Collinear interactions and contour integration

U. Polat, Y. Bonneh

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


The visibility of a local target is influenced by the global configuration of the stimulus. Collinear configurations are a specific case in which facilitation or suppression of the target has been found to be dependent on the contrast threshold of the target. The role of collinear interactions in perceptual grouping, especially in contour integration, is still controversial. In the current study, the role of collinear interactions in noise was investigated using experimental conditions similar to those utilized in studies of contour integration. The contrast detection paradigm in the presence of similar Gabor elements presented in the background was used. The results show that contrast detection threshold of the target alone is increased (suppression) when it is embedded in randomly oriented background elements. However, when the target is flanked by two collinear Gabor elements, the target is facilitated even at higher target contrast levels. Facilitation is not found for orthogonal configurations. The results suggest that the response to a local element in a contour is modified by lateral facilitative and suppressive inputs from elements comprising the smooth contour and randomly oriented background elements, respectively. Thus, detection of elements along a contour should be considered as integration of global neuronal activity rather than as the output of local and individual neurons.

Original languageEnglish
Pages (from-to)393-401
Number of pages9
JournalSpatial Vision
Issue number4
StatePublished - 2000
Externally publishedYes


  • Context
  • Contour integration
  • Contrast
  • Facilitation
  • Long-range interactions
  • Perceptual grouping
  • Suppression
  • Threshold


Dive into the research topics of 'Collinear interactions and contour integration'. Together they form a unique fingerprint.

Cite this