Polarity-dependent orientation illusions: Review, model, and simulations. (December 2021)

• Record Type: Journal Article
• Authors: Todorović, Dejan
• Is Part Of: Vision research. Volume 189(2021)
• Page Start: 54
• Page End: 80
• Publication Date: 2021-12
• Subjects: Orientation illusions -- Café wall illusion -- Computational model -- Simple cells simulation; Vision -- Periodicals; 573.88
• DOI: 10.1016/j.visres.2021.09.003
• Languages: English
• ISSNs: 0042-6989

Abstract

Graphical abstract: Highlights: Many examples of a special class of orientation illusions are presented. A neurocomputational model of this class of illusions is introduced. Simulations of the model indicate a signature feature of illusion-inducing displays. The neural bases of tilt impressions are population activation patterns. Abstract: Polarity-dependent orientation illusions are manifested in figures in which the impression of target orientation does not depend only on geometrical relations between the elements of the figure, but also on the relations between their luminances, that is, on luminance polarities. The best-known phenomenon belonging to this class of effects is the Münsterberg/Café Wall illusion. In this paper a considerable number of examples of this type of illusions are presented, many of which are novel variants. A two-level convolutional model of such illusions is introduced, in which the first level corresponds to the stimulus input and the second level contains units fashioned after simple cells in V1, whose spatial patterns of activity represent the model's reaction to the stimulus. The main finding of numerous simulations of the model is that the figures inducing illusory impressions of tilt share a common spatial pattern of neural activation, labeled 'oblique clusters', which is absent in related non-illusory figures. Furthermore, a similar pattern is also present in simulations of figures which induce veridical impressions of tilt. The simulations suggest that the neural basis of perception of a specific degree of tilt may not be the activity of neurons tuned narrowly to that particular degree of tilt, but rather the presence of certain signature spatial patterns of activity of populations of neurons.