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PubMed · 4056951

Intensity-dependent spatial summation.

T N Cornsweet·J I Yellott
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Abstract

Psychophysical evidence indicates that, in the human retina, the size of the spatial-summation area decreases as illuminance increases. Such a relationship would be beneficial for the detection of spatial contrast in the presence of photon noise. We analyze an image-processing mechanism in which the area of a strictly positive point-spread function varies inversely with local illuminance while its volume remains constant. In addition to its expected effect of improving spatial resolution as illuminance increases, this mechanism also yields center-surround antagonism and all other manifestations of bandpass filtering and accounts for Ricco's law and Weber's law--including the failures of both laws as a function of test conditions. The relationship between this mechanism and lateral inhibition is analyzed.

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HumansMathematicsModels, BiologicalModels, PsychologicalPhotic StimulationRetinaSpace PerceptionJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

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T N Cornsweet, J I Yellott. 1985. Intensity-dependent spatial summation.. https://doi.org/10.1364/josaa.2.001769

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