Search results
Results from the WOW.Com Content Network
The MIT Encyclopedia of the Cognitive Sciences explains the illusion as an effect of "size and shape constancy [which] subjectively expand[s] the near-far dimension along the line of sight." [4] It classifies Shepard tables as an example of a geometrical illusion, in the category of an "illusion of size." [4]
Subjective constancy or perceptual constancy is the perception of an object or quality as constant even though our sensation of the object changes. [1] While the physical characteristics of an object may not change, in an attempt to deal with the external world, the human perceptual system has mechanisms that adjust to the stimulus.
Example problem based on Shepard & Metzlar's "Mental Rotation Task": are these two three-dimensional shapes identical when rotated? Mental rotation is the ability to rotate mental representations of two-dimensional and three-dimensional objects as it is related to the visual representation of such rotation within the human mind. [1]
Movement also helps; the figure may be moving against a static environment. Color is also a cue because the background tends to continue as one color behind potentially multiple foreground figures, whose colors may vary. Edge assignment also helps; if the edge belongs to the figure, it defines the shape while the background exists behind the shape.
Form perception is the recognition of visual elements of objects, specifically those to do with shapes, patterns and previously identified important characteristics. An object is perceived by the retina as a two-dimensional image, [1] but the image can vary for the same object in terms of the context with which it is viewed, the apparent size of the object, the angle from which it is viewed ...
It contradicts the Ebbinghaus illusion (1898) and the Obonai square illusion (1954). In fact, the central test shape (a cross) surrounded by large squares appears larger instead of smaller. Sarcone's Cross illusion consists of a cross (the test shape) surrounded by sets of squares of distinct size (the inducing shapes).
Marr's 2 1 ⁄ 2 D sketch assumes that a depth map is constructed, and that this map is the basis of 3D shape perception. However, both stereoscopic and pictorial perception, as well as monocular viewing, make clear that the perception of 3D shape precedes, and does not rely on, the perception of the depth of points.
Visual object recognition refers to the ability to identify the objects in view based on visual input. One important signature of visual object recognition is "object invariance", or the ability to identify objects across changes in the detailed context in which objects are viewed, including changes in illumination, object pose, and background context.