Sensation

• Input of sensory information

• Process of receiving, converting, and transmitting information from the outside world

Perception-Key Concepts

1. Selection

2. Organization

3. Interpretation

4. Subliminal perception and ESP

Figure-Ground Differentiation• Major Gestalt

principle of perceptual organization

• We divide world into 2 parts

1.Figure• Has shape &

location in space

2.Ground• Has no definite

shape and seems to continue beyond figure

Modeled after a ppt slide created by Dr. Kevin Richardson in 1998 and made available through the American Psychological Society

Gestalt Laws of Perceptual Grouping – Top-Down

Gestalt Laws of Perceptual Grouping – Top-Down

• How do we group objects perceptually?

• Several principles:

– Similarity– Proximity– Continuation– Simplicity– Closure

• How do we group objects perceptually?

• Several principles:

– Similarity– Proximity– Continuation– Simplicity– Closure

Modeled after a ppt slide created by Dr. Kevin Richardson in 1998 and made available through the American Psychological Society

SimilaritySimilarity

Similarity grouping suggests horizontal columns

Similarity grouping suggests horizontal columns

Proximity

Proximity Grouping Suggests Vertical Columns

ContinuationContinuation

We see a square even though its corners are missing

We see a square even though its corners are missing

SimplicitySimplicityThe lines are naturally grouped as a 3D cube.

The lines are naturally grouped as a 3D cube.

The lines are naturally grouped as a 2D pentagon.

The lines are naturally grouped as a 2D pentagon.

ClosureClosure Closur

e

Perceptual Constancies•Does our perception of

objects around you change if objects get closer or farther away, or if they are moving?

•No! No! No! No! No! No! No!

•Why?– Because of perceptual constancies

Modeled after a ppt slide created by Dr. Kevin Richardson in 1998 and made available through the American Psychological Society

Size Constancy

Ponzo Illusion: line in the distance appears larger

Click here to see many other famous illusions

Arranged by Gordon Vessels 2005

Retinal Size != Apparent Size

• Distance cues: relative size of elements, separation, density, clarity, background

The Ames Room

Müller-Lyer Lines• Eye-movement theory: Arrowheads

influence extent of eye movements

Müller-Lyer Lines Revisited

• The same illusion through perspective cues

Just plain cool illusions!Click Here

All lines below are straight; distorted pattern created by the

tiny squares

Click here to see inversion illusions on website

Café wall illusion