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Proceedings Paper

Parallel, semiparallel, and serial processing of visual hyperacuity
Author(s): Manfred W. Fahle
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Paper Abstract

Humans can discriminate between certain elementary stimulus features in parallel, i.e., simultaneously over the visual field. I present evidence that, in man, vernier rnisalignments in the hyperacuity-range, i.e., below the photoreceptor diameter, can also be detected in parallel. This indicates that the visUal system performs some form of spatial interpolation beyond the photoreceptor spacing simultaneously over the visual field. Vernier offsets are detected in parallel even when orientation cues are masked: deviation from straightness is an elementary feature of visual perception. However, the identification process, that classifies each vernier in a stimulus as being offset to the right (versus to the left) is serial and has to scan the visual field sequentially if orientation cues are masked. Therefore, reaction times and thresholds in vernier acuity tasks increase with the number of verniers presented simultaneously if classification of different features is required. Furthermore, when approaching vernier threshold, simple vernier detection is no longer parallel but becomes partially serial, or semi-parallel.

Paper Details

Date Published: 1 October 1990
PDF: 13 pages
Proc. SPIE 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications, (1 October 1990);
Show Author Affiliations
Manfred W. Fahle, Massachusetts Institute of Technology (United States)

Published in SPIE Proceedings Vol. 1249:
Human Vision and Electronic Imaging: Models, Methods, and Applications
Bernice E. Rogowitz; Jan P. Allebach, Editor(s)

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