The focus here is on the paradoxical finding that whereas visually perceived egocentric distance is proportional to physical distance out to at least 20 m under full-cue viewing, there are large distortions of shape within the same range, reflecting a large anisotropy of depth and frontal extents on the ground plane. Three theories of visual space perception are presented, theories that are relevant to understanding this paradoxical result. The theory by Foley, Ribeiro-Filho, and Da Silva is based on the idea that when the visual system computes the length of a visible extent, the effective visual angle is a non-linear increasing function of the actual visual angle. The theory of Durgin and Li is based on the idea that two angular measures, optical slant and angular declination, are over-perceived. The theory of Ooi and He is based on both a default perceptual representation of the ground surface in the absence of visual cues and the "sequential surface integration process" whereby an internal representation of the visible ground surface is constructed starting from beneath the observer's feet and extending outward.

Esta pesquisa comparou a acurácia da atualização espacial de alvos situados à frente com a de alvos situados atrás do observador. O participante observava um alvo no solo distante vários metros dele e então, sem a visão, andou de lado ao longo de uma corda-guia enquanto tentava atualizar mentalmente a localização do alvo. Em algumas tentativas, a localização do alvo esteve à frente do observador e, em outras tentativas, a localização do alvo foi atrás. Os participantes respondiam encarando a localização atualizada do alvo com os olhos fechados. Os resultados indicaram que as pessoas são capazes de atualizar a localização de alvos localizados atrás delas aproximadamente tão bem quanto localizações de alvos à frente delas.

This research compared the accuracy of spatial updating of targets in front with that of targets behind. The participant viewed a target on the ground several meters away and then, without vision, sidestepped along a guide rope while trying to mentally update the location of the target. On some trials, the target location was in front as the person sidestepped and, on other trials, the target location was behind. Participants responded by facing the updated target location with eyes closed. The results indicate that people are able to update target locations behind them very nearly as well as target locations in front.

Este estudo apresenta uma breve visão geral da percepção visual do espaço. Começa relatando a significância da percepção visual do espaço para questões mais amplas na filosofia e na ciência, e observa que a apreciação da percepção visual do espaço como um tópico científico é evitada pelo realismo ingênuo. A segunda seção relata o interesse perene na fenomenologia do espaço visual e foca em uma questão, a dissociação entre localização percebida e forma percebida no espaço visual. A última seção discute três concepções de como a visão controla a ação, com atenção especial para o papel do espaço visual.

This article presents a brief overview of visual space perception. It begins by noting the significance of visual space perception to broader issues in philosophy and science and observes that the appreciation of visual space perception as a scientific topic is impeded by naïve realism. The second section notes the longstanding interest in the phenomenology of visual space and focuses on one issue, the dissocation between perceived location and perceived shape in visual space. The last section discusses three conceptions of how vision controls action, with special attention to the role of visual space.