Unconscious inference
Main article: Unconscious inference
Hermann von Helmholtz is often credited with the first modern study of visual perception. Helmholtz examined the human eye and concluded that it was incapable of producing a high quality image. Insufficient information seemed to make vision impossible. He therefore concluded that vision could only be the result of some form of “unconscious inference”, coining that term in 1867. He proposed the brain was making assumptions and conclusions from incomplete data, based on previous experiences.# ISO certification in India
Inference requires prior experience of the world.
Examples of well-known assumptions, based on visual experience, are:
- light comes from above
- objects are normally not viewed from below
- faces are seen (and recognized) upright.
- closer objects can block the view of more distant objects, but not vice versa
- figures (i.e., foreground objects) tend to have convex borders
The study of visual illusions (cases when the inference process goes wrong) has yielded much insight into what sort of assumptions the visual system makes.
Another type of the unconscious inference hypothesis (based on probabilities) has recently been revived in so-called Bayesian studies of visual perception.Proponents of this approach consider that the visual system performs some form of Bayesian inference to derive a perception from sensory data. However, it is not clear how proponents of this view derive, in principle, the relevant probabilities required by the Bayesian equation. Models based on this idea have been used to describe various visual perceptual functions, such as the perception of motion, the perception of depth, and figure-ground perception.[[17] The “wholly empirical theory of perception” is a related and newer approach that rationalizes visual perception without explicitly invoking Bayesian formalisms. # ISO certification in India
Gestalt theory
Main article: Gestalt psychology
Gestalt psychologists working primarily in the 1930s and 1940s raised many of the research questions that are studied by vision scientists today.
The Gestalt Laws of Organization have guided the study of how people perceive visual components as organized patterns or wholes, instead of many different parts. “Gestalt” is a German word that partially translates to “configuration or pattern” along with “whole or emergent structure”. According to this theory, there are eight main factors that determine how the visual system automatically groups elements into patterns: Proximity, Similarity, Closure, Symmetry, Common Fate (i.e. common motion), Continuity as well as Good Gestalt (pattern that is regular, simple, and orderly) and Past Experience.# ISO certification in India