1. Chapter 6 (C): Vision

2. Do-Now (Discussion)
Raise your hand if you are either nearsighted or farsighted.
What causes Nearsightedness (Myopia) and Farsightedness (Hyperopia)?

3. Transduction Transduction:
Conversion of one form of energy into another
Transformation of stimulus energies, such as sights, sounds, and smells into neural impulses the brain can interpret

4. The Stimulus Input: Light Energy
Visible
Spectrum

5. The Stimulus Input: Light Energy
Wavelength:
The distance from the peak of one light or sound wave to the peak of the next
Hue:
Dimension of color that is perceived
Determined by the wavelength of light
E.g. green, blue

6. Different wavelengths of light result
Wavelength (Hue)
Violet
Indigo
Blue
Green
Yellow
Orange
Red
400 nm
700 nm
Short wavelengths
Long wavelengths
Different wavelengths of light result
in different colors.

7. The Stimulus Input: Light Energy
Intensity:
The amount of energy in a light or sound wave
Determined by the wave’s amplitude
E.g. brightness (vision), loudness (hearing)

8. Intensity (Brightness)
Blue color with varying levels of intensity.
As intensity increases or decreases, blue color
looks more “washed out” or “darkened.”

9. Accommodation Accommodation:
The process by which the eye’s lens changes shape to focus near or far objects on the retina

10. The Eye

11. The Retina

12. Receptors in the Human Eye

13. Demonstration: Rods and Cones
When looking at
something through your peripheral vision,
why is it difficult to
determine its color?

14. The Optic Nerve, Blind Spot, and Fovea

15. Demonstration: Test Your Blind Spot
Directions:
Looking at your sheet, close your left eye, and fixate your right eye on the black dot. Move the page towards your eye and away from your eye. At some point the car on the right will disappear due to a blind spot.

16. Visual Information Processing

17. Parallel Processing

18. From Sensation to Recognition

19. Young-Helmholtz Trichromatic Theory and Color Blindness
Color Blindness is a genetic disorder,
in which people are blind to green or red colors.
This supports the Trichromatic Theory.
Ishihara Test

20. Opponent-Process Theory

21. Opponent-Process Theory

22. Review
When looking at an object, what determines the color and brightness that we perceive?
Discuss the path in which light travels between entering the eye and reaching the brain.
What is parallel processing?
Differentiate between the Young-Helmholtz Trichromatic Theory and the Opponent-Process Theory of vision.