Distortions of spatial perception due to the presence of objects
Date
2022
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Publisher
University of Delaware
Abstract
Many visual illusions affect the perception of size and distance. One such illusion – “object-based warping” (Vickery & Chun, 2010) – is a tendency to misjudge the distance between two targets due to the presence of a nearby object. In a series of experiments using a staircase procedure, we investigated two opposing effects within object-based warping – object-based compression (instances where the estimated distance is underestimated) and object-based expansion (instances where the estimated distance is overestimated). We mapped the extent of the distortion relative to the object: we explored the role the boundaries play in these illusions, and how progressive displacement congruent and incongruent with the main object axis affects the magnitude of distortion. Results indicated that displacement congruent with the main object axis strengthens object-based compression, while displacement incongruent with the main object axis reduces both illusions progressively. We tested whether the compression effect can be modulated via attention drawn by the saliency of the object (via the oddball status) and did not find any evidence for such modulation. We theorize about the potential sources of distortion within objects related to quadrants, edges, or medial-axis shape skeleton and discuss the limitations of these models based on the obtained results.
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Keywords
Attention, Illusion, Perception, Psychophysics, Vision