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 ODUL E 07 : P ERCEPT ION

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 ODUL E 07 : P ERCEPT ION

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 ODUL E 07 : P ERCEPT ION

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