Chapter 10: The Central Visual System

Question 1

() results in perception.

Answer 1

Neural processing

Question 2

Pathway serving conscious visual perception originates in the ().

Answer 2

retina

Question 3

Information received by the retina is actually formed as action potential in the ()

Answer 3

retinal ganglion cells (RGC)

Question 4

RGC axons pass through (3)

Answer 4

1. Optic nerve
2. Optic chiasm
3. Optic tract

Question 5

optic tract leads to ()

Answer 5

lateral geniculate nucleus (LGN)

Question 6

Ganglion cell axons from nasal retina cross in () (partial decussation).

Answer 6

optic chiasm

Question 7

() – all the information from one side

Answer 7

Hemifield

Question 8

Each optic nerve has 2 parts, each connected to 2 parts of retina: () -> allows each eye to see a part of opposite eye’s hemifield

Answer 8

nasal and temporal

Question 9

() – in both hemifields; intersection of hemifields that can be perceived by BOTH eyes

Answer 9

Binocular region

Question 10

Objects in the binocular region of the left visual hemifield will be imaged on the (1) retina of the left eye and on the (2) retina of the right eye

Answer 10

1. nasal
2. temporal

Question 11

all info about the left hemifield is directed to the () side of the brain

Answer 11

right

Question 12

after the partial decussations in the optic chiasm, info from one side of the binocular field (from both hemifields) is merged in each ()

Answer 12

LGN (transmission given to LGN via synaptic transmission)

Question 13

() – from outside to other part of brain (outside of retina)

Answer 13

Retinofugal

Question 14

Cutting of () - blindness in left hemifield (not including binocular field)

Answer 14

left optic nerve

Question 15

Cutting of () – complete blindness to the right side -> signals from right hemifield are not brought to visual cortex

Answer 15

left optic tract

Question 16

Transection of () – outside of vision field is blinded -> no peripheral vision

Answer 16

optic chiasm

Question 17

nonthalamic targets of the optic tract: () - role in biological rhythms, including sleep and wakefulness

Answer 17

hypothalamus

Question 18

Nonthalamic Targets of the Optic Tract: () in the midbrain - control size of the pupil, certain types of eye movement

Answer 18

Pretectum

Question 19

Nonthalamic Targets of the Optic Tract: () in the midbrain - orients the eyes in response to new stimuli—move fovea to objects of interest

Answer 19

Superior colliculus

Question 20

In the right LGN, the right eye (ipsilateral) axons synapse on LGN cells in layers (1); the left eye (contralateral) axons synapse on cells in layers (2).

Answer 20

1. 2,3, and 5
2. 1, 4, and 6

Question 21

in the LGN, () are between numbered layers

Answer 21

K layers

Question 22

Receptive fields of LGN neurons: almost identical to the () that feed them

Answer 22

ganglion cells

Question 23

() LGN neurons: large center-surround receptive fields with transient response

Answer 23

Magnocellular

Question 24

() LGN cells: small center-surround receptive fields with sustained response

Answer 24

Parvocellular

Question 25

Within all layers of the LGN, the neurons are activated by (1) and ON-center and OFF-center cells are (2)

Answer 25

1. only one eye 2. intermixed

Question 26

() provides 80% of the synaptic input to the LGN—role not clearly identified.

Answer 26

Primary visual cortex

Question 27

() provide modulatory influence on neuronal activity

Answer 27

Brain stem neurons

Question 28

other names of the primary visual cortex

Answer 28

1. V1 2. area 17 3. striate cortex

Question 29

Map of the visual field onto a target structure (seen in retina, LGN, superior colliculus, striate cortex)

Answer 29

retinotopy

Question 30

Central visual field (fovea) overrepresented in map (retinotopy) because ()

Answer 30

there are many more neurons in the V1 that receive input from the central retina than from the peripheral retina

Question 31

laminations of the striate cortex

Answer 31

layers I to VI

Question 32

spiny stellate cells in the striate cortex have (1), and are found in (2)

Answer 32

1. spine-covered dendrites 2. layer IVC

Question 33

pyramidal cells in the striate cortex are characterized by (1), and are found in (2)

