Scales for Perceived Egocentric Distance in a Large Open Field: Comparison of Three Psychophysical Methods

Silva, José Aparecido da

doi:10.2307/1422771

Cited by 154 publications

(128 citation statements)

References 52 publications

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“…We fitted a power function to the perceived distance data. The obtained exponent of the power function was .910, which was comparable to the results of previous studies (e.g., Da Silva, 1985;Loomis et al, 1992).…”

Section: Actual Environmentsupporting

confidence: 91%

Verification of Emmert's Law in Actual and Virtual Environments

Nakamizo

Imamura

2004

J. Physiol. Anthropol.

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We examined Emmert's law by measuring the perceived size of an afterimage and the perceived distance of the surface on which the afterimage was projected in actual and virtual environments. The actual environment consisted of a corridor with ample cues as to distance and depth. The virtual environment was made from the CAVE of a virtual reality system. The afterimage, disc-shaped and one degree in diameter, was produced by flashing with an electric photoflash. The observers were asked to estimate the perceived distance to surfaces located at various physical distances (1 to 24 m) by the magnitude estimation method and to estimate the perceived size of the afterimage projected on the surfaces by a matching method. The results show that the perceived size of the afterimage was directly proportional to the perceived distance in both environments; thus, Emmert's law holds in virtual as well as actual environments. We suggest that Emmert's law is a specific case of a functional principle of distance scaling by the visual system.

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Section: Actual Environmentsupporting

confidence: 91%

Verification of Emmert's Law in Actual and Virtual Environments

Nakamizo

Imamura

2004

J. Physiol. Anthropol.

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“…Previous studies (e.g., Da Silva, 1985;Higashiyama, 1993) showed that the mean exponent of the power function fitted to the mean perceived distance obtained in the full-cue condition was between 0.85 and 0.97. The exponent of 0.916 obtained in the present study is within this range.…”

Section: Perceived Distancementioning

confidence: 88%

An Empirical Test of Formal Equivalence between Emmert's Law and the Size-Distance Invariance Hypothesis

Imamura

Nakamizo

2006

Span. J. Psychol.

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Emmert's law and the size-distance invariance hypothesis have been said to be formally equivalent, provided that Emmert's law means that the perceived size of an afterimage is proportional to the perceived distance of the projected surface of the afterimage. However, there have been very few studies that have attempted to verify this formal equivalence empirically. We measured both the perceived size and distance of afterimages and real objects with the same proximal size. Nineteen participants projected afterimages of 1 deg in visual angle on the wall located at distances of 1 to 23 meters from the participants. They also observed real objects, disc-shaped and made from a sheet of Styrofoam board, with the same proximal size as that of the afterimages, which were located at the same physical distances as those of the wall on which the afterimages were projected. Each participant reproduced the apparent sizes of the afterimages and real objects using the reproduction method and estimated the apparent distances using the magnitude estimation method. When the mean apparent sizes of the afterimages and real objects, represented as a function of apparent distance, were fitted to a linear function, the slopes for the afterimages and real objects did not differ significantly. These results are interpreted as evidence for the formal equivalence of Emmert's law and the size-distance invariance hypothesis. Keywords: Emmert's law, size-distance invariance hypothesis, afterimage, size perception, distance perception Es común considerar a la ley de Emmert y la hipótesis de la invarianza del tamaño-distancia como equivalentes formalmente. Para llegar a esta conclusión se parte de considerar que, al aplicar la ley de Emmert, el tamaño percibido de la postimagen es proporcional a la distancia percibida de la superficie en la que se proyecta. A pesar de lo anterior, muy pocos estudios han intentado verificar empíricamente esta equivalencia formal. En este trabajo se midió tanto el tamaño percibido como la distancia de postimágenes y de objetos reales con el mismo tamaño proximal. 19 participantes proyectaron postimágenes con un ángulo visual de 1 grado sobre una pared de 1 a 23 metros respecto a los participantes. Estos también observaron objetos reales, en forma de discos, hechos de una plancha de espuma Styrofoam, con el mismo tamaño proximal que el de las postimágenes, que se colocaron a las mismas distancias físicas que las de la pared sobre la que se proyectaron las postimágenes. Cada participante reprodujo los tamaños aparentes de las postimágenes y de los objetos reales usando el método de reproducción y estimó las distancias aparentes empleando el método de estimación de magnitudes. Cuando los tamaños medios aparentes de las postimágenes y de los objetos reales, representados en función de la distancia aparente, se ajustaron a una función lineal, las pendientes de las postimágenes y de los objetos reales no diferían significativamente. Estos resultados se interpretan como evidencia para la equivalencia formal de la ley ...

