Unit 3 - Vision

Question 1

The wavelength (distance from one wave peak to the next) of light determines…

Answer 1

Hue

Question 2

The amount of energy in light waves (intensity- determined by a waves amplitude) determines…

Answer 2

Brightness

Question 3

What is the function of the cornea?

Answer 3

• Where light enters the eye
• Protects the eye and bends light to provide focus

Question 4

What is the pupil?

Answer 4

• A small adjustable opening
• Light passes through the pupil after passing through the cornea

Question 5

What is the iris?

Answer 5

• Surrounds the pupil and controls its size
• A colored muscle that dilates or constricts in response to light intensity and emotions
  -When we are feeling amorous, our pupils dialate

Question 6

What is the lens?

Answer 6

• Located behind the pupil
• Focuses incoming light rays into an image on the retina by changing its curvature

Question 7

What is the retina?

Answer 7

• A multilayered tissue on the eyeballs sensitive inner surface

Question 8

The process by which the eyes lens changes shape to focus near or far objects on the retina is called…

Answer 8

Accommodation

Question 9

What are rods?

Answer 9

• Retinal receptors that detect black, gray, and white
• Located in periphery of retina
• Necessary for peripheral and twilight vision, when cones don’t respond
• Share bipolar cells with other rods, sending combined messages
• Sensitive to dim light

Question 10

What are cones?

Answer 10

• Retinal receptor cells that are concentrated near the center of the retina
• Function in daylight or in well-lit conditions
• Detect fine detail and give rise to color sensations
• Each transmits to a single bipolar sea to input from the fovea and these connections preserve the cones precise information, making them better able to detect the fine detail

Question 11

What is the optic nerve?

Answer 11

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

Question 12

What is the optic nerve made of

Answer 12

The axons of ganglion cells

Question 13

What is the blind spot?

Answer 13

• The point at which the optic nerve leaves the eye
• There are no receptor cells there, creating a blind spot

Question 14

What is the fovea?

Answer 14

The central focal point in the retina, around which the eyes cones cluster

Question 15

What is parallel processing?

Answer 15

• Th processing of many aspects of a problem simultaneously
• The brains natural mode of information processing for many functions.

Question 16

What are feature detectors?

Answer 16

• Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
• This helps explain why some people with poor vision may still be able to detect the presence of an object, as well as its shape and movement pattern

Question 17

What is the visual information process?

Answer 17

1. Scene
2. Retinal processing: Receptor rods —> bipolar cells —> ganglion cells
3. Feature detection: the brains response to specific lines, edges, and angles
4. Parallel processing: brain cell tans process combination information about motion, form, depth, color
5. Recognition: Brain interprets the constructed image based in information from stored images.

Question 18

What is the young-helmholtz trichromatic theory?

Answer 18

• The theory that the retina contains three different color receptors (red, green, and blue)
• when stimulated in combination, can produce the perception of any color

Question 19

What is the opponent process theory?

Answer 19

• The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision
• Ex: Some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green
• Explains reversed color afterimages

Question 20

When given a cluster of sensations, people tend to organize them into a _______

Answer 20

Gestalt: An organized whole

Question 21

What abilities is needed to form perception?

Answer 21

• Figure
• Ground
• Grouping

Question 22

What is the figure-ground relationship?

Answer 22

The organization of the visual field into the objects (the figures) that stand out from their surroundings (the ground)

Question 23

What is the grouping method and some examples?

Answer 23

The perceptual tendency to organize the stimuli into coherent groups.
- Examples: proximity, continuity, and closure

Question 24

What is depth perception?

Answer 24

• The ability to see objects in three dimensions although the images that struck the retina are two dimensional
• Allows us to judge distance
• Looked at in the visual cliff experiment by Eleanor Gibson and Richard Wal

Question 25

What are binocular cues?

Answer 25

• Depth cues, such as retinal disparity, that depend on the use of two eyes,

Question 26

What are monocular cues?

Answer 26

• Depth cues such as inter positional and linear perspective, available to either eye alone.
• Illustrates how the whole differs from the sum of its parts

Question 27

What is the phi phenomenon?

Answer 27

An illusion of movement created when two or more adjacent lights blink on and off in quick succession

Question 28

What is perceptual constancy?

Answer 28

Perceiving objects as unchanging even as illumination and retinal images change

Question 29

What is color constancy?

Answer 29

Receiving familiar objects as having consistent color even if changing illumination alters the wavelengths reflected by the object

Question 30

What is a visual cliff?

Answer 30

• A laboratory device for testing depth perception in infants and young animals

Question 31

What is retinal disparity?

Answer 31

• A binocular cue for perceiving depth
• By comparing images from the retinas in the two eyes, the brain computes distance
• The greater the disparity (difference) between the two images, the closer the object

Question 32

What is light-dark adaptation?

Answer 32

• When chemical changes in the rods and cones make the retina more sensitive to light

Question 33

What is perceptual adaptation?

Answer 33

• Our ability to adjust to an altered visual field
• Can occur though the use of glasses or goggles

Question 34

What is size constancy?

Answer 34

• Helps us understand that the size of an object remains the same even if the lighting, distance, or angle from which we see the object may change.
• Ex: The buildings may appear small to Shana because she is very far away, but size constancy allows her to perceive them as their normal (immense) size.

Question 35

What is relative motion?

Answer 35

• A monocular depth cue that makes stationary objects appear to move as we move.
• Ex: Sahn looking out the window of a moving car and perceiving the trees and houses moving

Question 36

What are photoreceptors?

Answer 36

• Cells located in the retina that convert light energy into nerve impulses

Question 37

What is vitreous humor?

Answer 37

• Gelatin-like substance that fills our eyes
• Creates the shape of the eye
• Helps to transmit light to the retina.