ch 13 occipital lobe

Question 1

anatomy

Answer 1

no clear subdivisions on lateral surface
medial surface-parietooccipital surface, calcarine sulcus (has primary visual cortex, separates upper and lower visual fields)
ventral surface-lingual gyrus (V2&VP), fusiform gyrus (V4)

Question 2

color vision

Answer 2

V4, distributed throughout

detects movement, depth, and position (shadows)

Question 3

primary visual cortex (V1) connections

Answer 3

input of lateral geniculate nucleus of thalamus, output to all other levels

Question 4

secondary visual cortex (V2) connections

Answer 4

output to all other levels

Question 5

connections after V2

Answer 5

output to parietal lobe-dorsal (where) stream
output to inferior temporal lobe-ventral (what) stream
output to superior temporal sulcus (STS)

Question 6

visual pathways-dorsal stream

Answer 6

visual guidance of movements

Question 7

visual pathways-ventral stream

Answer 7

object perception

Question 8

visual pathways-STS

Answer 8

visuospatial functions and perception of certain movements

Question 9

theory of function

Answer 9

vision begins in V1 and travels to more specialized zones, selective lesions up hierarchy produce specific deficits, lesions to V1 not aware of seeing

Question 10

vision for action

Answer 10

see in order to act, parietal visual areas in dorsal stream (reach, duck, catch)

Question 11

action for vision

Answer 11

move to see it all, visual scanning-move eyes and selective attention, saccades and pursuit problems

Question 12

visual recognition

Answer 12

temporal lobes, object recognition

Question 13

visual space

Answer 13

knowing where you are in space, parietal and temporal lobes, spatial location-egocentric (relation to self) and allocentric (relation to other objects)

Question 14

visual attention

Answer 14

selective attention for specific visual input, parietal lobes guide movements and temporal lobes help in object recognition

Question 15

dorsal stream is set of systems for online visual control of action

Answer 15

know because visual neurons in parietal corext only active when brain acts on visual info

Question 16

STS stream characterized by

Answer 16

polysensory neurons, neurons responsive to both auditory and visual input or both visual and somatosensory input
originates from structures in parietal and temporal cortex

Question 17

monocular blindness

Answer 17

destroy retina, optic nerve at bundles, loss of sight in 1 eye

Question 18

bitemporal hemianopia

Answer 18

loss of vision from both temporal fields, lesion to optic chiasm, peripheral vision on both sides lost

Question 19

nasal hemianopia

Answer 19

loss of vision to 1 nasal field, lesion of lateral chiasm

Question 20

homonymous hemianopia

Answer 20

blindness of entire visual field, results from complete cut of optic tract, lateral geniculate body, or area V1

Question 21

macular sparing

Answer 21

sparing of central or macular region of visual field, lesion to occipital lobe

Question 22

hemianopia, quadrantoanopia

Answer 22

complete loss of vision in 1/2 or 1/4 of fovea, lesion to occipital lobe

Question 23

scotoma

Answer 23

field defects, small blind spots, small occipital lobe lesions

Question 24

conclusions to be made from case studies

Answer 24

distinct syndromes of visual disturbance, some provide evidence for fundamental dissociation between dorsal and ventral streams, visual experience not unified, asymmetry in functions

Question 25

apperceptive agnosia

Answer 25

type of object agnosia, inability to perceive structure of objects
simultagnosia-inability to see multiple objects at a time
bilateral damage to lateral occipital lobe

Question 26

associative agnosia

Answer 26

object agnosia, perceive objects but not identify them, anterior temporal lobe lesions

Question 27

prosopagnosia

Answer 27

can’t recognize faces, facial features or expressions, or tell human from nonhuman face

Question 28

alexia, dyslexia

Answer 28

cant read, form of object agnosia-can’t construct wholes from parts, form of associative agnosia-word memory damaged/inaccessible, damage to left fusiform and lingual areas

Question 29

visual imagery

Answer 29

neural structures mediate perception and visualization not completely independent, R hemisphere usually does mental rotation, L hemisphere for image generation

Question 30

V1 features

Answer 30

complex laminar organization, appears anatomically homogeneous but can be heterogeneous when stained with cytochrome oxidase-blobs
lesions in V1 can still get to V2, but must function so brain can make sense of whats happening

Question 31

V2 features

Answer 31

can also be hererogeneous when stained with cytochrome oxidase, reveals stripes

Question 32

3 pathways from V1&V2

Answer 32

v1->v4-color aread
v1->v2->v5-middle temporal, motion
v1&v2->v3-shape of objects in motion, form perception

Question 33

V1 to temp lobe in ventral stream

Answer 33

knowing what an object is

Question 34

V1 to pari lobe in dorsal stream

Answer 34

controlling visual guidance of movements

Question 35

visual field organization

Answer 35

left half of each retina sends projections to R brain, R half of each retina sends projections to L brain

Question 36

infarct

Answer 36

dead tissue

Question 37

angioma

Answer 37

collection of abnormal blood vessels

Question 38

optic ataxia

Answer 38

deficit in visually guided hand movements

Question 39

prosopagnosia

Answer 39

facial recognition deficits

Question 40

visuospatial agnosia

Answer 40

can’t find way around, spatial perception/orientation