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Vision Neuro
chapter 6
Question | Answer |
---|---|
sensory transduction | physical stimuli changed to electrochemical signal |
human vision | 350 to 700 nm |
cornea | outer protective structure |
iris | colored opening/ control the pupil |
pupil | opening in the iris that allows a certain amnt of light |
sclera | whites/protective layer |
vitreous humor | gelatinous inside of eye/proteins |
lens | controls where image is projected onto the retina |
retina | neural tissue/back of eye/sensory receptors |
optic nerve | axonal propagations toward the brain |
retina | photoreceptors/fovea/optic disk |
rods | low light/ abundant/cylindrical/periphery |
cones | high acuity/ daytime/ color/toward fovea |
fovea | focus/most acute/ all cones |
optic disk | where the optic nerve exits the eye/ blind spot |
amacrine cells | connect bipolar and ganglion |
bipolar cells | receptor to ganglion/1 bipolar per photorec |
horizontal cells | receptors and bipolar/adjust light |
ganglion cells | axon potentials generated/optic nerve |
photopigments | opsin/retinal |
light hits rhodopsin | rod opsin and retinal |
rod opsin changes color | change in membrane potential |
visual pathway | retina-optic nerve-optic chiasm-lgn of thalamus-primary visual cortex |
retino-geniculo-cortical pathway | broken down in thalamus-staysin ipso |
6 layers of primate LGN | sep depending on ipsi/contra |
layers 1 and 2 | magnocellular-larger |
layers 3-6 | more dorsal/parvocellular |
layers 1,4,6 | input is contralateral |
layers 2,3,5 | input ipsilateral |
center-surround cells | create a field of cells |
ganglion cells | project 1st ap |
hartline | frogs/some cells stim more with (out) light |
on-off cells | only when switch from light to no light and vice versa |
kuffle | on middle with off periphery(structure) |
schiller | rod cells= all on cells |
young's trichromatic | red/green/blue/3 types of receptors |
trichromatic coding | 3 diff wavelengths |
blue cone peak | 419 nm |
rod peak | 496 nm |
green cone | 531 nm |
red cone | 559 nm |
opponent-process coding | blue on, yellow off etc |
color vision deficits | dichromatics |
x-linked | protanopia/deuteranopia |
protanopia | see in yellow and blue/red cones have green opsin |
deuteranopia | see all 3 colors but green filled w red opsin |
tritanopia | blue cones absent/defective |
primary visual cortex | striate cortex |
pvc | 6 layers w sublayers |
projections from LGN | enter layer 4 |
processes info from | ganglion cells and LGN |
modular organization in V1 | blobs/inter-blobs/ocular dominance |
blobs | cytochrome oxidase/higher rates of met/color-opp process |
inter-blobs | orientation of objects/spatial/movement |
ocular dominance | receive info from same eye/ keep each eye separate |
vc l 1 | dendrites and axons of other layers |
vc l 2/3 | projection to temporal and parietal |
4 | receive input from LGN |
5/6 | project back to LGN |
hubel and wiesel | V1 line detectors |
simple | opponent process |
complex | movement of the line |
ungerlerder and mishkin | visual association cortex has 2 streams of processing |
dorsal stream | posterior parietal lobe/magno/where? |
ventral stream | inferior temporal lobe/m and p/ what? |
visual association area | analysis/higher order processing |
magnocellular | no color/high contrast/low spatial/quick |
parvocellular | color/low contrast/high spatial/slow |
visual association cortex functions | orientation/mvmt/spatial frequency/retinal disparity/color |
dorsal stream | location/spatial/terminates in posterior parietal cortex/balint's syndrome |
optic ataxia | diff reaching for an object |
ocular apraxia | visual scanning problems |
simultanagnosia | not more that 1 object at a time |
ventral stream | highest level of processing/form/3D |
higher-order processing | V4/ITC/PPC/V5 |
V4 | color |
ITC | face cells/complex objects |
PPC | spatial perception |
V5 | movement/info from superior colliculus/ |
achromatopsia | damage to medial occipital lobe/cant remember colors before damage |
pulvinar | region of thalamus that projects to V5/coordinates eye and hand mvmts |
fusiform face area | in fusiform gyrus/temporal lobe |
visual agnosia | deficits in perception w/o blindness |
apperceptive | cant perceive objects/ |
prosopagnosia | can't recognize faces |
associative visual agnosia | cant name objects |