Sensation II: Gathering and Organizing Information
1. Properties of the physical stimulus for vision, that is light:
c. Visible spectrum
2. How does the human visual system GATHER information?
a. Evolution of the eye:
- Sensitive spots
- Compound eye
b. The human eye -- the retina; the fovea; the lens; the iris.
c. The visual receptor cells – rods and cones.
d. The DUPLEX THEORY OF VISION: We have two kinds of cells that are specialized for doing different things.
e. Visual acuity and visual sensitivity.
3. The visual pathway
a. Receptor cells
b. Ganglion cells – brightness contrast, lateral inhibition, and the center-surround organization of cells.
c. Cells in the thalamus – detect lines of different orientation.
d. Cells in the occipital cortex – detect more complex features like angles.
e. Higher levels
4. Color vision
a. Hue, brightness, and saturation
b. Color mixtures – subtractive versus additive
c. Complementary hues – red/green; blue/yellow
5. The Opponent Process Theory – three different types of cones.