Download Perception and Recognition of Objects: A Gestalt Approach and more Assignments Cognitive Psychology in PDF only on Docsity! 4 Perceiving and Recognizing Objects 4 Pandemonium • Oliver Selfridge (1959) • Simple model of letter recognition • “Demons” loosely represent neurons; each level represents a different brain area • “Perception by committee” • Pandemonium Model Online 4 Object Ambiguity 4 More Ambiguity: Accidental Views 4 More Ambiguity: Accidental Views (cont’d) Finding Edges (cont'd)
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SENSATION AND PERCEPTION, Figure 4.5 © 2006 Sinauer Associates, Inc.
4 Gestalt Grouping “Laws” • Pragnanz - Simplicity • Similarity • Good Continuation • Proximity • Connectedness • Common Fate • Familiarity 4 Good Continuation (a) ——
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FLEGURE 6 18 Twocxamples of the law of
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FIGURE 6. 25 Symmetry and figure-
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4 Problems with the Gestalt Approach
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4 Rules for Linking Contours • Good continuation: group elements to form smoothly continuing lines 4 Gestalt Psychology • “The whole is greater than the sum of its parts” • Wertheimer, Köhler, Koffka (1920s–1950s); Palmer and Rock (1990s) • Reaction to earlier structuralist school of psychology 4 Parallelism/Symmetry • Somewhat weaker grouping principles—group parallel and symmetric elements together 4 Dynamic Grouping Principles • Common fate: group elements moving in the same direction together 4 Dynamic Grouping Principles (cont’d) 4 Modern Gestaltism • Common region: Elements perceived to be part of a larger region group together • Connectedness: Elements that are connected to each other group together 4 Figure–Ground Segmentation • What is the to-be-recognized object and what is the background? – Gestalt figure–ground assignment principles: surroundedness, size, symmetry, parallelism 4 Meaning and Figure–Ground Assignment • Is brown or white the figure here? • Object recognition starts before figure–ground assignment finishes Problems with the Gestalt Approach
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Problems with the Gestalt Approach
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4 Meaning in the Edges • Non-accidental features provide clues to object structure 4 Figure 5.35, page 165 Visual search stimuli C o p y ri g h t © 2 0 0 2 W a d s w o rt h G ro u p . W a d s w o rt h i s a n i m p ri n t o f th e W a d s w o rt h G ro u p , a d iv is io n o f T h o m s o n L e a rn in g
The Relatability Principle (cont’d)
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SENSATION AND PERCEPTION, Figure 4.21 © 2006 Sinauer Associates, Inc.
SENSATION AND PERCEPTION, Figure 4.25 © 2006 Sinauer Associates, Inc.
4 4.33 Cells in the inferotemporal cortex of macaque monkeys are interested in very specific stimuli SENSATION AND PERCEPTION, Figure 4.31 © 2006 Sinauer Associates, Inc.
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