December 2022
Volume 22, Issue 14
Open Access
Vision Sciences Society Annual Meeting Abstract  |   December 2022
A Person with Multiple Failures of Perceptual Inference
Author Affiliations
  • Allan C. Dobbins
  • Elizabeth G. Dobbins
    Samford University, Birmingham, AL, USA
Journal of Vision December 2022, Vol.22, 4252. doi:
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      Allan C. Dobbins, Elizabeth G. Dobbins; A Person with Multiple Failures of Perceptual Inference. Journal of Vision 2022;22(14):4252.

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      © ARVO (1962-2015); The Authors (2016-present)

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During an undergraduate Art and Perception class we encountered a student who, with no previous familiarity with the phenomena in question, failed to see the Kanizsa triangle and also failed to see phi motion. When shown web-based versions of these displays, her father perceived both the Kanizsa figure and apparent motion. Like the daughter, the mother did not see the Kanizsa figure but, unlike her daughter, did see apparent motion. On a subsequent visit to the laboratory the student was tested with a variety of visual displays including tests of motion, stereopsis, second order (disparity-derived) motion, and a variety of displays of discrete motion such as morphing (extrusion-like) motion and Kanizsa displays in which the Pacman-defined vertices of a triangle were modified so as to imply translation, expansion, or rotation. None of these were perceived as figures in motion. The student began wearing glasses at age two and was diagnosed as dyslexic in the first grade. Thanks to the early visual correction, her stereopsis is normal and she is able to correctly discriminate the direction of motion in a cyclopean grating in which the dynamic random dots did not move. The dissociation between continuous and discrete motion perception would seem to imply that they have a different physiological basis. The unusual combination of deficits in surface perception and apparent motion suggest a deficit in visual inference, and possibly a deficiency in recurrent or feedback connections among cortical areas.


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