Answer 33

1. spines and thick apical dendrites 2. layers III, IVB, V, VI

Question 34

() in the striate cortex lack spines and are found in all cortical layers -> form local connections

Answer 34

inhibitory neurons

Question 35

() typically send info to other parts of brain (can do this bc they have long axons/dendrites)

Answer 35

Pyramidal cells

Question 36

magnocellular LGN neurons project primarily to layer (1), which projects to cells in layer (2)

Answer 36

1. IVC-alpha 2. 4b

Question 37

parvocellular LGN neurons project to layer (1), which projects to cells in (2)

Answer 37

1. IVC-beta 2. layer 3

Question 38

() LGN axons make synapses primarily in layers I and III

Answer 38

koniocellular

Question 39

pattern for intracortical connection where in the retinotopic organization established in layer 4 is maintained

Answer 39

radial connections

Question 40

Interconnections between different radial columns via collateral branches in layer 3 pyramidal neurons

Answer 40

horizontal connections

Question 41

Hubel and Wiesel injected () into one eye in their experiment

Answer 41

radioactive proline

Question 42

Hubel and Wiesel's experiment revealed the action and presence of () -> some neurons are dominated by 1 eye

Answer 42

ocular dominance columns

Question 43

Ocular dominance column shows () -> receptive field can be dramatically changed

Answer 43

dramatic plasticity

Question 44

mitochondrial enzyme used for cell metabolism

Answer 44

Cytochrome oxidase

Question 45

(1): pillars of cytochrome oxidase-rich neurons in V1; usually centered on an ocular dominance column in ()

Answer 45

1. Blobs 2. layer IV

Question 46

Multiple center-surround cells generate a () receptive field -> only when many of the cells are stimulated are the upper layer (simple) cells fired

Answer 46

“bar-type”

Question 47

cells in layer IVC of the striate cortex are similar to ()

Answer 47

LGN celss

Question 48

cells in layer IVC-alpha of the striate cortex are insensitive to ()

Answer 48

wavelength

Question 49

cells in layer IVC-beta of the striate cortex have ()

Answer 49

center-surround color opponency

Question 50

Most neurons in striate cortex layers superficial to IVC are ().

Answer 50

binocular

Question 51

Most of receptive fields in the retina, LGN and layer IVC are ().

Answer 51

circular

Question 52

Outside of layer IVC, many neurons in V1 respond best to an ().

Answer 52

elongated bar of light

Question 53

describe orientation selectivity in striate cortex neurons

Answer 53

responsiveness of neurons (rate of AP firing) is maximum when the object being perceived is in a preferred orientation

Question 54

Preferred orientation progressively ()

Answer 54

shifts across the layer IVC

Question 55

() responds to different orientation of bar stimulations

Answer 55

Orientation column

Question 56

Neuron fires action potentials in ()-dependent response to moving bar of light.

Answer 56

direction

Question 57

A subset of the orientation-selective cells in V1 shows () -> specialized for the analysis of object motion

Answer 57

direction selectivity

Question 58

Receptive Field of (): binocular, orientation-selective, elongated ON or OFF area flanked with antagonistic surround

Answer 58

Simple cells

Question 59

Receptive field may be composed of several LGN inputs from cells with ().

Answer 59

aligned center-surround receptive fields

Question 60

Receptive Fields of (): binocular, orientation-selective, ON and OFF responses to the bar of light, no distinct ON and OFF regions

Answer 60

Complex cells

Question 61

Each module capable of analyzing every aspect of a portion of the visual field

Answer 61

cortical modules

Question 62

beyond the striate cortex: Analysis of visual motion and the visual control of action

Answer 62

dorsal stream

Question 63

beyond the striate cortex: Perception of the visual world and the recognition of objects

Answer 63

ventral stream

Question 64

localized below the temporal lobe; highly activated when we see a face and try to recognize it

Answer 64

fusiform face area (FFA)

Question 65

neurological disorder characterized by the inability to recognize faces.

Answer 65

prosopagnosia