Classes 7 and 8 - Occipital lobe and vision disorders

Question 1

What are two sulci in the occipital lobe?

Answer 1

Parieto-occipital sulcus and calcarine sulcus

Question 2

What visual cortices are on the lingual gyrus?

Answer 2

V2 and primary visual cortex

Question 3

What visual cortices are on the fusiform gyrus?

Answer 3

V4

Question 4

What are different names for V1?

Answer 4

BA17, striate cortex, primary visual cortex

Question 5

What is the prestriate cortex?

Answer 5

V2

Question 6

What are V3, V4 and V5?

Answer 6

Extrastriate cortices

Question 7

What is the purpose of V4?

Answer 7

Perception of color

Question 8

What is a general pathway of the visual cortex?

Answer 8

LGN > primary cortex > secondary cortex > dorsal, ventral or STS stream

Question 9

What do the ventral, dorsal and STS streams do?

Answer 9

Identify the object, visual guidance of movements, visuospatial functions respectively

Question 10

What is the purpose of V5?

Answer 10

To detect motion

Question 11

What is the purpose of the STS?

Answer 11

To detect shape

Question 12

What are some hemisphere asymmetry features in the brain?

Answer 12

Right hemisphere is good for mental rotation. Left temporal-occipital region might be a part of image generation

Question 13

What is blindsight?

Answer 13

You are legally blind, but can still detect things in front of you to a certain extent

Question 14

What are the two visual pathways?

Answer 14

Geniculostriate (conscious vision) pathway and tectopulvinar (detecting and attending to visual stimuli) pathway

Question 15

What is monocular blindness and how does it happen?

Answer 15

Loss of vision in one eye. Caused by lesion to optic nerve or retina.

Question 16

What is bitemporal hemianopia and how does it happen?

Answer 16

Loss of vision in peripheral fields. Caused by lesion to optic chiasm

Question 17

What is nasal hemianopia and how does it happen?

Answer 17

Loss of vision in one nasal field. Caused by lesion to the lateral chiasm (outside tracts)

Question 18

What is homonymous hemianopia and how does it happen?

Answer 18

Blindness in one visual field. Caused by lesion in LGN, optic tract or V1

Question 19

What is macular sparing and how does it happen?

Answer 19

Sparing of the central visual field. Caused by lesion in the occipital lobe

Question 20

What is quadrantanopia and how does it happen?

Answer 20

Loss of vision in one quarter of the fovea. Caused by occipital lobe lesion

Question 21

What are scotomas and how do they happen?

Answer 21

Small blind spots. Caused by small lesions of the occipital lobe

Question 22

The loss of color vision is called what? Where is the lesion?

Answer 22

Achromotosia. Lesion in V4

Question 23

The loss of movement vision is called what? Where is the lesion?

Answer 23

Akineopsia. Lesion in V5

Question 24

What is the deficiency of being able to recognize objects called? Where is the lesion?

Answer 24

Visual object agnosia. Lesion in occipital temporal junction

Question 25

What is prosopagnosia? Where is the lesion?

Answer 25

Inability to recognize faces. Lesion in the fusiform face area

Question 26

What is visuospatial agnosia? Where is the damage?

Answer 26

Inability to position self to environment and identify position of objects with each other. Lesion in the parietal occipital junction

Question 27

What is optic ataxia? Where is the damage?

Answer 27

Loss of visual guidance of movement… cannot grab things. Lesion in dorsal stream.

Question 28

What are the two forms of simultagnosia? How do they work?

Answer 28

Ventral simultagnosia (can see multiple objects, recognition is piecemeal)
Dorsal simultagnosia (can only see one object at a time, objects in movement are harder to see)
Happens from bilateral parieto-occipital lesions

Question 29

What is Balint syndrome? How does it happen?

Answer 29

Optic ataxia, occulomotor apraxia, simultagnosia

Question 30

What is apperceptive agnosia? Where is the damage?

Answer 30

Inability to perceive the structure of objects. Bilateral damage to lateral parts of occipital lobes.

Question 31

What is associative agnosia? Where is the damage?

Answer 31

Can perceive/draw the object but cannot identify them. Results from anterior temporal lobe damage.