Transcript Two Views of Perception

Two Views of Perception:
•Bottom-up processing:
-Low-level
-Feature driven
•Top-down processing
-Knowledge driven
-Unconscious inference (Helmholtz)
What do you see in this picture?
Vertical Line Stimulating
Receptive Field of Single Cell
Stimulation of a Single Cell by Downward Motion
BRIGHTNESS CONTRAST
Stimulus
Luminance
Profile
Mach Bands - Edge
Enhancement Illusion
How the Eye Accentuates Edges
Mach Bands
Recording From a Single Cell of the Visual Cortex
Frequency of Firing of Single Receptor in
Response to Stimuli of Different Amplitude
Inhibitory Effects of Stimulating Adjacent Receptor
Simple Cell in Visual Cortex
Complex Cell of Visual
Cortex
On-Off and Center Cells (Retina)
How the Visual System Responds to Edges
Lateral Inhibition
Excitatory & Inhibitory
Cells
Which column
is largest?
Which Line is Longer?
Which lines are parallel?
Are lines a and b parallel?
Which Line is Longer?
Which central dot is larger?
Necker Cube
What is This a Picture of?
Excitatory & Inhibitory
Cells
Bottom-up Perception
Which woman is taller?
Binocular Cues for Depth
•Convergence
•Binocular disparity
Monocular Cues for Depth
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Interposition
Linear perspective
Height in vertical plane
Texture
Shadow
Relative motion
Visual Angle
Interposition.
Which is closer? A or B?
A
B
Which column
is largest?
Linear Perspective
Which red line is bigger?
Which
bigger?
Whichred
redline
lineis is
bigger?
Linear Perspective
Height in Visual Field
Texture gradients
Texture Gradient
Which woman is taller?
“AMES”Room
Direction of Shadow
Haze
Haze
Shading
Relative Motion
Moon Illusion
Moon Illusion
Moon Illusion
Pop out effect