The role of active exploration in the visual perception of material qualities
Mon-H4-Talk 2-1702
Presented by: Katja Doerschner
Image motion conveys crucial information about material properties (e.g. Doerschner et al. 2011, Paulun et al. 2017), and motion signals are generated for instance, when we actively explore and manipulate an object: we tend to indent soft things, run our hands through sand or stroke fuzzy plush. Little is known about how this active exploration affects how a visual material quality is perceived, or conversely, if visual material properties modulate the exploration process. We investigated these questions using a novel active exploration paradigm in Virtual Reality combined with real-time hand tracking in an experiment where participants had to either match the glossiness or the lightness of a novel-shaped object to a reference scale. Participants could either move the object with their hand or look at it passively while forming their judgments. In the analysis, we contrasted 1) perception between passive and active conditions and 2) the time spent and the amount of exploring between the two material judgments tasks. We found that participants (N=20) differed in exploration behaviors between the two perceptual tasks: during gloss judgments, they explored objects longer and to a greater extent, than during lightness judgments. A potential explanation of the increased exploration could be that participants actively produced highlight motion, which would lead to a more robust estimate of glossiness. The found increase in perceived gloss in the active condition would be consistent with this interpretation. For the lightness task, we did not find perceptual differences perceived active and passive conditions.
Keywords: active exploration, material perception