Visual System

Question 1

Rods contain _____.

Answer 1

rhodopsin

Question 2

Rhodopsin is extremely sensitive to _____.

Answer 2

light

Question 3

Rods function _____ in dim light and _____ in bright light.

Answer 3

well, poorly

Question 4

Rods do not distinguish _____.

Answer 4

color

Question 5

Rods are located in the _____.

Answer 5

peripheral retina

Question 6

Cones contain _____.

Answer 6

iodopsin

Question 7

Iodopsin requires _____ to function.

Answer 7

bright light

Question 8

Cones function _____ in daylight and _____ dim light.

Answer 8

well, poorly

Question 9

Cones have three types of iodopsins to respond to _____.

Answer 9

different wavelengths of light

Question 10

Cones are located in the _____.

Answer 10

central retina (fovea)

Question 11

Receptive fields of rods are _____.

Answer 11

large

Question 12

Receptive fields of cones are _____.

Answer 12

small

Question 13

Many rods share a _____.

Answer 13

ganglion cell

Question 14

Fewer cones than rods attach to each _____.

Answer 14

ganglion cell

Question 15

In the _____ each cone has its own ganglion cell.

Answer 15

fovea

Question 16

_____ contact photoreceptors and bipolar cells.

Answer 16

Horizontal cells

Question 17

_____ contact bipolar and ganglion cells.

Answer 17

Amacrine cells

Question 18

Ganglion cells create _____ potentials.

Answer 18

action

Question 19

When light strikes rhodopsin, _____ is activated.

Answer 19

retinal (RPE65)

Question 20

Leber’s congenital optic degeneration

Answer 20

RPE65 (retinal) is defective
photoreceptors degenerate
patient goes blind

Question 21

Light closes sodium channels, causing _____.

rods are turned off

Answer 21

hyperpolarization

Question 22

Lateral inhibition

Answer 22

inhibition of connected bipolar cells produces contrast

Question 23

LGN (lateral geniculate nucleus) of the thalamus has _____ cell types.

Answer 23

three

Question 24

Parvocellular cells consist of _____ dorsal layers and are _____ cells with _____ receptive fields.

Answer 24

four, small, small

Question 25

Magnocellular cells consist of _____ ventral layers and are _____ cells with _____ receptive fields.

Answer 25

two, large, large

Question 26

Koniocellular cells consist of layers with _____ cells, between _____ layers.

Answer 26

very small, main (P & M)

Question 27

Most visual information first arrives in the _____.

Answer 27

Primary visual cortex (V1) | in occipital cortex

Question 28

Brain maps of visual space are mostly devoted to the _____.

Answer 28

fovea

Question 29

Simple cells are _____.

Answer 29

line detectors

Question 30

Simple cells are more responsive to _____, than to static, steady illumination or diffuse illumination.

Answer 30

flashes of light

Question 31

Complex cells are concerned more with _____ than with their precise localization.

Answer 31

recognizing external objects

Question 32

Simple cortical cells, also called _____, respond to an edge or bar of a particular _____.

Answer 32

bar or edge detectors | width, orientation, and location

Question 33

Complex cortical cells respond to _____, but may be located _____ in the visual field.

Answer 33

a bar of a particular width and orientation | anywhere

Question 34

_____ receive input from neurons in lateral geniculate nucleus.

Answer 34

Simple cortical neurons

Question 35

_____ receive input from simple cells.

Answer 35

Complex cortical neurons

Question 36

Visual cortical cells do a _____ of the luminosity variations in a scene.

Answer 36

frequency analysis

Question 37

Different visual cortical cells have different _____.

Answer 37

sensitivities

Question 38

Visual cortical cells can detect not just _____ but _____ of luminosity change.

Answer 38

edges, grades

Question 39

Area V1 (primary visual cortex) Is organized in _____ and _____.

Answer 39

columns, slabs

Question 40

An ocular dominance column is a region of cortex with _____ from one eye.

