| The role of relative motion computation in 'direction repulsion'. | |
| | |
MedLine Citation:
|
PMID: 10683459 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
When two sets of intermixed dots move in different directions the perceived direction of each is considerably shifted [Marshak & Sekuler (1979). Science, 205, 1399-1401; Mather & Moulden, (1980). Quarterly Journal of Experimental Psychology, 32, 325-333)]. This phenomenon has been attributed to 'repulsive' interactions between channels tuned to different directions of motion. However, we report that it is not only the relative direction, but also the density and speed of the sets, which determines the magnitude of the apparent shift. These results are difficult to reconcile with the notion of 'repulsive' interactions, and we describe an alternative, functionally motivated explanation. In the natural environment, observed motion results from objects moving over background surfaces that may themselves be mobile. Disentanglement of motion signals therefore necessitates a computation of relative motion. We propose that the phenomenon of 'direction repulsion' results from a deliberate adjustment of observed motion to compensate for an inferred source of 'background' motion. A simple scheme to do this subtracts the weighted vector-sum of all motion signals from observed motion. This relative motion computation quantitatively predicts the observed effects of the density of dot sets on perceived direction. The effects of speed cannot be reconciled with the scheme as it stands, but this could be due to the model's failure to consider the effect of temporal frequency on the effective contrast of the sets. |
| | |
Authors:
|
S C Dakin; I Mareschal |
Related Documents
:
|
4071989 - Effects of spatial separation and retinal eccentricity on two-dot vernier acuity. 1542059 - Model for the computation of self-motion in biological systems. 15838949 - The relative role of visual and non-visual cues in determining the perceived direction ... 2487639 - Human horizontal optokinetic nystagmus elicited by the upper versus the lower visual fi... 2321359 - New phenomena linking depth and luminance in stereoscopic motion. 19479619 - The effect of abdominal kinematic directives on respiratory behaviour in female classic... 1525539 - Some unresolved issues in the physiology and biochemistry of phototransduction. 10646289 - The effect of nerve cuff geometry on interference reduction: a study by computer modeling. 20600739 - Polarity effects on neural responses of the electrically stimulated auditory nerve at d... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Vision research Volume: 40 ISSN: 0042-6989 ISO Abbreviation: Vision Res. Publication Date: 2000 |
Date Detail:
|
Created Date: 2000-07-20 Completed Date: 2000-07-20 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0417402 Medline TA: Vision Res Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 833-41 Citation Subset: IM; S |
Affiliation:
|
Department of Visual Science, Institute of Ophthalmology, 11-43 Bath Street, London, UK. s.dakin@ucl.ac.uk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Female Humans Male Models, Psychological Motion Perception / physiology* Optical Illusions / physiology* Photic Stimulation / methods Psychophysics |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Chromatic and luminance contributions to a hyperacuity task.
Next Document: Image formation by bifocal lenses in a trilobite eye?