Center-surround interactions in foveal and peripheral vision.
The perceived contrast of a central stimulus can be decreased (surround suppression) or increased (surround facilitation) by the presence of surround stimuli. In this report we examined center-surround interactions in foveal and peripheral vision using contrast-matching tasks. We found that: (1) surround suppression became markedly stronger as the center-surround stimulus was moved toward the periphery; (2) surround facilitation diminished in the periphery; and (3) the suppression in the periphery was less orientation- and frequency-specific than that in the fovea, so that significant suppression was induced even when the central and surround gratings had very different orientations and spatial frequencies. The different center-surround interactions in the fovea and periphery can not be accounted for by cortical magnification, suggesting that center-surround interactions in the fovea and periphery are incommensurable and play different functional roles in human image processing.
Xing
J
J
Department of Psychology, Jordan Hall, Bldg. 420, Stanford University, 94305-2130, Stanford, CA, USA.
Heeger
D J
DJ
D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D010470:Perceptual Masking / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*