Abstract
Background: Recently, we found that distance judgments made via blindwalking were larger in outdoor settings than indoors, but only when targets were seen through an aperture that occluded all but the region immediately around the target. Because the visual cues available through the aperture were roughly constant across settings, knowledge about the unseen setting presumably played a role. While shorter walked distances indoors may reflect a genuine perceptual bias associated with this knowledge, participants may simply tend to stop short when walking with walls nearby. Method: To test this, we compared distance estimates (blindwalking) and gestured size estimates--a response not constrained by walls--for indoor targets 2.5 – 5 m distant. Walking showed increased underestimation under aperture-restricted viewing than under unrestricted viewing (M = -20% vs. -7%); size gestures showed a similar pattern (M = -5% vs. 8%). This suggests that there is a perceptual component underlying the effects of aperture-restricted viewing; the physical constraints on walking imposed by the walls does not fully explain the effect. We next compared verbal reports of distance and gestured target size, manipulating setting (indoors / outdoors), under aperture-restricted viewing. This replicated our past blindwalking design, but with two responses not constrained by walls. Results: There were no indoor-outdoor effects on constant errors with either response type. Because we previously found increased undershooting with blindwalking when indoors under similar conditions, the lack of effect here may implicate a residual walking-specific output-related effect: in this view, under aperture-restricted viewing, the indoor setting is assumed to be small, but the aperture conceals the precise boundaries and this elicits conservative walking. Conclusions: Taken together, the results indicate that indoor/outdoor effects under aperture-restricted viewing—a condition that closely matches the visual cues available across settings--may reflect interactions between perceptual and output processes.
Meeting abstract presented at VSS 2016