Illusions and Other Visual Defects
CITA 6016
Food Sensory Analysis
University of Puerto Rico
Food Science & Technology
Visual Illusions
Brain misinterpretation of the presented visual information
See http://www.michaelbach.de/ot/ for a full tour of examples
Count the black dots!
Are the wheels turning?
Which side is up?
Which end is closer to you?
Parallel or sloping lines?
How many legs?
Look at the dot. Where’s the haze?
Focus on the dot and move.
Are purple lines straight?
Which center is larger?
Ghostly dots?
Man or Liar?
How many tines in the fork?(two, but can you see three?)
More examples
What does this say? Look again.
Are the sides of the square curved or straight? Check with a straight edge.
More examples
How many colors?(two)
Are the diagonal lines parallel?
(yes)
Do you see a man playing a sax or a woman in shadow?
Can you see both an old lady and a
young lady?
Right or Left Brain
The brain is a great parallel processor for visual information.
Identifies differences Fill in blanks
…but can get in trouble
Identifies differences
Fill in blanks
Aoccdrnig to a rscheearch at an Elingsh
uinervtisy, it deosn't mttaer in waht oredr the
ltteers in a wrod are, the olny iprmoetnt tihng
is taht frist and lsat ltteer is at the rghit pclae.
The rset can be a toatl mses and you can
sitll raed it wouthit porbelm. Tihs is bcuseae
we do not raed ervey lteter by it slef but the
wrod as a wlohe
Internal fight
Blindness
Some people cannot see some colors
… can you?
NormalColorVision
Red/GreenColorBlind
Blue/YellowColorBlind
Blindness
NormalColorVision
Red/GreenColorBlind
Blue/YellowColorBlind
Blindness
NormalColorVision
Red/GreenColorBlind
Blindness
What numbers do you see?
What numbers do you see?
What numbers do you see?
What numbers do you see?
What shapes do you see?
What shapes do you see?
What shapes do you see?
What shapes do you see?
Carry Over Effects
Vision sensors saturate and keep “memory” of the previously seen image with contrasting colors
Look at the four dots for 10 seconds.
What do you see?
Try this one…
What do you see?
…and this one?
What do you see?
…and this one?
What do you see?
Conclusion
Don’t believe everything you see Be aware that panelists are human too and
may unadvertedly make mistakes