Document Detail


Rod and cone contrast gains derived from reaction time distribution modeling.
MedLine Citation:
PMID:  20462312     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Contrast gain reflects the rapidity of response amplitude increase with increase in stimulus contrast. In physiology, contrast gain can be measured directly as the initial slope of cell contrast response function. In psychophysics, contrast gain estimation is not straightforward. Further, rod and cone contrast gains have not been measured psychophysically at mesopic light levels where both rods and cones are active, due to the difficulty in producing stimuli that excite rods and cones separately at the same adaptation level. Here, we estimated rod and contrast gains by fitting reaction time distributions measured at a light level in which rods alone (scotopic), rods and cones (mesopic), or cones alone (photopic) mediate vision. The reaction time distributions were modeled by two different strategies, a simplified diffusion model that assumes a stochastic accumulation process and a model we developed that begins with sensory input based on early visual processing impulse response functions and assumes the reaction time variability originates in the response criterion. Estimates of contrast gain from both models were comparable and consistent with primate physiology measurements.
Authors:
Dingcai Cao; Joel Pokorny
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-02-12
Journal Detail:
Title:  Journal of vision     Volume:  10     ISSN:  1534-7362     ISO Abbreviation:  J Vis     Publication Date:  2010  
Date Detail:
Created Date:  2010-05-13     Completed Date:  2010-08-13     Revised Date:  2011-10-17    
Medline Journal Info:
Nlm Unique ID:  101147197     Medline TA:  J Vis     Country:  United States    
Other Details:
Languages:  eng     Pagination:  11.1-15     Citation Subset:  IM    
Affiliation:
Department of Surgery, Section of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL, USA. d-cao@uchicago.edu
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Ocular / physiology
Animals
Color Vision / physiology
Contrast Sensitivity / physiology*
Dark Adaptation / physiology
Models, Neurological*
Photic Stimulation / methods
Primates
Psychophysics
Reaction Time / physiology
Retinal Cone Photoreceptor Cells / physiology*
Retinal Rod Photoreceptor Cells / physiology*
Sensory Thresholds / physiology
Grant Support
ID/Acronym/Agency:
EY00901/EY/NEI NIH HHS

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


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