Document Detail


A reduction in the number of directionally selective neurons extends the spatial limit for global motion perception.
MedLine Citation:
PMID:  7863612     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Dynamic random-dot targets were used to study neural mechanisms underlying motion perception. Performance of cats with severely reduced numbers of cortical directionally selective neurons (reduced DS) was compared to that of normal animals. We assessed the spatial properties of the residual motion mechanism by measuring direction discriminations at various dot displacements. At small displacements, reduced DS cats' motion integration thresholds for opposite direction discrimination were nearly normal. At larger displacements, their thresholds surpassed those of normal cats and their upper displacement limit (dmax) was increased by 0.35 deg. The accuracy of direction discrimination was reduced at small displacements, but at larger displacements direction difference thresholds of reduced DS cats approached or surpassed those of normals. These data were compared to the performance of humans who showed an extension of dmax for peripherally viewed targets. The data support the hypothesis that expansion in spatial scale of the motion mechanism may contribute to extension of dmax. Additional support for this hypothesis is provided by a modified direction discriminating line-element model. The model also suggests that changes in sampling of motion mechanisms in the reduced DS system may play a role.
Authors:
K K Rudolph; V P Ferrera; T Pasternak
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Vision research     Volume:  34     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  1994 Dec 
Date Detail:
Created Date:  1995-03-17     Completed Date:  1995-03-17     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  3241-51     Citation Subset:  IM; S    
Affiliation:
Department of Psychology, University of Rochester, NY 14627-0270.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Cats
Discrimination (Psychology) / physiology
Humans
Mathematics
Models, Biological
Motion Perception / physiology*
Pattern Recognition, Visual / physiology*
Psychophysics
Sensory Deprivation / physiology
Sensory Thresholds / physiology
Time Factors
Visual Cortex / physiology*
Visual Fields
Grant Support
ID/Acronym/Agency:
EY01319/EY/NEI NIH HHS; EY06175/EY/NEI NIH HHS

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


Previous Document:  Reflections on the pathogenesis of diseases caused by the acute avian leukosis/sarcoma viruses with ...
Next Document:  Illusory perception of gratings stimulating a small number of neurones.