Computationally Modeling of Perception

Dr. Zimmerman, PhD

Color Vision, Motion Perception and the Brain

Dr. Zimmerman, PhD

Overview of my talk

1) Introduction

2) My Background

3) Show Illusion

4) Models of Color Perception

5) Color and Motion

6) What this all means

Introduction

My objective with this talk is to let you know that you can go almost anywhere with an Electrical Engineering degree.

1) Applied mathematics and statistics

2) Modelling physical systems

3) Using Mathematics and Science creatively

My Background

1) BS at the University of Utah in EE

2) PHD at the University of Minnesota in EE

3) Post-doc at Harvard in Experimental Psych

4) Professor at Tulane University in New Orleans

My interests have flowed into trying to understand how we "see"

The Illusion

The Illusion

What you should have seen:

When the orange light was on, the motion of the wheel should seem to slow down or stop. Equiluminant - color only

When the orange light was off the wheel should seem to spin normally

Luminant - color and luminance

Cone Vision - Helmholtz

Color sensitive transducers on your retina called cones. They have overlapping spectral sensitivities: Red, Green, and Blue

wavelength

RG

B

Note: This has nothing to do with night vision which uses separate transducers called rods

Color Opponency - Hering

The color transducers seemed to be hooked up in a funny way to form informational channels: Luminance channel, R/G channel, and B/Y channel.

Lum = R + G

R/G channel = R - G

B/Y channel = B - (R + G) or B - Lum

How The Illusion is created

Lum = R + G

R/G channel = R - G

B/Y channel = B - (R + G) or B - Lum

Notice that the luminance is integrally intertwined in the B/Y chromatic channels. I use this fact of your perception and the different color filters to isolate this chromatic channel.

What does this mean perceptually?

Luminance Channel - better at seeing motion, better at perceiving space.

Chromatic Channels - perceive motion as moving more slowly, has trouble locating objects in space.

Normally in the world, both are happening at the same time. What are the consequences?

What does this mean

1) We are not cameras, we are complex information processing machines.

2) Since we are all subtly constructed a little different, there will be good as well as bad motion perceivers.

3) Our misunderstanding of our own perception processes can lead to trouble.

What does this mean for you?

1) Your EE skills can map onto problems way outside of classical Electrical Engineering

2) Don't be afraid to use those skills, or to step into areas that are not called engineering.

3) Many problems and solutions exist at the boundary between engineering and the world.

Questions