). Neles, a figura de uma mão não-informativa era apresentada por 200 ms no centro de uma tela de computador. Após 1000ms, uma segunda mão era apresentada no mesmo local até a resposta, a qual consistia em pressionar o interruptor esquerdo ou o direito dependendo da lateralidade (Exp. I), da vista(Exp. II) ou da cor (Exp. III) do estímulo alvo. Os resultados mostraram que a apresentação prévia da figura de uma mão influencia o TRM ao segundo estímulo apenas quando a seleção da resposta é baseada em uma característica corporal (lateralidade ou vista).(AU)

The previous presentation of a visual stimulus (letter, word, and object) can have a lasting effect on the visual processing of subsequent stimuli. Here, we investigated the priming effect of drawings of the human hand (left/right hand, back/palm view) on the Manual Reaction Times (MRT) in a task using the same drawings as test stimuli. In a given trial, the two drawings could be matched (or not) for parameters such as laterality or view. Three experiments were performed exploring combinations of the parameters above. In all experiments, a non-informative drawing appeared for 200ms in a computer display and 1000ms later a second drawing appeared at the same location and remained on until the right or left switch was pressed to indicate the laterality (Exp. I), view (Exp. II) or color(Exp. III) of the target stimulus. The results show that presentation of the picture of a human hand influences MRTs to the second stimulus only when response selection is based on a body feature (handedness or view).(AU)

Un estímulo visual (letra, palabra o objeto) puede tener un efecto duradero en el procesamiento de los estímulos posteriores. En este estudio, hemos investigado el efecto priming de las figuras de manos humanas (izquierda/derecha, vista palmar/dorsal) en el Tiempo de Reacción Manual (TRM) en una tarea utilizando las mismas figuras como estímulo objetivo. Los pares de figuras pueden ser iguales o no, de acuerdo a parámetros tales como la lateralidad y vista. Tres experimentos se llevaron a cabo (lateralidad, vista y color). En los experimentos, la figura de una mano non informativa se presentó durante 200 ms en el centro de una pantalla del computador. Después de 1000 ms, una segunda mano se presentó en el mismo lugar hasta una respuesta la cual consistia en presionar un interruptor izquierdo o uno derecho dependiendo de la lateralidad (Exp. I), de la vista (Exp. II), o del color (Exp. III) del estímulo objetivo. Los resultados mostraron que la presentación previa de la figura de una mano influencia en el TRM para el segundo estímulo sólo cuando la selección de respuesta se basa en una característica corporal (lateralidad o vista).(AU)

Efeito priming entre figuras de partes do corpo / The priming effect with pictures of body parts / El efecto priming entre figuras de las partes de lo cuerpo

Um estímulo visual (letra, palavra ou objeto) pode ter um efeito duradouro sobre o processamento de estímulos subsequentes. Neste trabalho, investigamos o efeito priming de figuras de mãos humanas (esquerda/direita, vista palmar/dorsal) sobre o Tempo de Reação Manual (TRM) em uma tarefa usando as mesmas figuras como estímulo alvo. Os pares de figuras podiam ser iguais ou não, de acordo com parâmetros como lateralidade ou vista. Três experimentos foram realizados (lateralidade, vista e cor). Neles, a figura de uma mão não-informativa era apresentada por 200 ms no centro de uma tela de computador. Após 1000ms, uma segunda mão era apresentada no mesmo local até a resposta, a qual consistia em pressionar o interruptor esquerdo ou o direito dependendo da lateralidade (Exp. I), da vista(Exp. II) ou da cor (Exp. III) do estímulo alvo. Os resultados mostraram que a apresentação prévia da figura de uma mão influencia o TRM ao segundo estímulo apenas quando a seleção da resposta é baseada em uma característica corporal (lateralidade ou vista).

The previous presentation of a visual stimulus (letter, word, and object) can have a lasting effect on the visual processing of subsequent stimuli. Here, we investigated the priming effect of drawings of the human hand (left/right hand, back/palm view) on the Manual Reaction Times (MRT) in a task using the same drawings as test stimuli. In a given trial, the two drawings could be matched (or not) for parameters such as laterality or view. Three experiments were performed exploring combinations of the parameters above. In all experiments, a non-informative drawing appeared for 200ms in a computer display and 1000ms later a second drawing appeared at the same location and remained on until the right or left switch was pressed to indicate the laterality (Exp. I), view (Exp. II) or color(Exp. III) of the target stimulus. The results show that presentation of the picture of a human hand influences MRTs to the second stimulus only when response selection is based on a body feature (handedness or view).

