| Speed tuning of motion segmentation and discrimination. | |
| | |
MedLine Citation:
|
PMID: 10789424 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Motion transparency requires that the visual system distinguish different motion vectors and selectively integrate similar motion vectors over space into the perception of multiple surfaces moving through or over each other. Using large-field (7 degrees x 7 degrees) displays containing two populations of random-dots moving in the same (horizontal) direction but at different speeds, we examined speed-based segmentation by measuring the speed difference above which observers can perceive two moving surfaces. We systematically investigated this 'speed-segmentation' threshold as a function of speed and stimulus duration, and found that it increases sharply for speeds above approximately 8 degrees/s. In addition, speed-segmentation thresholds decrease with stimulus duration out to approximately 200 ms. In contrast, under matched conditions, speed-discrimination thresholds stay low at least out to 16 degrees/s and decrease with increasing stimulus duration at a faster rate than for speed segmentation. Thus, motion segmentation and motion discrimination exhibit different speed selectivity and different temporal integration characteristics. Results are discussed in terms of the speed preferences of different neuronal populations within the primate visual cortex. |
| | |
Authors:
|
G S Masson; D R Mestre; L S Stone |
Related Documents
:
|
487064 - Seaward orientation of hatchling turtles: turning systems in the optic tectum. 3373454 - Deep tectal cells in pigeons respond to kinematograms. 1528704 - Reduced spatial sensitization on nonuniform backgrounds. 11396394 - The effect of perceived length on visuomotor localization. 16657074 - Level of photosynthetic intermediates in isolated spinach chloroplasts. 9603624 - Double resonance experiments in a single resonance probe: detecting 23na-51v dipolar in... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: Vision research Volume: 39 ISSN: 0042-6989 ISO Abbreviation: Vision Res. Publication Date: 1999 Oct |
Date Detail:
|
Created Date: 2000-05-22 Completed Date: 2000-05-22 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0417402 Medline TA: Vision Res Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 4297-308 Citation Subset: IM; S |
Affiliation:
|
Centre de Recherche en Neurosciences Cognitives, Marseille, France. masson@lnf.cnrs-mrs.fr |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Discrimination (Psychology)
/
physiology* Humans Motion Perception / physiology* Photic Stimulation Sensory Thresholds / physiology* Vision, Binocular Visual Perception / physiology* |
| Investigator | |
Investigator/Affiliation:
|
L S Stone / ARC |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Bilateral basal-cell adenomas in the parotid glands.
Next Document: A new approach to the study of ocular chromatic aberrations.