Perception and awareness of our surroundings are things we continually take for granted and without these abilities it would be impossible to navigate our way safely round our environment. Roth (1986) described perception as, "The means by which information acquired `via the sense organs is transformed into experiences of objects, events etc" This raises the question of how the sensory stimulation detected by our sense receptors is converted into conscious perceptual experience? Many theories of perception suggest that while the sensory pattern is dependent on the stimulus, it is often supplemented by other sources of information such as our knowledge and previous experience of the world and that inferences are made about the real world based on this information. This seemingly simple and effortless process has actually proved to be much more complex than first thought.
[...] This introduced the idea that perception was not a passive process but required intelligent problem solving based on knowledge. Although Helmholtz did not fully develop this idea of unconscious inferences it was extremely influential and gave subsequent theorists a concept by which to explain the processes at work in perception. A modern and more detailed version of the constructivist approach is provided by Gregory (1973, 1978) who explained perception in terms of hypotheses forming and testing, predicting unsensed characteristics of objects. [...]
[...] Present evidence suggests that perception is not based solely on unconscious inferences. The stimulus may have been underestimated in the amount of information that it contains and the influence it has directly on perception. However, unconscious inferences so far seem to be an integral part of the process of perception. Bibliography Ames, A. (1949) The Nature and Origins of Perceptions. In I.E. Gordon, Theories of Visual Perception, 161-162. Chichester: John Wiley & Sons. Bruce, V. and Green, P.R. (1990) Visual Perception. [...]
[...] (2002) Effects of occlusion on pigeons' visual object recognition. Perception, 31(11), 1299-1312. Fodor, J.A. and Pylyshyn, Z.W. (1981) How direct is visual Perception? Some reflections on Gibson's ‘ecological approach'. Cognition 139-196. Gerbino, W., and Salmaso, D. (1987) The effect of amodal completion on visual matching. Acta Psychologia 25-46. Gibson, J.J. (1979) The Ecological Approach to Visual Perception. Boston: Houghton Mifflin. Gibson, J.J. (1982) The concept of affordances in development: the renascence of functionalism. In W.A. Collins, The Concept of Development. [...]
[...] (1973) The confounded eye. In R.L. Gregory and E.H. Gombrich, Illusion in Nature and Art, 49-95. London: Duckworth. Gregory, R.L. (1978) Eye and Brain (3rd ed.). New York: McGraw-Hill. Helmholtz, H.v. (1896) Treatise on Physiological Optics, Vol. III. New York: Dover (Translation published 1962) Ittleson, W.H. (1951) Size as a cue to distance: Static localization. American Journal of Psychology 54-67. Marr, D. (1982) Vision: A Computational Investigation into the Human Representation and Processing of Visual Information. San Francisco: W.H. Freeman. [...]
[...] There seems to be little room for possibilities of explanations for this illusion that do not involve making inferences based on expectations stored in memory .Such demonstrations make it clear that perception is not perfect, as suggested by Gibson's theory, which claims that there is no difference between sensation and perception. Processes involved in identifying invariants, discovering affordances and resonance are much more complicated than implied by Gibson. When workers in the field of artificial intelligence attempted to create a model that could extract invariants from the stimuli it proved a very difficult task which led them to believe that Gibson greatly underestimated the difficulty of the detection of physical invariants (e.g. [...]
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