Walking through an aperture with visual information obtained at a distance

Abstract

The present study addressed whether visual information about the width of an aperture, obtained at a distance, would be sufficient to guide walking through the aperture without collision. For this purpose, we asked twelve young participants to walk while holding a 66-cm horizontal bar (bar length needs to be considered in order to perceive space necessary for crossing) and pass through an aperture without vision from 3 m in front of the aperture. Participants performed the tasks under each of four visual conditions, which differed in how vision was available: observation for 1.5 s while standing (static vision), observation during two forward steps and stopping (dynamic vision), observation during two forward steps and not stopping (dynamic vision with nonstop walking), and full vision. The results showed that, for narrow apertures (the widths were 0.8 and 1.0 times the bar length), the rate of collision without vision was about 40-50 %. This was mainly due to the maladaptive planning of body rotation. For the aperture 1.0 times the bar length, the percentage of trials with no body rotation was high, suggesting that at least some participants underestimated the space necessary for crossing. The location at which maximum body rotation occurred became farther from the obstacle, which may have been related to decreased movement speed. The availability of dynamic visual sampling during two forward steps did not contribute to improving collision avoidance. These results suggest that, while fundamental locomotor patterns are maintained even without online vision, both the underestimation of space required for crossing and the lack of fine-tuning of behavior prior to crossing increased collision rates.

An integrative model of visual control of action

“…Although, yet to be thoroughly investigated, this assertion must also deal with the fact that it is unlikely that every human behavior must be online controlled, considering our attentional limits. Several evidences showed that human locomotion performance remains unchanged under intermittent visual monitoring (Bigel & Ellard, 2000;Fukusima et al, 1997;Loomis et al, 1992;Matsushima et al, 2002;Muroi & Higuchi, 2017;Rieser et al, 1990;Thomson, 1983). These evidences advocate for an internal perceptual variable underlying action performance, favoring a model-based visual control of action, such as the one proposed here.…”

A systematic review of perception of affordances for the person-plus-object system

“…Finally, Muroi and Higuchi (2017) investigated perception of affordances for passing through an aperture while holding an object horizontally under different vision conditions-a static vision condition in which participants viewed the aperture at the start of the trial but had to pass through it with vision occluded, a full vision condition in which vision was never occluded, and two dynamic vision conditions in which participants were required to stop and start again after taking two steps and then pass through the aperture with or without vision occluded. They found that perception of affordances in this task depended on whether the task was performed continuously (i.e., without stopping) and whether (and when) vision was occluded while performing the task.…”

Haptic feedback intervention decreases the spatial margin when older adults walk through a narrow space

“…To examine this hypothesis, we selected a walking-through-an-aperture task in accordance with previous studies [ 13 , 20 , 21 ]. We required participants to hold a horizontal bar [ 22 , 23 ] in order to make the task relatively difficult, since it was hard for participants to improve their performance if the task was too simple.…”