Paradox of Perception Which way was the train moving? A. Towards - - PowerPoint PPT Presentation

Perceiving the World

Part 1/3

The

Paradox

• f Perception

Which way was the train moving?

• A. Towards us

• B. Away from us

25 50 75 100

Towards Away

Too much information for our puny brains to process Not enough information to specify what is out there

A Paradox

• lfaction

(smell)

vision

(sight)

audition

(hearing)

gustation

(taste)

somatosensation

(touch)

proprioception

‘internally’ sensing your own body

thermosensation

feeling temperature

nociception

feeling pain

+

• lfaction

(smell)

vision

(sight)

audition

(hearing)

gustation

(taste)

somatosensation

(touch)

proprioception

‘internally’ sensing your own body

thermosensation

feeling temperature

nociception

feeling pain

+

Vision “Dominates” …in the brain too

…and we understand it best

Scientific publications on “visual perception”:

1.25 million

Scientific publications on “gustation”:

17,000

• Prof. Jason Fischer

Sensation

stimulation of our sense

• rgans by the world

Perception

• rganizing sensory

stimulation into a coherent picture of the world

“a small white sphere with an orange pattern on its surface”

spend the summer linking a camera to a computer and getting the computer to describe what it saw

1960s 2020

“a woman is throwing a frisbee in the park”

“a stop sign is on a road with a mountain in the background” “a little girl sitting on a bed with a teddy bear” “a large white bird standing in a forest”

“an airplane is parked on the tarmac at an airport” “a man wearing a hat on a skateboard”

Perception is Hard

Perceiving the World

Up next: Part 2/3

Perceiving the World

Part 2/3

“a man wearing a hat on a skateboard”

Perception is Hard

why did we think it would be easy?

Instinct Blindness

John Tooby Leda Cosmides

“The phenomenal experience

• f an activity as ‘easy’ or

‘natural’ often leads scientists to assume that the processes that give rise to it are simple. Seeing seems simple … precisely because there is a vast array of complex, dedicated computational machinery that makes this possible.”

Perception

X * Y = 8

X = ? You can’t!

Color & Lightness

Light alone is meaningless!

X * Y =

light hitting eye “true” color lighting conditions

“Unconscious Inferences”

X = ?

X * Y =

light hitting eye “true” color lighting conditions

“Unconscious Inferences”

X = ?

X * Y =

light hitting eye “true” color lighting conditions dark shadow white

X * Y =

light hitting eye “true” color lighting conditions bright light black

X * Y = 700nm

light hitting eye “true” color lighting conditions

X * Y = 700nm

light hitting eye “true” color lighting conditions

“Unconscious Inferences”

Light alone is meaningless!

X * Y =

light hitting eye “true” color lighting conditions

“Discounting the Illuminant”

3D Space

The world is 3D, but your retina is 2D!

X / Y =

size of retinal image true size distance

“Cues” to Size & Depth

Linear Perspective

Ponzo Illusion

Motion

Occlusion

Occlusion Perspective Motion …

Perceiving the World

Up next: Part 3/3

Perceiving the World

Part 3/3

Occlusion Perspective Motion …

The Paradox

• f Perception

Too much information for our puny brains to process Not enough information to specify what is out there

The Paradox

• f Perception

Too much information for our puny brains to process Not enough information to specify what is out there

Magnification Attention Magnification Attention

“Map” of body

• n the brain

Cortical Magnification

increased sensitivity

Fovea Periphery Periphery

{ {

Fovea

{ { Magnification Attention

Magnification Attention

William James

Attention … is the taking possession by the mind, in clear and vivid form, of

• ne out of what seem

several simultaneously possible objects or trains

• f thought

(1842-1910)

Attention Awareness

“Change Blindness”