Document Detail


The role of contrast sensitivity in global motion processing deficits in the elderly.
MedLine Citation:
PMID:  20884480     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
This study compared the effects of age on the perception of translational, radial, and rotational global motion patterns. Motion coherence thresholds were measured for judging the direction of each motion type as a function of contrast (visibility) and temporal sampling rate in young and elderly participants. Coherence thresholds decreased as dot contrast increased asymptoting at high dot contrasts but were higher in elderly compared to young participants. This equated to global motion impairment in the elderly of a factor of around 2, characterized by a shift of the threshold vs. contrast function along the horizontal axes (dot contrast). The effect of contrast interacted with the temporal sampling rate. Old participants were deleteriously affected by reduced temporal sampling particularly at low contrasts. The findings suggest that age-related changes in global motion perception may be driven principally by deficits in contrast encoding, rather than by deficits in motion integration and suggest a role for increased internal noise in the older visual system.
Authors:
Harriet A Allen; Claire V Hutchinson; Tim Ledgeway; Precius Gayle
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-08-17
Journal Detail:
Title:  Journal of vision     Volume:  10     ISSN:  1534-7362     ISO Abbreviation:  J Vis     Publication Date:  2010  
Date Detail:
Created Date:  2010-10-04     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101147197     Medline TA:  J Vis     Country:  United States    
Other Details:
Languages:  eng     Pagination:  15     Citation Subset:  IM    
Affiliation:
School of Psychology, University of Birmingham, Edgbaston, Birmingham, UK. h.a.allen@bham.ac.uk
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