Psychology2016

106 CHAPTER 3

The Science of Seeing

has psychological

properties

is a physical

stimulus

seeing

light

brightness

color/hue

saturation

contains photoreceptors

has a blind spot

rods

cones

trichromatic theory—processing

by cones

opponent-process theory—processing

beyond cones (bipolar or ganglion cells

to LGN of thalamus)

right visual field → left side of each retina;

left visual field → right side of each retina

axons from temporal halves of each retina

project to visual cortex on same side of the

brain; axons from nasal halves project to

visual cortex on opposite side of the brain;

optic chiasm is point of crossover

is a form of electromagnetic radiation

with properties of both waves and particles

processed

by the eye

begins

with retinal

receptor cells

visual pathway

rods

cones

cornea

pupil

lens

retina

found in periphery of retina

“see” black and white or shades of gray

work well in low light

found all over but greatest density

in center of retina (fovea)

“see” colors

work best in bright light

primarily responsible

for color vision: two theories

retina → optic nerve → optic chiasm → optic

tract → LGN of thalamus → optic radiations

→ primary visual cortex

Concept Map L.O. 3.4, 3.5, 3. 6

Interactive

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Practice Quiz How much do you remember?

Pick the best answer.

1. Which of the following is largely determined by the length of a light
   wave?
   a. color
   b. brightness
   c. saturation
   d. duration


2. Aside from the lens, damage to the ____ can affect the eye’s
   ability to focus light.
   a. iris
   b. cornea
   c. pupil
   d. retina


3. In farsightedness, also known as __, the focal point
   is the retina.
   a. presbyopia; above
   b. myopia; below
   c. hyperopia; beyond
   d. presbyopia; in front of
   4. Colleen stares at a fixed spot in her bedroom using only one eye.
   After a while, what might happen to her vision?
   a. Any small object that crosses her visual field very slowly may at
   one point disappear.
   b. Any object that she focuses on will begin to rotate, first clock-
   wise, then counterclockwise.
   c. Objects will become more focused the longer she looks at them.
   d. Objects will become more distorted the longer she looks at them.
   5. What are the three primary colors as proposed by the trichromatic
   theory?
   a. red, yellow, blue c. white, black, brown
   b. red, green, blue d. white, black, red
   6. Which of the following best explains afterimages?
   a. trichromatic theory
   b. opponent-process theory
   c. color-deficient vision
   d. monochrome color blindness