It seems that the grand illusion is the result of a considerable amount of top-down interpretation of very fragmentary visual information. Important changes that might occur while driving, for example, create motion signals that draw our attention so that we become aware of them. B) Feature Integration Theory Introduced by Anne Treisman, the feature integration theory states(FIT) : before we can attend to objects in the world we must extract the features that make up these objects The theory is based on the assumption that when we initially view objects in our field of vision we first extract and represent their features (colour, orientation) across the entire visual field through a process called pre-attentive processing . FIT assumes that for an object to be perceived as a whole object, there has to be feature binding at specific locations. Feature binding is a accomplished by a stage of processing known as attentive processing. Feature binding: the combination of visual features by attention to form whole objects
C OGNITION - L ECTURE THREE : P ERCEPTION 1/14/2010 Attentive processing: combining features into a whole object through attention. If a feature pops out of a display, then that feature, a pop-out , is a good candidate for being a basic property out of which we construct perceived objects. C) The Constraints of the Visual System Blind spot : A region in the eye where the optic nerve leaves the retina; it does not contain any photoreceptors. Perceptual completion (filling-in): The experience that something is present in part of a visual scene when actually it is absent from that spot, but is present in the surrounding region. Perceiving Whole Objects: Gestalt psychology Gestalt psychology (koffka, Kohler): A branch of psychology that focuses on dealing with wholes rather than parts. One of the main demonstrations forwarded by the Gestalters was that a resulting percept is not simply a straightforward function of the elements in a visual field. Ex. Through bi-stable figures Bi-stable figures: Images from which two separate percept can be formed. Gaetano Kanizsa defined the word gestalt as follows: ‘Gestalt’ ought to be translated as ‘organized structure’, as distinguished from ‘aggregate’, ‘heap’, or simply ‘summation’. When it is appropriately translated, the accent is on the concept of ‘organization’ and of a ‘whole’ that is orderly, rule-governed, non-random. Believed that perception is holistic (focusing on the whole configuration of an object) in nature rather than atomistic (focusing on the features or components of objects). Also, that there are fundamental organizational principles by which we group visual elements in order to perceive a whole. Organizational principles : the rules that explain the ways in which people are able to perceive whole objects or events from individual parts.
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- Winter '08
- COGNITION- LECTURE