Un estímulo visual (letra, palabra o objeto) puede tener un efecto duradero en el procesamiento de los estímulos posteriores. En este estudio, hemos investigado el efecto priming de las figuras de manos humanas (izquierda/derecha, vista palmar/dorsal) en el Tiempo de Reacción Manual (TRM) en una tarea utilizando las mismas figuras como estímulo objetivo. Los pares de figuras pueden ser iguales o no, de acuerdo a parámetros tales como la lateralidad y vista. Tres experimentos se llevaron a cabo (lateralidad, vista y color). En los experimentos, la figura de una mano non informativa se presentó durante 200 ms en el centro de una pantalla del computador. Después de 1000 ms, una segunda mano se presentó en el mismo lugar hasta una respuesta la cual consistia en presionar un interruptor izquierdo o uno derecho dependiendo de la lateralidad (Exp. I), de la vista (Exp. II), o del color (Exp. III) del estímulo objetivo. Los resultados mostraron que la presentación previa de la figura de una mano influencia en el TRM para el segundo estímulo sólo cuando la selección de respuesta se basa en una característica corporal (lateralidad o vista).

One-dimensional and multi-dimensional studies of the exocentric distance estimates in frontoparallel plane, virtual space, and outdoor open field.

The aim of this study is twofold: on the one hand, to determine how visual space, as assessed by exocentric distance estimates, is related to physical space. On the other hand, to determine the structure of visual space as assessed by exocentric distance estimates. Visual space was measured in three environments: (a) points located in a 2-D frontoparallel plane, covering a range of distances of 20 cm; (b) stakes placed in a 3-D virtual space (range = 330 mm); and (c) stakes in a 3-D outdoors open field (range = 45 m). Observers made matching judgments of distances between all possible pairs of stimuli, obtained from 16 stimuli (in a regular squared 4 x 4 matrix). Two parameters from Stevens' power law informed us about the distortion of visual space: its exponent and its coefficient of determination (R2). The results showed a ranking of the magnitude of the distortions found in each experimental environment, and also provided information about the efficacy of available visual cues of spatial layout. Furthermore, our data are in agreement with previous findings showing systematic perceptual errors, such as the further the stimuli, the larger the distortion of the area subtended by perceived distances between stimuli. Additionally, we measured the magnitude of distortion of visual space relative to physical space by a parameter of multidimensional scaling analyses, the RMSE. From these results, the magnitude of such distortions can be ranked, and the utility or efficacy of the available visual cues informing about the space layout can also be inferred.

Distance perception in a natural outdoor setting: is there a developmental trend to overconstancy?

The main purpose of the present study was to investigate whether in natural environment, using very large physical distances, there is a trend to overconstancy for distance estimates during development. One hundred and twenty-nine children aged 5 to 13 years old and twenty-one adults (in a control group), participated as observers. The observer's task was to bisect egocentric distances, ranging from 1.0 to 296.0 m, presented in a large open field. The analyses focused on two parameters, constant errors and variable errors, such as measuring accuracy and precision, respectively. A third analysis focused on the developmental pattern of shifts in constancy as a function of age and range of distances. Constant error analysis showed that there are two relevant parameters for accuracy, age, and range of distances. For short distances, there are three developmental stages: 5-7 years, when children have unstable responses, 7-11, underconstancy, and 13 to adulthood, when accuracy is reached. For large distances, there is a two-stage development: 5-11 years, with severe underconstancy, and beyond this age, with mild underconstancy. Variable errors analyses indicate that precision is noted for 7 year-old children, independently of the range of distances. The constancy analyses indicated that there is a shift from constancy (or slightly overconstancy) to underconstancy as a function of physical distance for all age groups. The age difference is noted in the magnitude of underconstancy that occurs in larger distances, where adults presented lower levels of underconstancy than children. The present data were interpreted as due to a developmental change in cognitive processing rather than to changes in visual space perception.

One-dimensional and multi-dimensional studies of the exocentric distance estimates in frontoparallel plane, virtual space, and outdoor open field

