Spatial summation in the fovea: Asymmetrical effects of longer and shorter dimensions
Vision ResearchPublished 1 January 1978
James P. Thomas
Citations14
SJR quartileQ2
SJR score0.63
SNIP0.89
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TL;DR
The results suggest that detection is mediated by only those spatial frequency components which lie parallel to the long axis of the stimulus.
Abstract
Spatial summation was measured for foveally viewed rectangles superimposed on a 1000-td background. The longer and shorter dimensions of the stimuli were independently varied from 0 to 50′. Visibility increased as the longer dimension was increased up to 40 or 50′. However, changes in the shorter dimension affected visibility systematically only when the shorter dimension was less than 5′. When the stimulus was near the luminance threshold, the shorter dimension was more accurately estimated than the longer dimension. The results suggest that detection is mediated by only those spatial frequency components which lie parallel to the long axis of the stimulus.
Keywords
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