Exam 2 - Vision

Question 1

Hue

Answer 1

determine by wavelength (we see between 380-760), color

Question 2

Brightness

Answer 2

determined by the intensity of the electromagnetic radiation, intensity/brightness of color

Question 3

Saturation

Answer 3

determined by the purity of the light wave, purity of color

Question 4

Orbits

Answer 4

bony pockets that hold the eye

Question 5

Sclera

Answer 5

white portion of the eye

Question 6

Conjunctiva

Answer 6

mucous membranes that line the eyelid and hold the eye muscles

Question 7

Cornea

Answer 7

transparent, where light first enters before entering pupil

Question 8

Pupil

Answer 8

constricts or dilates to let different amounts of light in, where light enters the eye

Question 9

Iris

Answer 9

colored portion of the eye, muscle that controls pupils - controlled by the ANS

Question 10

Lens

Answer 10

change shape to change the distance at which you can see

Question 11

Accommodation

Answer 11

changes in the thickness of the lens by the ciliary muscles, that focus images or near or distant objects on the retina

Question 12

The receptive fields of most retinal ganglion cells are roughly:
A) square
B) round
C) rectangular
D) perpendicular

Answer 12

B

Question 13

Simple cells of the primary visual cortex:
A) have receptive fields with static “on” and “off” areas that are separated by a straight edge.
B) do not have receptive fields.
C) have receptive fields that cannot be divided into static “on” and “off” areas.
D) have two receptive fields.

Answer 13

A

Question 14

Primary visual cortex is in the:
A) parietal lobe.
B) temporal lobe.
C) occipital lobe.
D) frontal lobe.

Answer 14

C

Question 15

A.T. is a woman with damage to her dorsal visual stream. She:
A) has little difficulty making accurate movements under visual control.
B) has substantial difficulty making accurate movements under visual control.
C) has substantial difficulty consciously recognizing objects.
D) also has damage to her inferotemporal cortex.

Answer 15

B

Question 16

With respect to vision, wavelength is to intensity as:
A) vision is to audition.
B) wavelength is to color.
C) color is to brightness.
D) color is to loudness.

Answer 16

C

Question 17

Light enters the human eye through an opening in the iris called the:
A) cornea.
B) fovea.
C) pupil.
D) retina.
E) sclera.

Answer 17

C

Question 18

High-acuity vision is mediated by the :
A) optic disk.
B) blind spot.
C). Fovea
D) choroid.

Answer 18

C

Question 19

The receptive field of a visual neuron is the area of the:
A) striate cortex within which stimulation can activate the neuron.
B) striate cortex within which stimulation can inhibit the neuron.
C) visual field within which the suitable visual stimulus can influence the firing of the
neuron.
D) retina within which stimulation with diffuse light can activate the neuron.

Answer 19

C

Question 20

Retina

Answer 20

where photoreceptors are located

Question 21

Optic Chiasm

Answer 21

where the optic nerves meet

Question 22

Cones, what type of light do they see, where are they found?

Answer 22

• daytime vision
• color
• only found at the fovea

Question 23

Rods, what type of light are they used for, and where are they located?

Answer 23

• nighttime vision
• dim light
• found on the periphery of the back of the eye

Question 24

Blind spot, what is completion?

Answer 24

• no receptors where information exits the eye
• where the visual system uses information from cells around the blind spot to fill in the space

Question 25

Fovea, what photoreceptors are here?

Answer 25

• high acuity area at center of retina
• only cones are here

Question 26

What are the three retinal layers?

Answer 26

1. photoreceptors
2. bipolar cells
3. ganglion cells

Question 27

On ganglion cell

Answer 27

light has to fall on the center

Question 28

Off ganglion cell

Answer 28

light has to fall on the periphery

Question 29

On/off ganglion cell

Answer 29

light has to shine on both the periphery and center

Question 30

Trichromatic theory of color vision

Answer 30

• proposes 3 types of receptors, each with a different spectral sensitivity
• one that responds to red, a second to green, and a third to blue

Question 31

What is the opponent process theory?

Answer 31

• 2 different classes of cells encoding color, and another class encoding brightness
• each encodes two complementary color perceptions

Question 32

Simple cells

Answer 32

• orientation and location
• sensitive cell in the middle of the visual field

Question 33

Complex cells

Answer 33

• motion sensitive
• light or dark background, can be seen anywhere in the visual field

Question 34

Hypercomplex cell

Answer 34

responds to the presence of a line segment with a particular orientation that ends at a particular point within a cell’s receptive field

Question 35

What is a scotoma?

Answer 35

damage to an area of primary visual cortex that causes loss of eyesight

Question 36

Dorsal stream, what does it start and end with?

Answer 36

• spatial location
• beings with striate cortex and ends with the posterior parietal cortex

Question 37

Ventral stream, what does it start and end with?

Answer 37

• perception of form
• begins with the striate cortex and ends with inferior temporal cortex

Question 38

What is color constancy?

Answer 38

relatively constant appearance of the colors of objects viewed under varying lighting conditions

Question 39

Visual agnosia, what is it caused by?

Answer 39

deficits in visual perception in the absence of blindness, caused by brain damage

Question 40

Magnocellular layers

Answer 40

• responsive to movement
• input from rods

Question 41

Parvocellular layers

Answer 41

• color, detail, and still or slow objects
• input from cones

Question 42

Protanopia

Answer 42

red cones have green in them

Question 43

Deuteranopia

Answer 43

green cones have red in them

Question 44

Tritanopia

Answer 44

lacks blue cones

Question 45

Primary visual cortex

Answer 45

receives most of its input from the LGN

Question 46

Secondary visual cortex

Answer 46

receives most of its input from primary visual cortex

Question 47

Visual association cortex

Answer 47

receives input from secondary visual cortex and other secondary sensory systems

Question 48

Achromatopsia, what is it caused by?

Answer 48

• inability to discriminate among different hues (can only see grays and blacks)
• caused by damage to the visual association cortex

Question 49

Inferior temporal cortex

Answer 49

highest level of the ventral stream where recognition of particular objects takes place

Question 50

Apperceptive visual agnosia

Answer 50

failure to perceive objects (don’t recognize objects visually)

Question 51

Associative visual agnosia

Answer 51

inability to identify objects that are perceived visually (asked to draw a picture, but when looking at the picture they wont know what it is)

Question 52

Prosopagnosia

Answer 52

Failure to recognize particular people by the sight of their faces

Question 53

Fusiform face area, this region is part of what?

Answer 53

region of the extrastriate cortex, involved in perception of faces and other objects

Question 54

What is the visual pathway?

Answer 54

1. retina
2. superior colliculi
3. lateral geniculate nucleus
4. primary visual cortex
5. secondary and association areas

Question 55

Akinetopsia

Answer 55

deficiency in the ability to see movement progress in a normal smooth fashion

Question 56

Intraparietal sulcus

Answer 56

the end of the dorsal stream of the visual association cortex that is involved in perception of location, visual attention, and control of eye and head movements