PubMed · 5774950
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A Robertson, S Fienberg. 1969-02-15. Parapsychology.. https://doi.org/10.1038/221687a0
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Our capacity to detect spatial misalignments a fraction of the distance between retinal receptors in the presence of image motion challenges our understanding of spatial vision. We find that vernier acuity, while robust to image translation, rapidly degrades during image rotation. This indicates that orientation is a critical cue utilized by the visual system in vernier acuity tasks. Moreover, vernier acuity is robust to translational motion only at high target strengths. Vernier acuity for translating 3-dot targets over midrange velocities can be predicted from vernier acuity data derived from static targets of different presentation durations. However, the degradation observed at higher velocities is greater than predicted. The high velocity degradation reveals that performance is limited by a 1 msec asynchrony sensitivity. The moving vernier stimulus appears to constitute an optimal configuration for the visual system to achieve a 1 msec asynchrony sensitivity by making use of an orientation cue.
A fundamental issue in the study of human vision is the accuracy with which observers can perceive the three-dimensional structures of objects in the environment. The formal mapping from physical to perceived space is considered as a geometric transformation, and the literature is reviewed to identify which aspects of object structure are systematically distorted by this transformation and which ones remain invariant. In the perceptual analysis of several different sources of optical information, including motion and stereo, both individually and in combination, there is a consistent pattern of results to indicate that perceived depth intervals are scaled differently from comparable intervals in either horizontal or vertical directions. These and other findings provide strong evidence that the relationship between physical and perceived space is noneuclidean, and that the three-dimensional structures of objects can appear systematically distorted even when viewed under full cue conditions.