| Judging the shape of moving objects: discriminating dynamic angles. | |
| | |
MedLine Citation:
|
PMID: 19146339 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Studies of shape perception have typically focused on static shapes. Studies of motion perception have mainly investigated speed and direction. None have addressed performance for judging the shape of moving objects. We investigated this by determining the discrimination of geometric angles under various dynamic conditions (translation, rotation, and expansion). Angles were parts of imaginary triangles, defined by three vertex dots. Compared to static angles, results show no significant decline in the precision of angle judgments for any of the three motion types, up to speeds high enough to impair target visibility. Additional experiments provide evidence against a uniform mechanism underlying static and dynamic performance, which could rely on "snapshots" when processing moving angles. Rather, we find support for distinct mechanisms. Firstly, adding noise dots to the display affects rotating and expanding angles substantially more than those which are translating or static. Secondly, the ability to judge angles is unaffected when vertex dots are occluded for short periods. Given the dependence of dot trajectories on the overall triangle motion, the ability to precisely extrapolate the future position of a dot requires distinct computations for translating, expanding, and rotating shapes. |
| | |
Authors:
|
Graeme J Kennedy; Harry S Orbach; Gael E Gordon; Gunter Loffler |
Related Documents
:
|
12696859 - Tilt aftereffects generated by symmetrical dot patterns with two or four axes of symmetry. 3039079 - Nonlinear directionally selective subunits in complex cells of cat striate cortex. 10683459 - The role of relative motion computation in 'direction repulsion'. 9474339 - Motion transparency in superimposed dense random-dot patterns: psychophysics and simula... 12450509 - Central and peripheral interactions in the perception of optic flow. 17753209 - Weber ratio for visual discrimination of velocity. 9178219 - Visual object localization through vestibular and neck inputs. 1: localization with res... 13891769 - Retinal receptor potentials and their linear relationship to light intensity. 10718069 - The differential effects of simultaneous and successive cueing on the detection of bila... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2008-10-29 |
Journal Detail:
|
Title: Journal of vision Volume: 8 ISSN: 1534-7362 ISO Abbreviation: J Vis Publication Date: 2008 |
Date Detail:
|
Created Date: 2009-01-16 Completed Date: 2009-04-21 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 101147197 Medline TA: J Vis Country: United States |
Other Details:
|
Languages: eng Pagination: 9.1-13 Citation Subset: IM |
Affiliation:
|
Department of Vision Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, UK. graeme.kennedy@gcal.ac.uk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Discrimination (Psychology) / physiology* Form Perception / physiology* Humans Male Motion Perception / physiology* Photic Stimulation / methods Rotation Time Factors Visual Perception / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Attentional selection and the representation of holes and objects.
Next Document: Asymmetry in the perception of motion in depth induced by moving cast shadows.