Answer 40

greater synaptic input

Question 41

Much of vision is _____ from what is actually 'seen'.

Answer 41

extrapolating (predicting)

Question 42

Cells in inferotemporal cortex respond to _____, including _____ we have learned to recognize.

Answer 42

complex forms, forms

Question 43

Receptive fields in IT cortex develop through _____ and _____.

Answer 43

experience, learning

Question 44

Hierarchy of visual processing

Answer 44

From simple edges and borders to complex forms as you move from V1 to IT.

Question 45

The M-channel (magnocellular pathway) is _____ selective, _____ sensitive for movement, and has no _____ sensitivity (analysis of object motion)

Answer 45

orientation, directional, color

Question 46

The P-IB channel (parvocellular interblob pathway) has high _____ sensitivity, no _____ sensitivity, and _____. (analysis of object shape)

Answer 46

orientation, color, small receptive fields

Question 47

The blob channel (parvocellular blob and koniocellular pathway) has _____ sensitivity and no _____ sensitivity. (analysis of object color)

Answer 47

color, orientation

Question 48

Trichromatic hypothesis

Answer 48

Three types of cones Each cone responds to a part of the spectrum Each cone has a separate pathway to the brain

Question 49

Opponent-process hypothesis

Answer 49

Three color axes (opposed pairs of colors) red - green yellow - blue white - black

Question 50

Akinetopsia

Answer 50

Motion blindness

Question 51

Opponent Process: Cells in the _____ and thalamic _____ layers fire to some _____, and are inhibited by others.

Answer 51

retinal ganglion, parvocellular, wavelengths

Question 52

Micropsia causes objects in the visual field to appear _____ than normal.

Answer 52

smaller

Question 53

Macropsia causes objects in the visual field to appear _____ than normal.

Answer 53

larger

Question 54

_____ is cause by alternating micropsia and macropsia.

Answer 54

Alice in Wonderland Syndrome

Question 55

_____ results in the ability to see individual objects and the inability to perceive a visual scene as a whole.

Answer 55

Simultagnosia

Question 56

_____ results in seeing afterimages, both as a reduced amount of time required to form an afterimage, and an increased duration of the afterimage.

Answer 56

Palinopsia

Question 57

_____ results in normal speech, sensations, ability to use objects, and the the inability to name objects.

Answer 57

Visual agnosia

Question 58

Blindsight is due to minor pathways leading into the _____ that bypass _____.

Answer 58

``` extrastriate cortex (V2 through V5) straite cortex (V1) ```

Question 59

The _____ is associated with motion, representation of object locations, and control of the eyes and arms. (the 'where' pathway)

Answer 59

dorsal stream

Question 60

The _____ is associated with form recognition and object representation. (the 'what' pathway)

Answer 60

ventral stream

Question 61

Optic ataxia

Answer 61

The patient can't use visuospatial information to guide arm movements.

Question 62

Amblyopia

Answer 62

The loss of one eye's ability to see details. | lazy eye

Question 63

Hemispatial neglect

Answer 63

The patient is unaware of the contralesional half of space. | contralesional: the half of a patient's brain or body away from the site of a lesion

Question 64

Cells are classified as _____ or _____, depending on their _____.

Answer 64

simple, complex, receptive fields

Question 65

Vitamin _____ is a precursor to retinal.

Answer 65

A

Question 66

Hyperopia is known as _____ and can be corrected with a _____ lens.

Answer 66

farsightedness, convex

Question 67

Myopia is known as _____ and can be corrected with a _____ lens.

Answer 67

nearsightedness, concave

Question 68

The M-Channel is involved in _____ analysis.

Answer 68

motion

Question 69

The P-IB Channel is involved in _____ analysis.

Answer 69

shape

Question 70

The Blob Channel is involved in _____ analysis.

Answer 70

color

Question 71

The optic nerve is composed of _____.

Answer 71

ganglion cells