Sensation
3 Common Principles (cont.)
Interaction
Interaction in Time: Adaptation
Interaction in Space: Contrast
Perception
The fundamental question
Gestalt Psy. and the laws of Pragnanz
Perceptual Constancy
Across movement, shape, & size
Visual Illusions & Depth Percepetion
How do we move from bits and pieces of sensation to perceptual wholes?
Gestalt is a German word for "whole"--applied to this perspective because of belief that whole is greater than sum of the parts.
Laws of Pragnanz = Laws of organization.
Proximity
Contnuation
Closure
Similarity
Symmetry
Figure Ground
Sensations (i.e., the data) change, but perceptions remain the same. Three examples:
With head movement
Shape constancy
Size constancy
Retinal size is constant.
Apparent size changes as a function of perceived distance (i.e., depth cues).
On the horizon, depth cues suggest the moon is further away than when the moon is high in the sky.
If retinal size is constant, but depth cues suggest further away, brain concludes the moon must be bigger.