vision 3 Flashcards
describe the extrastriate blob pathway
blob (layer 2/3), thin stripes in V2, V4
describe the interblob extrastriate pathway
interblob (4c Beta), thick stripes in V2, V3 and V4
describe the magnocellular extrastriate pathway
4B, thick stripes (V2), V3 and V5
what information do the thick stripes relay
movement, orientation, display
what information do the thin stripes relay
wavelength
V3
form, highest concentration of orientation selective cells
V4
color, non wavelength sensitive color, form in association with color,
achromatopsia
when you cant see color because you are missing the proper cortical space to perceive it
V4 IT (inferotemporal cortex)
colors, shapes, faces, facial recognition, visual perception overall, visual memory
V5
middle temporal lobe, retinotopically organized, motion, lesion gives you “snapshot” memory
MST
figure out what this stands for, relates to linear, radial, and circular motions, navigation, eye movement
types of visual perception
color, shape, size, form
color constancy
the light reflected by an object will adjust according to the light it is illuminated with so that you will always
lightness constancy
the light reflected by a dark vs. light object will remain proportional depending on the light illuminated on it
VA of an object is a measure of the size
of the object’s image on the__________
retina
what cues enable us to properly assess depth perception
relative size, interposition, linear perspective, aerial perspective, light and shade
what is cataracts and what causes it
opacity which develops in the lens of the eye, possibly due to congenital reasons, most common reason for blindness in the world
what is retinitis pigmentosa and what causes it
RP is a genetic abnormality which is from a lack of rods and therefore also a loss of cones, defective dark adaptation/night blindness, then a constriction of the visual field, finally total blindness
-autosomal dominant
What is the Argus 2 retinal implant
The Argus 2 retinal implant is a treatment for RP which recreates the image of a visual stimulus on a digitized retina and then stimulates the optic nerve
macular degeneration
-less severe dry MD and wet MD, deposits of debris and dead tissue coagulate on the retina causing gradual vision loss
-more severe wet MD causes new growth of blood vessels beneath the retina creating blind spots on vision
-age, smoking, family history
how does Anti-VEGF help with macular degeneration
-this therapy blocks the growth of new abnormal blood vessels through injections
-vascular epithelial growth factor
glaucoma
occurs as the result of elevated intraocular pressure when the aqueous humor does not have proper drainage from meshwork and too much is produced by the ciliary body
ventral stream
goes from occipital lobe towards the temporal lobe, involves object recognition, dominated by parvo and koniocellular pathways
dorsal stream
goes from occipital lobe towards parietal lobe, involves motion perception, dominated by magnocellular pathway
