Central Visual Processing I Lec12 Flashcards
The retina ganglion cells have 3 pathways:
magno, parvo, k pathway
Visual fields are ___ and ___ in the retina.
flipped and inverted
in the optic chiasm, ___ axons cross
nasal axons (temporal visual field)
nasal axons carry information from the
temporal visual field
![](https://s3.amazonaws.com/brainscape-prod/system/cm/080/599/058/a_image_thumb.png?1659418828)
in the optic chiasm ___ axons stay ipsilateral
temporal
LGN has 6 layers
the 2 magnolayers are ___
ventral
LGN has 6 layers
the 4 parvo layers are ___
dorsal
in the lgn, the inputs are segregated by
eye
lgn gets feedback input from
V1’s layer 6
V1 is ordered ____
retinotopically
in v1, more cortical area is given to
central vision/fovea
order of M,P,K in V1
M, P, and K pathways mix substantially here
M pathway is still partially seperated to provide a fast motion processing
All V1 neurons have retinotopy which is a ___ field position
receptive
V1 neurons are that orientation tuned
interblobs
look at angle of a light bar –> edges
V1 neurons that are center/surround
blobs
The V1 functional unit is a ____
hypercolumn
Ocular dominance hypercolumn =___ and ___ columns
right eye column + left
eye column
![](https://s3.amazonaws.com/brainscape-prod/system/cm/080/599/541/a_image_thumb.png?1659418829)
A complete hypercolumn =
ocular dominance hypercolumn
+ orientation hypercolumn + color blobs
One hypercolumn contains all the cortical machinery to fully analyze one point in visual space for all ___ and ___
orientations and both eyes
![](https://s3.amazonaws.com/brainscape-prod/system/cm/080/599/562/a_image_thumb.png?1659418829)
Input from optic radiations goes to___ in V1
layer 4
Output of V1 going to V2 leaves from ___
layers 2&3
Output from V1 to superior colliculus leaves from
layer 5
Feedback from V1 back to LGN leaves from
layer 6
___ has large (1.5mm) stripes that stain with cytochrome oxidase
V2
Dorsal pathway to ____ visual cortex
parietal
Ventral pathway to ___ visual cortex
temporal
the where pathway is the
dorsal pathway
the what pathway is the
ventral pathway
the where pathway is involved with
motion and
object localization
the what/ventral pathway si involved with
pattern and object recognition.
As you go to higher cortical areas… ___ integrate, summate, and enlarge
Receptive fields
lesions in higher cortical areas (above v1) usually manifest as specific visual deficits like
loss of color vision or form vision
lesions in V1 manifest as__ or ___
blindness or scotomas
ganglion cells in the retinal detect what (4)
spatial representation (receptive fields & retinotopy)
• retinotopy - the mapping from the retina to initial neurons
- luminence / intensity (esp. rods)
- spectral absorption (cones, color)
- spatial contrast (center/surround, ON/OFF,
edges)
spatial contrast is related to
center surround receptive fields