CH5 VISION

Question 1

How far one sees is dependent on how far light travels before it strikes one’s eyes

Answer 1

Visual Coding

Question 2

This states that activity by a particular nerve always conveys the same type of information to the brain

Answer 2

Law of specific nerve energies

Question 3

___ is the mechanism of communication within (internal) while ____ is the mechanism of communication between (external) to the neurons.

Answer 3

electrical, chemical

Question 4

Is the central portion of the retina and allows for acute and detailed vision

Answer 4

The Fovea

Question 5

most abundant in the periphery of the eye and respond to faint light (120 million per retina)

Answer 5

Rods

Question 6

most abundant in and around the fovea (6 million per retina)

Answer 6

Cones:

Question 7

Two major interpretations of color vision

Answer 7

Trichromatic theory/Young-Helmholtz theory

Opponent-process theory

Question 8

Color perception occurs through the relative rates of response by three kinds of cones

Answer 8

Trichromatic Theory

Question 9

the ability to recognize color despite changes in lighting, is not easily explained by these theories

Answer 9

Color constancy

Question 10

An impairment in perceiving color differences

Answer 10

Color Vision Deficiency

Question 11

Chemicals contained by both rods and cones that release energy when struck by light

Answer 11

Photopigments

Question 13

Mostly located in or near the fovea

Have smaller cell bodies and small receptive fields

Highly sensitive to detect color and visual detail

Answer 13

Parvocellular Neurons

Question 14

Distributed evenly throughout the retina

Have larger cell bodies and visual fields

Highly sensitive to large overall pattern and moving stimuli

Answer 14

Magnocellular Neurons

Question 15

Have small cell bodies

Found throughout the retina

Have several functions, and their axons terminate in many different places

Answer 15

Koniocellular Neurons

Question 16

receives information from the lateral geniculate nucleus and is the area responsible for the first stage of visual processing

Answer 16

visual cortex (area V1)

Question 17

refers to the path that goes through temporal cortex

The “what” path

Specialized for identifying and recognizing objects

Answer 17

ventral stream

Question 18

refers to the visual path in the parietal cortex

The “how” path

Important for visually guided movements

Answer 18

dorsal stream

Question 19

can see where objects are but cannot identify them

Answer 19

Ventral stream damage

Question 20

can identify objects but not know where they are

Answer 20

Dorsal stream damage

Question 21

A method of perceiving distance in which the brain compares slightly different inputs from the two eyes

Relies on retinal disparity or the discrepancy between what the left and the right eye sees

The ability of cortical neurons to adjust their connections to detect retinal disparity is shaped through experience

Answer 21

Stereoscopic Depth Perception

Question 22

A condition in which the eyes do not point in the same direction

Usually develops in childhood

Also known as “lazy eye”

Answer 22

Strabismus

Question 23

The inability to recognize objects despite satisfactory vision

Caused by damage to the pattern pathway usually in the temporal cortex

Answer 23

Visual Agnosia

Question 24

receives information from area V1, processes information further, and sends it to other areas

Answer 24

visual cortex (area V2)

Question 25

The impaired ability to recognize faces

Occurs after damage to the fusiform gyrus of the inferior temporal cortex

The fusiform gyrus responds much more strongly to faces than anything else

Answer 25

Prosopagnosia

Question 26

The inability to determine the direction, speed and whether objects are moving
Likely caused by damage in area MT

Answer 26

Motion Blindness

Question 27

Several mechanisms prevent confusion or blurring of images during eye movements

Saccades are a decrease in the activity of the visual cortex during quick eye movements

Neural activity and blood flow decrease 75 milliseconds before and during eye movements

Answer 27

Saccades