Document Detail


Is global motion really based on spatial integration of local motion signals?
MedLine Citation:
PMID:  7975281     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Previous studies have shown that a random-dot kinematogram (RDK) comprising dots, each of which takes a random walk in direction or speed over time, can appear to flow in a single direction. This has been interpreted as evidence for the existence of a co-operative network linking neurons sensitive to different directions/speeds and different spatial locations. We have investigated the possibility that global motion perception in such patterns might simply reflect motion energy detection at a coarse spatial scale (such that many dots fall in the receptive field of one energy detector) without the need to encode local dot motions on a fine spatial scale and then integrate their motions over space. We created random-walk RDKs and then spatially high-pass filtered them to remove low spatial frequencies. Perception of global motion was unimpaired for both direction and speed random walks, showing that the phenomenon is not reliant on low spatial frequencies and must, therefore, involve integration of local motion signals across space, as originally postulated.
Authors:
A T Smith; R J Snowden; A B Milne
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Vision research     Volume:  34     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  1994 Sep 
Date Detail:
Created Date:  1994-12-09     Completed Date:  1994-12-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  2425-30     Citation Subset:  IM; S    
Affiliation:
Vision Research Unit, School of Psychology, University of Wales College of Cardiff.
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MeSH Terms
Descriptor/Qualifier:
Discrimination (Psychology) / physiology
Humans
Motion Perception / physiology*
Pattern Recognition, Visual / physiology*
Psychometrics
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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