Geometrical Features Underlying the Perception of Colinearity

Morgan, M. J. & Dillenburger, B. (2016). Geometrical Features Underlying the Perception of Colinearity. Vision Research, 128, pp. 83-94. doi: 10.1016/j.visres.2016.09.008

[img] Text - Accepted Version
Restricted to Repository staff only until 17 October 2017.
Available under License : See the attached licence file.

Download (1MB) | Request a copy
[img]
Preview
Text (Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence) - Other
Download (201kB) | Preview

Abstract

The magnitude of the Poggendorff bias in perceived collinearity was measured with a 2AFC task and roving pedestal, and was found to be in the region of 6–8 deg, within the range of previous estimates. Further measurements dissected the bias into several components: (1) The small (∼1 deg) repulsion of the orientation of the pointer from the parallel, probably localized in the part of the line near the intersection (2) A small (<1 deg) location bias affecting the intersection of pointers and inducing lines; and (3) A larger (>1 deg) bias in the orientation of virtual lines crossing the gap between two parallels, towards the orientation of the parallels, or equivalently (4) An orthogonal bias in actively constructing a virtual line across the gap. We conclude that orientation repulsion by itself is an inadequate explanation of the Poggendorff effect, and that a full explanation must take account of the way in which observers construct virtual lines in visual space in order to carry out elementary geometrical tasks such as extrapolation.

Item Type: Article
Additional Information: © 2016, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Uncontrolled Keywords: Spatial vision; Alignment acuity; Poggendorff
Subjects: R Medicine > RE Ophthalmology
Divisions: School of Health Sciences > Department of Optometry & Visual Science
URI: http://openaccess.city.ac.uk/id/eprint/15531

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics