Perception and Reality Things Are Not Always As They Seem...

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Perception and RealityThings Are Not Always As
They Seem...

• Is Seeing Always Believing?

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Is Seeing Always Believing?Overview

• Still Visual Illusion Slideshow
• Forced-choice Worksheet
• Answer the questions on the handout as we move
  through the slideshow
• There are no right or wrong answers right now
  just answer what the pictures look like to YOU
• Discussion of Answers
• As we go through the illusions a second time
• How could we double-check (verify) whether what
  you (or anyone else) are seeing is what is
  actually there?

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Hermann Grid
Do you see any black dots (circles)?
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Hering Illusion
Are the Two Vertical Lines Straight or Curved?
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Café Wall Illusion

• Are the Gray Lines Below All Parallel? Are the
  blocks all the
• same size? Are the blocks moving?

(b) Are the Gray Lines Below All Parallel (or
slanted)? Are the Blocks Rectangles?
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Checker-Shadow
Which Square is Darker, A or B?
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Neon Color Spreading

• Do you see a Red ball when there are no Black
  lines?
• Do you see a Red ball when the Black lines
  appear?

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Retinex Color
How many colors do you see? List the colors.
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One More Look

• As we go through the illusions again, for each
  example discuss the following as a class
• What did you see?
• What did everyone else see?
• How can we double-check (verify) whether what you
  (and everyone else) are seeing is what is
  actually there?

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Hermann Grid
How Can We Test It?
Do you see any black dots (circles)?
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Hering Illusion
Are the Two Vertical Lines Straight or Curved?
How Can We Test It?
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Café Wall Illusion

• Are the Gray Lines Below All Parallel? Are the
  blocks all the
• same size? Are the blocks moving?

(b) Are the Gray Lines Below All Parallel? Are
the Blocks Rectangles?
How Can We Test It?
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Checker-Shadow
Which Square is Darker, A or B?
How Can We Test It?
Do you agree this bar is the same
Luminance (shade of gray) from top to bottom?
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Neon Color Spreading

• Do you see a Red ball when there are no Black
  lines?
• Do you see a Red ball when the Black lines
  appear?

We Can Already See That the Black Lines
Cause Us to See Something That Is Not There
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Retinex Color
How many colors do you see? List the colors.
How Can We Test It?
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Retinex Theory of Color
The Cheeseburger is Really Just a Combination of
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Retinex Color
Dont Believe It? Take a Closer Look
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Conclusions

• Perception is Our personal view of the way the
  world is how it seems to each of us.
• Reality is the way the world actually is.
• Sometimes what we think is going on (perception)
  is incorrect (different than reality). How do we
  know?
• (a) other people can have different perceptions
  and show us how ours is incorrect,
• (b) our other senses can give different
  information,
• (c) we can compare it to perceptions of other
  things in the world we are more certain of (like
  a ruler).
• By understanding why we sometimes make
  mistakes, we might be able to avoid mistakes in
  the future