Filling-In and Suppression of Visual Perception from Context: A Bayesian Account of Perceptual Biases by Contextual Influences

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Filling-In and Suppression of Visual Perception from Context: A Bayesian Account of Perceptual Biases by Contextual Influences

Zhaoping, L; Jingling, L; (2008) Filling-In and Suppression of Visual Perception from Context: A Bayesian Account of Perceptual Biases by Contextual Influences. PLOS COMPUT BIOL , 4 (2) , Article e14. 10.1371/journal.pcbi.0040014. Green open access

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Abstract

Visual object recognition and sensitivity to image features are largely influenced by contextual inputs. We study influences by contextual bars on the bias to perceive or infer the presence of a target bar, rather than on the sensitivity to image features. Human observers judged from a briefly presented stimulus whether a target bar of a known orientation and shape is present at the center of a display, given a weak or missing input contrast at the target location with or without a context of other bars. Observers are more likely to perceive a target when the context has a weaker rather than stronger contrast. When the context can perceptually group well with the would-be target, weak contrast contextual bars bias the observers to perceive a target relative to the condition without contexts, as if to fill in the target. Meanwhile, high-contrast contextual bars, regardless of whether they group well with the target, bias the observers to perceive no target. A Bayesian model of visual inference is shown to account for the data well, illustrating that the context influences the perception in two ways: (1) biasing observers' prior belief that a target should be present according to visual grouping principles, and (2) biasing observers' internal model of the likely input contrasts caused by a target bar. According to this model, our data suggest that the context does not influence the perceived target contrast despite its influence on the bias to perceive the target's presence, thereby suggesting that cortical areas beyond the primary visual cortex are responsible for the visual inferences.

Type:	Article
Title:	Filling-In and Suppression of Visual Perception from Context: A Bayesian Account of Perceptual Biases by Contextual Influences
Open access status:	An open access version is available from UCL Discovery
DOI:	10.1371/journal.pcbi.0040014
Publisher version:	http://dx.doi.org/10.1371/journal.pcbi.0040014
Language:	English
Additional information:	© 2008 Zhaoping and Jingling. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keywords:	DETECTION FACILITATION, MASKING EXPERIMENTS, CONTRAST DETECTION, COLLINEAR STIMULI, SCENE PERCEPTION, BORDER OWNERSHIP, COLOR CONSTANCY, STRIATE CORTEX, RESPONSES, MONKEY
UCL classification:	UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
URI:	https://discovery.ucl.ac.uk/id/eprint/5256