Skip to main content

Research Repository

Advanced Search

Strong perceptual consequences of low-level visual predictions: A new illusion

Jovanovic, Ljubica; Trichanh, Mélanie; Martin, Brice; Giersch, Anne

Strong perceptual consequences of low-level visual predictions: A new illusion Thumbnail


Ljubica Jovanovic

Mélanie Trichanh

Brice Martin

Anne Giersch


Predicting information is considered to be an efficient strategy to minimise processing costs by exploiting regularities in the environment, and to allow for adaptation in case of irregularities, i.e. prediction errors. How such errors impact conscious perception is unclear, especially when predictions concern elementary visual features. Here we present results from a novel experimental approach allowing us to investigate the perceptual consequences of violated low-level predictions about moving objects. Observers were presented with two squares moving towards each other with a constant speed, and reported whether they were in contact or not before they disappeared. A compelling illusion of a gap between the squares occurred when the leading edges of those squares contacted briefly. The apparent gap was larger than a physical and stable separation of 2.6 min of arc between the squares. The illusion disappeared only when the contact did not violate extrapolations of the contrast edge between the moving object and the background. The pattern of results is consistent with an early locus of the effect and cannot be explained by decisional biases, guesses, top-down, attentional or masking effects. We suggest that violations of the contrast edge extrapolation in the direction of motion have strong perceptual consequences.


Jovanovic, L., Trichanh, M., Martin, B., & Giersch, A. (2023). Strong perceptual consequences of low-level visual predictions: A new illusion. Cognition, 230, Article 105279.

Journal Article Type Article
Acceptance Date Aug 30, 2022
Online Publication Date Sep 12, 2022
Publication Date Jan 1, 2023
Deposit Date Oct 27, 2022
Publicly Available Date Oct 27, 2022
Journal Cognition
Print ISSN 0010-0277
Electronic ISSN 1873-7838
Publisher Elsevier BV
Peer Reviewed Peer Reviewed
Volume 230
Article Number 105279
Keywords Cognitive Neuroscience; Linguistics and Language; Developmental and Educational Psychology; Language and Linguistics; Experimental and Cognitive Psychology
Public URL
Publisher URL


Downloadable Citations