Responses to second-order texture modulations undergo surround suppression

Vision Res. 2012 Jun 1:62:192-200. doi: 10.1016/j.visres.2012.03.008.

Abstract

First-order (contrast) surround suppression has been well characterized both psychophysically and physiologically,but relatively little is known as to whether the perception of second-order visual stimuli exhibits analogous center–surround interactions. Second-order surround suppression was characterized by requiring subjects to detect second-order modulation in stimuli presented alone or embedded in a surround.Both contrast- (CM) and orientation-modulated (OM) stimuli were used. For most subjects and both OM and CM stimuli, second-order surrounds caused thresholds to be higher, indicative of second-order suppression. For CM stimuli, suppression was orientation-specific, i.e., higher thresholds for parallel than for orthogonal surrounds. However, the evidence for orientation specificity of suppression for OM stimuli was weaker. These results suggest that normalization, leading to surround suppression, operates at multiple stages in cortical processing.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Contrast Sensitivity / physiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pattern Recognition, Visual / physiology*
  • Photic Stimulation / methods
  • Psychophysics
  • Sensory Thresholds / physiology