Over the last 20 years, visual illusions, like the Ebbinghaus figure, have become widespread to investigate functional segregation of the visual system. This segregation reveals itself, so it is claimed, in the insensitivity of movement to optical illusions. This claim, however, faces contradictory results (and interpretations) in the literature. These contradictions may be due to methodologica...

Visual distortions of perceived lengths, angles, or forms, are generally known as “geometric–optical illusions” (GOI). In the present paper we focus on a class of GOIs where the distortion of a straight line segment (the “target” stimulus) is induced by an array of non-intersecting curvilinear elements (“context” stimulus). Assuming local target– context interactions in a vector field represent...

Geometric-optical illusions (goi) are a subclass of a vast variety of visual illusions. A special class of gois originates from the superposition of a simple geometric figure (“target”) with an array of non-intersecting curvilinear elements (“context”) that elicits a perceptual distortion of the target element. Here we specifically deal with the case of circular targets. Starting from the fact ...

A new class of objects, called topology-disturbing objects, is presented. These objects appear to disturb topological properties when they are seen from two specific viewpoints; for example, two objects appear to be separated when seen from one viewpoint while they appear to be intersecting when seen from the other viewpoint. This cannot happen physically, but due to the phenomenon of an optica...