The Science of Illusions

May 7, 2013

Cedar RienerAssistant Professor of Psychology

Randolph-Macon CollegeTwitter: @criener

Science Pub RVA

Illusions are Everywhere!

Perception

Attention

Memory

Happiness

Decision-Making

Language

Conscious Will

Illusion of Being There

Illusion of Being

Illusions are Informative

How we see it wrong -> How vision works

Visual Illusions Show Decisions

• We are interested in surface colors, object shapes

• But color and shape are not on the retina

• We guess at color and shape

Brightness is an Illusion

Which square is a lighter gray?

Illusions and Science: Brusspuporiginal illusion: Adelson Checkerboard

Brightness is a Decision

Luminance = illumination/reflectance

luminance

illumination

reflectance

Shape is an Illusion

Ames Window

Belgian Rock Band: Goose

Music Video for “British Mode”

Directed by Keith Schofield

Attention

We only see what we pay attention to

Attention movies

Memory is an Illusion

Listen to these words

Your memories change every time you remember

Not “record, rewind and play”

Which were on the previous list?

• Bed• Paper• Keyboard• Door• Drowsy• Awake• Doctor • Dream

• Sleep• Mouse• Camera• Box• Hospital• Rest• Skin• Nurse

Illusions are Everywhere (Review)

• Vision – Color/Brightness and shape are guesses and decisions

• Attention – We ignore most of what is out there• Memory – We recreate our memories every

time we remember

Illusions inform us of limits

Image on the eye

Attention

Memory} Constrained, short, sparse

But we’re good enough, smart enough…

To solve the common problems of human life (among the hardest engineering problems ever):

• Understanding and producing human speech• Walking• Object Perception (recognizing words, faces)