Vision Quiz (Chapter 6)

Question 1

Law of specific nerve energies

Answer 1

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

Question 2

Pupil

Answer 2

Light enters the eye through an opening in the center of the iris

Question 3

Retina

Answer 3

Light is focused by the lens and the cornea onto the rear surface of the eye. Lined with visual receptors

Question 4

Bipolar cells

Answer 4

Visual receptors that send messages to neurons,

Question 5

Ganglion cells

Answer 5

Cells that the bipolar cells send messages to.

Question 6

Amacrine cells

Answer 6

additional cells that receive information from bipolar cells and send it to other bipolar, ganglion or amacrine cells.
control the ability of the ganglion cells to respond to shapes, movements, or other specific aspects of visual stimuli.

Question 7

optic nerve

Answer 7

consists of the axons of ganglion cells that band together and exit through the back of the eye and travel to the brain.

Question 8

Blind spot

Answer 8

The point at which the optic nerve leaves the back of the eye, contains no receptors

Question 9

Fovea

Answer 9

central portion of the macula (center of the retina), allows for acute and detailed vision. Packed tight with receptors. Nearly free of ganglion axons and blood vessels.

Question 10

Midget ganglion cell

Answer 10

Each receptor in the fovea attaches to a single bipolar cell and a single ganglion cell

Question 11

photopigments

Answer 11

chemicals contained by both rods and cones that release energy when struck by light
11 cis-retinal bound to opsin and light convert to trans-retinal, light absorbed and activates second messengers

Question 12

Trichromatic theory

Answer 12

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

Question 13

opponent-process theory

Answer 13

suggests that we perceive color in terms of paired opposites; green-yellow, yellow-blue, black-white

Question 14

color constancy

Answer 14

the ability to recognize color despite changes in lighting

Question 15

retinex theory

Answer 15

suggests the cortex compares information from various parts of the retina to determine the brightness and color for each area.

Question 16

visual field

Answer 16

part of the world that you see before you can identify the color

Question 17

horizontal cells

Answer 17

cells in the eye that make inhibitory contact onto bipolar cells.

Question 18

lateral geniculate nucleus

Answer 18

part of the thalamus specialized for visual perception.

Question 19

later inhibition

Answer 19

reduction of activity in one neuron by activity in neighboring neurons.

Question 20

receptive field

Answer 20

part of the visual field that either excites or inhibits a cell in the visual system of the brain.

Question 21

Parvocellular neurons

Answer 21

mostly located in or near the fovea, have smaller cell bodies and small receptive fields,
are highly sensitive to detect color and visual detail.

Question 22

Magnocellular neurons

Answer 22

distributed evenly throughout the retina.
have larger cell bodies and visual fields.
are highly sensitive to large overall pattern and moving stimuli.

Question 23

Koniocellular neurons

Answer 23

have small cell bodies.

are found throughout the retina.

Question 24

primary visual cortex (area V1)

Answer 24

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

Question 25

blindsight

Answer 25

damage to V1. ability to respond to visual stimuli that they report not seeing.

Question 26

secondary visual cortex (area V2)

Answer 26

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

Question 27

Simple cells

Answer 27

Fixed excitatory and inhibitory zones.
The more light that shines in the excitatory zone, the more the cell responds.
The more in the inhibitory zone, the less the cell responds.

Question 28

Complex cells

Answer 28

Located in either V1or V2.
Have large receptive field that can not be mapped into fixed excitatory or inhibitory zones.
Responds to a pattern of light in a particular orientation and most strongly to a stimulus moving perpendicular to its access.

Question 29

End-stopped or hypercomplex cells

Answer 29

similar to complex cells but with a strong inhibitory area at one end of its bar shaped receptive field.
Respond to a bar-shaped pattern of light anywhere in its large receptive field, provided the bar does not extend beyond a certain point.

Question 30

feature detectors

Answer 30

in the visual cortex, neurons whose response indicate the presence of a particular feature/ stimuli

Question 31

inferior temporal cortex

Answer 31

contains cells that respond selectively to complex shapes but are insensitive to distinctions that are critical to other cells.

Question 32

shape constancy

Answer 32

the ability to recognize an object’s shape despite changes in direction or size.

Question 33

visual agnosia

Answer 33

inability to recognize objects despite satisfactory vision.

Question 34

prosopagnosia

Answer 34

inability to recognize faces, Occurs after damage to the fusiform gyrus of the inferior temporal cortex.

Question 35

middle-temporal cortex (MT/ V5)

Answer 35

responds to a stimulus moving in a particular direction

Question 36

medial superior temporal cortex (MST)

Answer 36

respond to expansion, contraction or rotation of a visual stimulus

Question 37

MST

Answer 37

Movement of an object relative to it’s background

Question 38

saccades

Answer 38

decrease in the activity of the visual cortex during quick eye movements

Question 39

motion blindness

Answer 39

inability to determine the direction, speed and whether objects are moving.

Question 40

retinal disparity

Answer 40

discrepancy between what the left and the right eye sees

Question 41

Strabismus

Answer 41

a condition in which the eyes do not point in the same direction, lazy eye

Question 42

Astigmatism

Answer 42

blurring of vision for lines in one direction caused by an asymmetric curvature of the eyes