TransductionConversion of one form of

energy to another.How is this important when studying sensation?

Stimulus energies to neural impulses.

For example:

Light energy to vision.

Chemical energy to smell and taste.

Sound waves to sound.

Vision

We only use light energy to see.

What makes up a light wave?

Wavelength

• The distance from the peak of one light wave to the peak of the next.

•The distance determines the hue (color) of the light we perceive.

Intensity

The amount of energy in a light wave.

Determined by the height of the wave.

The higher the wave the more intense the light is.

Structure of the Eye

Nearsighted Vision

Farsighted Vision

The Retina

Feature Detection

The concept that specific nerve cells in the brain respond to specific features of the stimulus, such

as shape angle or movement.

Parallel Processing• The processing of several aspects of a

problem simultaneously.

Color Motion Form Depth

How do we see in color?

What color is this dragon?

Color

• The dragon is anything but red.

• The dragon rejects the long wavelengths of light that to us are red- so red is reflected of and we see it.

• Also, light has no real color.

• It is our mind that perceives the color.

Two major color theories

Young-Helmholtz Trichromatic (three color) Theory

• Realized that any color can be created by combining the light waves of three primary color-

•So they guessed that we have 3 different types of receptor cells in our eyes. Together they can pick any combination of our 7 million color variations.

•Most colorblind people simply lack cone receptor cells for one or more of these primary colors.

Opponent-Process Theory• We cannot see certain colors together in

combination (red-green, blue-yellow, and white-black). These are antagonist/ opponent colors.

Tube and marble example.