PERCEPTION IS…

• The process of recognizing, organizing, and interpreting sensory information

TWO THEORIES

• Bottom-up theories• -Parts are identified, put together, and then recognition

occurs

• Top-down theories• -People actively construct perceptions using information

based on expectations

CONSTANCY

• Our ability to recognize that size, shape and brightness (color) don’t change even when sensory input of an object changes.

• Size constancy• Shape constancy • Brightness constancy

SENSORY ADAPTATION

-Occurs when sensory receptors change their sensitivity to the stimulus

-Constant stimulation leads to lower sensitivity

-The brain is constantly processing and adjusting it’s perception of sensory input

SENSORY ADAPTATION CAN LEAD TO AFTER IMAGES

AFTER IMAGES IN COLOR

http://www.youtube.com/watch?v=cGt3LRZxjAw

M ODULE 07 : PERCEPTION

GESTALT ORGANIZATIONAL PRINCIPLES

GESTALT

• The “whole,” or the organizational patterns that we tend to perceive;

• the Gestalt psychologists emphasized that the whole is greater than the sum of its parts.

• By breaking experiences into their basic parts, something important is lost.

DRAW WHAT YOU JUST SAW

• Now compare your drawing with the original. • In what ways is it similar, what details did you

miss?

LAW OF PRAGANZ

• Reality is organized and reduced to the simplest form possible.

M ODULE 07 : PERCEPTION

GESTALT ORGANIZATIONAL PRINCIPLES:

FIGURE-GROUND RELATIONSHIPS

FIGURE-GROUND

• The organization of the visual field into objects (figures) that stand out from their surroundings (ground).

• The figure is the object(s) that stands out or draws one’s attention.

• The ground is the background.

FIGURE-GROUND

M ODULE 07 : PERCEPTION

GESTALT ORGANIZATIONAL PRINCIPLES:

GROUPING PRINCIPLES

GROUPING

• The perceptual tendency to organize stimuli into understandable units.

• Several principles of grouping include:• Similarity• Proximity• Closure• Continuity

GROUPING - SIMILARITY

• The tendency to place items that look similar into a group

GROUPING - PROXIMITY

• The tendency to place objects that are physically close to each other in a group

GROUPING – CLOSURE

• The tendency to look at the whole by filling in gaps in a perceptual field

http://www.youtube.com/watch?v=Hodp2esSV9E

GROUPING – CONTINUITY

• The tendency to perceive that movement of an object continues once it appears to move in a particular direction

GROUPING- COMMON FATE

• Objects that move or function in a similar manner will be seen as a unit.

WHAT PRINCIPLES DO WE SEE

DEPTH CUES

DEPTH CUES

• Eleanor Gibson and her Visual Cliff Experiment.

• If you are old enough to crawl, you are old enough to see depth perception.

• We see depth by using two cues that researchers have put in two categories:

• Monocular Cues• Binocular Cues

BINOCULAR CUES

• We need both of our eyes to use these cues.

• Retinal Disparity (as an object comes closer to us, the differences in images between our eyes becomes greater.

• Convergence (as an object comes closer our eyes have to come together to keep focused on the object).

MONOCULAR CUES

• You really only need one eye to use these (used in art classes to show depth).

• Linear Perspective• Interposition• Relative size• Texture gradient• Shadowing• Relative Height

ILLUSIONS AND PERCEPTUAL SET

PONZO ILLUSION

• Tricks our sense of size constancy

MUELLER LYON ILLUSION

• Tricks our sense of linear perspective

LETS TEST OURSELVES

• http://bcs.worthpublishers.com/gray/content/psychsim5/Visual%20Illusions/PsychSim_Shell.html

WHAT DEPTH CUES DID THE VERTICAL/HORIZONTAL LINES TRICK?

ILLUSIONS OF MOTION

• Autokinetic effects

• Phi Phenomenon : apparent movement between flashing stationary images

• http://www.yorku.ca/eye/balls.htm

• Stroboscopic: When images are flashed in sequence to create the illusion of continuous movement

• “cell animation” • http://www.youtube.com/watch?v=XeWIhWiT6bE

EMOTIONS AND MOTIVATION

• Influence our attention and perception

PERCEPTUAL SET

• Experience builds expectations which direct perceptions

• 2 minutes study and look for a pattern