Perception

Perception The process of selecting, organizing, and interpreting sensory information, which enables us to recognize meaningful objects and events.

Selective Attention Perceptions about objects change from moment to moment. We can perceive different forms of the Necker cube; however, we can only pay attention to one aspect of the object at a time. OBJECTIVE 1| Describe the interplay between attention and perception. Necker Cube

Inattentional Blindness

Inattentional Blindness Inattentional blindness refers to the inability to see an object or a person in our midst. Simmons & Chabris (1999) showed that half of the observers failed to see the gorilla-suited assistant in a ball passing game. Daniel Simons, University of Illinois

Change Blindness Change Blindness 2 Change Blindness 3 Color Change Card Trick

Change Blindness Change blindness is a form of inattentional blindness in which two-thirds of individuals giving directions failed to notice a change in the individual asking for directions. © 1998 Psychonomic Society Inc. Image provided courtesy of Daniel J. Simmons.

Perceptual Organization When vision competes with our other senses, vision usually wins – a phenomena called visual capture. How do we form meaningful perceptions from sensory information? We organize it. Gestalt psychologists showed that a figure formed a “whole” different than its surroundings. OBJECTIVE 3| Describe Gestalt psychology's contribution to our understanding of perception.

Gestalt Principles Proximity: when we see a number of similar objects, we tend to perceive them as groups or sets Similarity: When similar and dissimilar objects are mingled, we see the similar objects as groups

Gestalt Principles Continuity: we tend to see continuous patterns, not disrupted ones Simplicity: We see the simplest shapes possible Closure: when we see a familiar pattern or shape with some missing parts, we fill in the gaps

Form (Figure-GRound) Perception Organization of the visual field into objects (figures) that stand out from their surroundings (ground). OBJECTIVE 4| Explain the figure-ground relationship and identify principles of perceptual grouping in form perception. Time Savings Suggestion, © 2003 Roger Sheperd.

Figure-Ground Perception Figure-Ground perception is important to hearing as well as vision. Example: Listening to one voice in a noisy, crowded room.

Color Blindness Genetic disorder in which people are blind to green or red colors. This supports the Trichromatic theory. Ishihara Test

Visual Information Processing Opponent-Process Theory- opposing retinal processes enable color vision “ON” “OFF” red green green red blue yellow yellow blue black white white black

Opponent Colors Gaze at the middle of the flag for about 30 seconds. When it disappears, stare at the dot and report whether or not you see Britain's flag.