RESUMO
In a three-dimensional (3D) world most saccades are made towards visual targets that are located at different distances. We previously demonstrated that gaze shifts within 3D space consist of two stages: a target saccade followed by a corrective saccade during gaze fixation that directs the eyes to the physical target location. We proposed that, by accurately positioning the eyes on the visual object, the visual system maintains an orderly representation of the visual world. In this study we used a double saccade experiment to assess the function of corrective saccades in humans. We found that, when a corrective eye movement occurred during fixation on the first target point, the direction of the second saccade towards the next target point was accurate. When a corrective saccade was absent, a directional error of the second target saccade was observed. This finding, which cannot be explained by current models of eye movement control, supports the idea of a two-step model in saccade programming. We suggest that the motor system sends a corollary discharge when programming a corrective saccade for maintaining an orderly representation of the visual world. In conclusion, our results indicate that corrective saccades have a role in programming target saccades within 3D space.
Assuntos
Fixação Ocular , Desempenho Psicomotor , Movimentos Sacádicos , Adulto , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino , Estimulação Luminosa , Psicofísica , Adulto JovemRESUMO
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.
RESUMO
This study aims to explore whether the implicit processing of emotional symbols related to patriotic feeling may exert some effects on attention. Here, we have conducted an experiment using two interrelated tasks. First, we use flags with different meanings to participants for measuring the strength of the emotional attentional blink (EAB) within a rapid serial visual presentation (RSVP) paradigm. Then, we use a "congruency judgments" subjective test, where we confront participants to judge the affinity between pairs of politician leaders and flags of different sign for community participants, while recording two physiological measures (Heart Rate Variance and Galvanic Skin Response) to evaluate the variations elicited by that confrontation. Results on the EAB task show a significant emotion induced blindness for emotional stimuli representing Catalan and Spanish patriotism (α = .05), while the effect does not appear for the stimulus representing neutral patriotism. The interaction "Flags x Patriotism" was significant, F(1, 51) = 4.62; p = .036; ηp2 = .083. Results on the second task show that measures derived from electrophysiological records are sensitive to patriotic feeling, both being complementary. In addition, by using measures of congruence, the "Leaders x Flags" interaction was significant, F(3.682, 125.204) = 53.55; p < .001; ηp2 = .612. Finally, a multiple linear regression model for each emotional inductor was verified for the Catalan case, using the EAB effect as criteria, R2Adjusted = .79; p < .001. Some theoretical and methodological aspects derived of this exploratory study are discussed.
Assuntos
Intermitência na Atenção Visual/fisiologia , Emoções/fisiologia , Resposta Galvânica da Pele/fisiologia , Frequência Cardíaca/fisiologia , Identificação Social , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Política , Espanha , Adulto JovemRESUMO
The major aim of this overview was the visual perception of egocentric (distance from an observer to a target) and exocentric distance (distance between two targets). We considered different issues concerning the relationship between perceived distance and physical distance, giving special attention to the theories, to the cues regarding distance, how perceived distances are measured, and the types of visual environments where the measuring of distances occurred. We concluded that the perceived distance does not reflect a simple transformation of its physical counterpart; rather, the mapping between perceived distance and physical distance depends substantially on the type of visual environments where distances are measured, and, on the cue combination available in these environments.
Assuntos
Percepção de Distância/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , HumanosRESUMO
In this study, we examined differences in dynamic visual acuity between elite and subelite water polo players and sedentary students. To measure dynamic visual acuity binocularly, we asked participants to indicate the orientation of a broken ring, similar to the Landolt C, which increased in size as it moved across a computer screen. Two different speeds, three possible trajectories, and two different levels of contrast were evaluated. There were statistically significant differences between elite players and sedentary students for each combination of speed, contrast, and trajectory. Elite players achieved better dynamic visual acuity scores, and results also improved for some combinations of speed, contrast, and trajectory. Comparison between elite and subelite groups failed to reveal any
Assuntos
Desempenho Atlético , Natação/fisiologia , Acuidade Visual , Análise de Variância , Feminino , Humanos , Masculino , Percepção de Movimento/fisiologia , Tempo de Reação , Comportamento Sedentário , Adulto JovemRESUMO
In the present paper, we review some programming languages and computer software used to investigate basic psychological processes. In the first section, we address the principles and logical structure of the most common programming languages (e.g. C, C++, Java, Matlab, R, Python), and in the second section we present some of their applications to psychological research. Finally, we discuss the importance of computer programming as a tool in the field of psychology and its relationship with technological innovation.
No presente artigo foram revisadas algumas linguagens de programação esoftwares usados na investigação dos processos psicológicos básicos. Na primeira seção, foram abordados os princípios e a estrutura lógica das linguagens mais comuns de programação (e.g. C, C++, Java, Matlab, R e Python), e na segunda seção foram apresentadas algumas de suas aplicações na pesquisa psicológica. Ao final, são discutidas a importância da programação como uma ferramenta no campo da psicologia e sua relação com a inovação tecnológica.
En el presente artículo revisamos algunos de los lenguajes de programación y programas informáticos utilizados en la investigación de los procesos psicológicos básicos. En la primera sección, abordamos los principios y la estructura lógica de los lenguajes más comunes de programación (e.g., C, C++, Java, Matlab, R, y Python), y en la segunda sección, presentamos algunas de sus aplicaciones en la investigación psicológica. Al final, discutimos la importancia de la programación como una herramienta en el campo de la psicología y su relación con la innovación tecnológica.
Assuntos
Desenvolvimento Tecnológico , Linguagens de Programação , SoftwareRESUMO
Nesta revisão, analisamos diferentes aspectos relacionados à métrica da percepcão visual. Atencão especial foi dada à mensuracão de distância egocêntrica (distância de um observador a um objeto) e à mensuracão de distância exocêntrica (distância entre dois objetos, ou partes de um objeto). Além disso, foram, brevemente, consideradas as teorias, a natureza dos indícios de distância, os tipos de indicadores de distância percebida, e os ambientes nos quais as distâncias são mensuradas. Concluímos que, a relacão entre distância percebida e distância real não reflete uma simples transformacão de sua contraparte física; em vez disso, esta relacão depende substancialmente do ambiente no qual as distâncias são estimadas bem como da combinacão de indícios de distância presente neste ambiente.