The aim of this study is twofold: on the one hand, to determine how visual space, as assessed by exocentric distance estimates, is related to physical space. On the other hand, to determine the structure of visual space as assessed by exocentric distance estimates. Visual space was measured in three environments: (a) points located in a 2-D frontoparallel plane, covering a range of distances of 20 cm; (b) stakes placed in a 3-D virtual space (range ≈ 330 mm); and (c) stakes in a 3-D outdoors open field (range = 45 m). Observers made matching judgments of distances between all possible pairs of stimuli, obtained from 16 stimuli (in a regular squared 4 × 4 matrix). Two parameters from Stevens' power law informed us about the distortion of visual space: its exponent and its coefficient of determination (R2). The results showed a ranking of the magnitude of the distortions found in each experimental environment, and also provided information about the efficacy of available visual cues of spatial layout. Furthermore, our data are in agreement with previous findings showing systematic perceptual errors, such as the further the stimuli, the larger the distortion of the area subtended by perceived distances between stimuli. Additionally, we measured the magnitude of distortion of visual space relative to physical space by a parameter of multidimensional scaling analyses, the RMSE. From these results, the magnitude of such distortions can be ranked, and the utility or efficacy of the available visual cues informing about the space layout can also be inferred (AU)

En este estudio se pretendía cubrir un doble objetivo. Por un lado, determinar cómo el espacio visual, evaluado en términos de estimaciones de distancias exocéntricas, se corresponde con el espacio físico. Y, por otro lado, determinar la estructura del espacio visual a partir de las mismas estimaciones de distancias. Para ello, registramos la respuesta (métrica) de los observadores en tres entornos espaciales: (a) puntos localizados en un plano 2-D (frontoparalelo) en un rango de distancias de 20 cm; (b) estacas vistas esteroscopicamente y situadas en un espacio virtual 3-D (rango de 33 cm); y (c) estacas físicas dispuestas en un espacio abierto exterior (rango de 45 m). Los observadores hicieron juicios de emparejamiento de distancias entre todos los posibles pares que se podían formar con 16 estacas (dispuestas en una matriz cuadrada regular de 4 filas × 4 columnas). Utilizamos dos parámetros de la ley potencial de Stevens, que nos informaron de la distorsión percibida del espacio visual: el exponente y el coeficiente de determinación (R2). Los resultados permitieron ordenar la magnitud de la distorsión encontrada en cada entorno experimental, proporcionando información sobre la utilidad y eficacia de las claves de profundidad disponibles. Nuestros datos concuerdan con los obtenidos en estudios previos en mostrar una cierta anisotropía espacial que difiere en cada entorno. Adicionalmente, aplicamos el escalamiento multidimensional y medimos la distorsión a través del RECM, lo que también nos permitió ordenar la magnitud de las distorsiones en cada contexto, así como la eficacia de las claves visuales de distancia (AU)

Distance perception in a natural outdoor setting: is there a developmental trend to overconstancy?

The main purpose of the present study was to investigate whether in natural environment, using very large physical distances, there isa trend to over constancy for distance estimates during development. One hundred and twenty-nine children aged 5 to 13 years old and twenty-one adults (in a control group), participated as observers. The observer’s task was to bisect egocentric distances, ranging from 1.0 to 296.0 m, presented in a large open field. The analyses focused on two parameters, constant errors and variable errors, such as measuring accuracy and precision, respectively. A third analysis focused on the developmental pattern of shifts in constancy as a function of age and range of distances. Constant error analysis showed that there are two relevant parameters for accuracy, age, and range of distances. For short distances, there are three developmental stages: 5-7 years, when children have unstable responses, 7-11, under constancy, and 13 to adulthood, when accuracy is reached. For large distances, there is a two-stage development: 5-11 years, with severe under constancy, and beyond this age, with mild under constancy. Variable errors analyses indicate that precision is noted for 7 year-old children, independently of the range of distances. The constancy analyses indicated that there is a shift from constancy (or slightly over constancy) to under constancy as a function of physical distance for all age groups. The age difference is noted in the magnitude of under constancy that occurs in larger distances, where adults presented lower levels of under constancy than children. The present data were interpreted as due to a developmental change in cognitive processing rather than to changes in visual space perception (AU)

El principal objetivo de este estudio fue investigar si en un medio natural, empleando distancias físicas muy grandes, hay una tendencia a sobre-constancia para las estimaciones de distancias durante el desarrollo evolutivo. Participaron como observadores 129 niños de edades entre 5 y 13 años y 21 adultos (en un grupo control). La tarea de los observadores consistió en biseccionar unas distancias egocéntricas, que variaban entre 1,0 y 296,0 m, presentadas en un gran campo abierto. El análisis se centró en dos parámetros, error constante y error variable, de la exactitud y precisión de medida, respectivamente. Un tercer análisis se centró en el patrón evolutivo de cambios en la constancia en función de la edad y el rango de distancias. El análisis de los errores constantes mostró que hay dos parámetros relevantes para la precisión, edad y rango de distancias. Para distancias cortas, hay tres fases evolutivas: 5-7 años, cuando los niños dan respuestas inestables, 7-11, infra-constancia, y 13 años hasta la adultez, cuando alcanzan la exactitud (constancia). Para las distancias largas, hay un desarrollo de dos fases: 5-11 años, con infra-constancia severa, y más allá de esta edad, con ligera infraconstancia. El análisis del error variable indica que se alcanza precisión a partir de 7 años, con independencia del rango de distancias. En análisis de la constancia indica que existe un cambio desde la constancia (o una ligera sobre-constancia) a infra-constancia en función de la distancia física para todos los grupos de edad. La diferencia de edad se nota en la magnitud de la infra-constancia que ocurre en las distancias más largas, donde los adultos presentaban niveles menores de infra-constancia que los niños. Estos datos se interpretan como debidos a un cambio evolutivo en el procesamiento cognitivo más que a cambios en la percepción visual del espacio (AU)

