| Tuning for temporal interval in human apparent motion detection. | |
| | |
MedLine Citation:
|
PMID: 17461670 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval. |
| | |
Authors:
|
Roger J E Bours; Sanne Stuur; Martin J M Lankheet |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2007-01-08 |
Journal Detail:
|
Title: Journal of vision Volume: 7 ISSN: 1534-7362 ISO Abbreviation: J Vis Publication Date: 2007 |
Date Detail:
|
Created Date: 2007-04-27 Completed Date: 2007-05-08 Revised Date: 2008-04-29 |
Medline Journal Info:
|
Nlm Unique ID: 101147197 Medline TA: J Vis Country: United States |
Other Details:
|
Languages: eng Pagination: 2 Citation Subset: IM |
Affiliation:
|
Functional Neurobiology and Helmholtz Institute, Utrecht University, Utrecht, The Netherlands. r.j.e.bours@bio.uu.nl |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Discrimination (Psychology) Humans Models, Psychological Motion Perception / physiology* Photic Stimulation / methods Psychophysics Sensory Thresholds Time Factors Visual Perception |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The effect of viewpoint on perceived visual roughness.
Next Document: Some observations on the pedestal effect.