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Sensation II: Gathering and Organizing Information

1. Properties of the physical stimulus for vision, that is light:

        a.  Intensity

        b.  Wavelength

        c.  Visible spectrum

2. How does the human visual system GATHER information?

a. Evolution of the 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.