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“…As the amplitude factor of the stimulus may affect the value of the exponent of the power function and the scale stability, care was taken when designing the experiment (Bolanowski & Gescheider, 1991;Da Silva, 1985;Da Silva & Macedo, 1982;Krueger, 1989;Stevens & Guirao, 1963). The estimated magnitude of the distances among the stimuli of the configuration produced by the participants was used to estimate the exponents of the power function (Stevens, 1975).…”

Section: Part Amentioning

confidence: 99%

Influence of the Instructions on the Performance and Establishment of Memorization Strategies in Space Judgments

Rodrigues

Marques

2006

Span. J. Psychol.

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Studies of visual space perception have been assuming that people have an internal representation of the physical space that surrounds them. A variety of psychophysical procedures has been used in an attempt to measure the properties of visual space. The goal of the present study was to evaluate the accuracy of the mental representation and the strategies adopted to acquire and retain visuo-spatial information of a configuration as a function of two types of instructions. Thirty-eight undergraduate and graduate students participated in the study and were distributed in perceptive and mnemonic experimental conditions. The effect of the instructions (intentional and incidental) on the representation of the distances among the objects of the scene was estimated using exponents of power function, based on the reproduction of the distances among the stimuli of the scene. The results revealed that judgments made under intentional instructions were more frequently based on strategies related to the location of the stimuli, whereas judgments originating from incidental instructions were based on strategies related to the name of the stimuli. It was observed that the intentional instruction facilitated a more accurate mental representation of the observed experimental configuration, enhancing participants' performance. Keywords: instructions, strategies, visuo-spatial perception, mental representation, spatial configurationLos estudios sobre la percepción visual del espacio asumen que las personas tienen una representación interna del espacio físico que les rodea. Con la finalidad de medir las propiedades de tal percepción visual se han empleado distintos procedimientos psicofísicos. El propósito de este trabajo fue el de evaluar la precisión de la representación mental y de las estrategias adoptadas para adquirir y retener la información del espacio visible en función de dos tipos de instrucciones. Treinta y ocho estudiantes universitarios y licenciados participaron en el estudio, distribuyéndose en las condiciones experimentales perceptiva y mnemónica. Se estimó el efecto de las instrucciones (intencionales e incidentales) sobre la representación de las distancias entre los objetos del escenario empleando los exponentes de la función potencial, basado en la reproducción de las distancias entre los estímulos del escenario. Los resultados mostraron que los juicios realizados bajo instrucciones intencionales se basaban con mayor frecuencia en estrategias relacionadas con la ubicación de los estímulos, mientras que los juicios bajo instrucciones incidentales se basaban en estrategias relacionadas con el nombre de los estímulos. Se observó que las instrucciones intencionales facilitaron una representación mental más precisa de la configuración experimental observada, mejorando la ejecución de los participantes. Palabras clave : instrucciones, estrategias, percepción viso-espacial, representación mental, configuración espacial

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Scales for Perceived Egocentric Distance in a Large Open Field: Comparison of Three Psychophysical Methods

Cited by 154 publications

References 52 publications

Verification of Emmert's Law in Actual and Virtual Environments

Verification of Emmert's Law in Actual and Virtual Environments

An Empirical Test of Formal Equivalence between Emmert's Law and the Size-Distance Invariance Hypothesis

Influence of the Instructions on the Performance and Establishment of Memorization Strategies in Space Judgments

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