Visual angle as determinant factor for relative distance perception

Visual angles are defined as the angle between line of sight up to the meanpoint of a relative distance and the relative distance itself. In one experiment,we examined the functional aspect of visual angle in relative distanceperception using two different layouts composed by 14 stakes, one of themwith its center 23 m away from the observation point, and the other 36 maway from the observation point. Verbal reports of relative distance weregrouped in 10 categories of visual angles. Results indicated visual angle as adeterminant factor for perceived relative distance as observed in the absenceof perceptual errors to distances with visual angle equal or larger than 70degrees that could be attributed to a combination of sources of visualinformation. Another finding showed a possible intrusion of non-perceptualfactors (observer’s tendencies), leading to compressed estimates to relativedistances with visual angles smaller than 70 degrees

Um invariante no controle da percepção e ação em tarefas de bissecção / Perception-action interaction and bissection

Diversos estudos empregando ações visualmente dirigidas como indicadores da distância percebida demonstraram que as pessoas podem caminhar acuradamente para alvos distantes em até 22m. Estes resultados, somados aos relacionados com medidas perceptuais de distância percebida, demonstram que estas respostas são controladas por uma única variável interna, denominada de localização visualmente percebida. No presente estudo, comparamos os desempenhos em tarefas de bissecção, realizadas por caminhada visualmente dirigida, ou por emparelhamento perceptual. Os observadores (N=20) caminharam ou ajustaram a posição de uma ponteira ao ponto médio da distância egocêntrica de um alvo (5,10 ou 15 m), sob observação binocular. Os resultados indicaram acurácia em ambas respostas, sem diferenças significativas entre elas, o que sustenta a hipótese de uma única variável interna controlando ação e percepção. Este invariante pode ser determinado por um conjunto ponderado de fontes de informação (AU)

Um invariante no controle da percepção e ação em tarefas de bissecção / Perception-action interaction and bissection

Diversos estudos empregando ações visualmente dirigidas como indicadores da distância percebida demonstraram que as pessoas podem caminhar acuradamente para alvos distantes em até 22m. Estes resultados, somados aos relacionados com medidas perceptuais de distância percebida, demonstram que estas respostas são controladas por uma única variável interna, denominada de localização visualmente percebida. No presente estudo, comparamos os desempenhos em tarefas de bissecção, realizadas por caminhada visualmente dirigida, ou por emparelhamento perceptual. Os observadores (N=20) caminharam ou ajustaram a posição de uma ponteira ao ponto médio da distância egocêntrica de um alvo (5,10 ou 15 m), sob observação binocular. Os resultados indicaram acurácia em ambas respostas, sem diferenças significativas entre elas, o que sustenta a hipótese de uma única variável interna controlando ação e percepção. Este invariante pode ser determinado por um conjunto ponderado de fontes de informação

Perceptual constancy in judgments of egocentric distance: prevailing binocular information

Binocular cues were considered the prevailing on specifying depth since the beginning of vision research. In the present study, two perceptual responses, the classical verbal report and a more recent method, open-loop walking, were used to assess the role of binocular information for egocentric distance perception. In two cue conditions environments, full- and reduced-cue, observers judge and walked egocentric distances of stimuli presented at eye-level, under binocular or monocular viewing. Results indicated perceptual constancy for open-loop walking and binocular responses, as well as poor performances under strong degradation on visual information (reduced-cue under strong monocular viewing), thus presenting evidence to support the fundamental role of binocular information on perception of egocentric distances. Besides that, visually directed actions could be adequate measures of perceived distance, with a better reliability than verbal report, since they were quite free of intrusion of inferential processes and perceptual tendencies. In addition, reduced head movements, side-to-side as well as back and forth deflexion movements, could have contributed to a near perfect coupling between binocular disparity information and open-loop walking responses.