Module 18: Vision/Parts of the EYE

Question 1

Opponent-Process Theory

Answer 1

The theory that opposing retinal processes (red-green, yellow-blue,white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

Question 2

Young-Helmholtz Trichromatic (three-color) Theory

Answer 2

The theory that the retina contains three different color receptors- one most sensitive to red, one to green, one to blue-which, when stimulated in combination, can produce the perception of any color

Question 3

What is the visual processing process?

Answer 3

Scene -> Retinal Processing -> Feature Detection -> Parallel Processing -> Recognition

Question 4

Parallel Processing

Answer 4

The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision.
- Contrasts with the step-by-step (Serial)

Question 5

Feature Detectors

Answer 5

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

Question 6

Fovea

Answer 6

The central focal point in the retina, around which the eye’s cones cluster

Question 7

Blind Spot

Answer 7

The point at which the optic nerve leaves the eye, creating a “blind”spot because no receptor cells are located there

Question 8

Optic Nerve

Answer 8

The nerve that carries neural impulses from the eye to the brain

Question 9

Cones

Answer 9

Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or well-lit conditions. The cones detect fine detail and give rise to color sensations.

Question 10

Rods

Answer 10

Retinal receptors that detect black, white, and grey; necessary for peripheral and twilight vision, when cones don’t respond

Question 11

Accommodation

Answer 11

The process by which the eye’s lens change shape to focus near or far objects on the retina

Question 12

Retina

Answer 12

The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

Question 13

Lens

Answer 13

The transparent structure behind the pupil that changes shape to help focus images on the retina

Question 14

Iris

Answer 14

A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

Question 15

Pupil

Answer 15

The adjustable opening in the center of the eye through which light enters

Question 16

Intensity

Answer 16

The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude.

Question 17

Hue

Answer 17

The dimension of color that is determined by the wavelength of light; what we know are the color names blue, green, etc.

Question 18

Wavelength

Answer 18

The distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission