Lecture 8: Perceptual Organization i. ii. iii. iv. v. vi. Perceptual Illusions a. To understand how perception is organized, illusions provide good examples Figure and Ground a. Our brain must decide what is figure and ground b. Then it has to decide which part of an object goes with which part Depth Perception a. Depth perception enables us to judge distances b. 2 types of cues i. Binocular ii. Monocular Binocular Cues a. Retinal disparity (binocular disparity) i. Our eyes are located slightly apart ii. Image on each retina is slightly different iii. When brain combines images, see things in 3-d iv. This is how 3-d movies and tv works b. Convergence i. Our eyes move together to focus on something close, farther apart for distant objects Perceptual Constancies a. Perceiving the properties of an object to remain the same even though the physical properties are changing i. Retinal image changes but our percept stays the same b. Shape constancy i. Shape perception same, retinal image different c. Size constancy i. We perceive an object as same size, even if retinal size changes d. Color constancy i. Color of an object remains the same under different illuminations 1. However, when context changes, color of an object may look different All the time? a. Perceptual constancies i. Retinal image changes, percept stays the same b. Checkerboard illusion i. Retinal image same- percept changes ii. Depends on context iii. CHANGE CONTEXT, PERCEPT CHANGES