Higher Visual Processing Flashcards
M and P pathways encode for? where do they terminate in V1?
M- motion 4C-alpha
P - colour 4C-beta
outputs of V1 layers?
3 = other cortical 5 = sup. colliculus/pons 6 = LGN
M ganglions project to which layer of LGN?
magnocellular layer
when does mixing occur with M ganglions?
AFTER entering primary visual cortex
What happens in Layer IVB of V1?
get directional selectivity
how much of cortex involved with visions?
40%
what are the 2 large cortical streams of visual processing?
M-cells: dorsal pathway
P-cells: ventral pathway
dorsal pathway detects?
where in visual field
Where do you get directional selectivity?
Layer IV-B in V1
ventral pathway detects?
what in visual field
Middle temporal lobe is for?
specialized for precessing object motion
Middle temporal lobe receives from 3 big places?
V2, V3, Layer IV-B of V1
almost all Cells in the Middle temporal lobe are?
directional selective to movement
3 kinds of cones are? maximal absorption at?
Red: 560
Green: 530
Blue: 430
How does colour vision work? 2 steps:
- detect relative amounts of cones working
2. comparison to each other
Red opposed by?
Green
Blue opposed by?
Yellow
P ganglions exhibit what kind of detection?
colour opponent centre surround
colour opponent centre surround means?
excited by red on centre
inhibited by green on surround
brain likes what kind of stimulation for light detection?
either maximal stim
maximal inhibition
Area V4 is important for perception of?
shape
colour
Area inferior temporal is a major output of?
V4
What does Area inferior temporal perception of?
faces
colour deficiencies happen how? 2 ways
inherited
acquired
male vs. female colour deficiencies?
8% males
0.5% females
What is: Monochromacy, Dichromacy, Anomalous trichromacy?
Monochromacy: only have one type of cone
Dichromacy: two functioning cones
Anomalous trichromacy: have 3 cones, one expresses abnormal pigment
Which is most common? Monochromacy, Dichromacy, Anomalous trichromacy?
Anomalous trichromacy
What is Tritan?
No blue cone
What is protan?
No red cone
What is Deutan?
No green cone
Which cone is deficient most commonly?
Green (Deutan)
Deutanopes with traffic lights: trouble how?
confuse red and yellow
protanopes with traffic lights: trouble how?
can’t see red easily
What kind of pathways carry visual info from retina to cortex?
parallel
neurons in V1 M pathways are two things:
- directionally selective
2. dorsal for motion
P pathways encode? 2 big ones. Which pathway?
colour and resolution (NOT MOTION)
ventral pathway
