Notetaker: Victor Law
Advanced Placement Psychology
Chapter 6: Perception
(
http://www.ApPsychology.net )
Selective Attention
• Selective attention: focusing only on one thing at a time; focused awareness only on limited aspect of all that is
capable of experiencing; you aren’t aware of nose in line of vision
• Cocktail Party Effect: (example of selective attention) ability to focus only on one voice in a huge crowd
• Unnoticed stimuli has effect: women who had listened to tunes previously played to them while unnoticed preferred it
later on
Perceptual Illusions
• Visual capture: phenomenon when a conflict occurs between vision and another sense, vision dominates; vision
captures other senses (overrides)
• in theaters, sound comes from behind (projector), yet perceive as from screen
• Perceiving voice coming from ventriloquist’s dummy
Perceptual Organization
• Humans organize clusters of sensation into gestalt: organized “whole”; human tendency to order pieces of info into a
meaning picture
• First perceptual task: to perceive figure (object) as distinct from ground (background)
• Figure-ground: organization of visual field into the figure(s) that stand out from the ground
• Next, organize figure into meaningful form (color, movement, like-dark contrast)
• To process forms, use grouping: rules mind follows to organize stimuli into logical groups
• Grouped into Proximity, Similarity, Continuity, Closure, Connectedness (visuals on page 185, figure 6.5 and
definition on page 186 of 5 edition)
• Depth perception: ability to see objects in 3D even though image sensed by retina are 2D; allows distance judgment;
partly innate (born with)
• Gibson and Walker placed 6-14 months old infants on edge of a visual cliff (table half glass, half wood), making the
appearance of a drop-off; Mothers then tries to convince infant to crawl pass the normal part of the table onto glass;
most refused, indicating perception of depth
• Visual cliff: laboratory device for testing depth perception in infants/animals
• Binocular cues: depth cues that depend on both eyes
• Eyes apart, slightly different images, brain sees difference –retinal disparity: bi cue in which the greater the
difference between images, the closer the object
• Convergence: bi cue in which the more the eyes turns inward, the closer the object
• Monocular cues: distance cue that are available to either eye
• Examples: relative size, interposition, relative clarity, texture gradient, relative height, relative motion, linear
perspective, relative brightness (definitions on pages 188-189 of 5 edition)
• Brain computes motion base partly on assumption that objects moving away is shrinking & vise versa
• Brain reads rapid series of slightly different images as movement; phenomenon called stroboscopic movement
• Another illusion of movement is phi phenomenon: perception of movement when lights blink one after the other; the
lighted arrow signs on the back of parked constructi on trucks
• Perceptual constancy: perception that objects are not changing even under different lighting; allowing identification
regardless of angle of view [a door is a door even at 45 degree (shape constancy) angle or 20 feet away(size
constancy)]
• Even at same size, linear perspective causes one to see one object bigger (page 191 figure 6.13a)
