Vision III Flashcards
(25 cards)
Fibers connect the lateral geniculate nucleus to the superior retinal quadrants. What information do they carry?
Lower half of visual field
Fibers connect the lateral geniculate nucleus to the inferior retinal quadrants. What information do they carry?
Upper half of visual field
Describe the flow of information into the primary visual cortex
Inputs to layer 4, projections to layers 2 & 3
Describe the flow of information out of the primary visual cortex (which layers?)
Outputs from layers 2,3,4,5,6
Projections from the primary visual cortex (V1) also go to visual associaton areas. These areas are associated with what information?
depth perception, motion detection, color vision
Which retinal ganglion cells cross at the optic chasm?
Nasal portion of the retina–lateral fields of vision
What protein is present at the temporal retina that is important in guiding neurons during development?
EphB1
Which protein is present at the optic chiasm and prevents certain axons from decussating while allowing others to cross?
Ephrin B2
What proteins are present after the optic chiasm that prevent recrossing of axons
EphB1 + EphrinB2
Where do the ganglion cells of the eye synapse?
In the lateral geniculate nucleus
What do simple cortical cells sense?
A bar of light
What do complex cortical cells sense?
Movement of light in a particular direction, corners or edges
How are neurons in the primary visual cortex organized?
Certain stimulus orientation patterns (think bar of light) are recognized. Similar recognition patterns are found in a verticle column
How is input from the two eyes organized?
Ocular dominance columns
How are ocular dominance columns (predisposition of areas to respond to only one eye) develop in the visual cortex?
After initial guidance by Ephs and Ephrins, the dendrites are “pruned” in a L-R-L-R pattern
What is necessary for normal development of ocular dominance columns?
Visual input from both eyes from an early age
Strabismus
misalignment of eye
Amblyopia
Lazy eye
The dorsal pathway of visual information in the cortex conveys what information?
Motion, depth perception, relative size
The ventral pathway carries what visual information?
object/form recognition
What is akinetopsia?
Motion blindness
Stereopsis
Perception of depth from two slightly different images in each eye
What is the binding problem?
Question of how the brain selectively puts together the correct data in a specific way rather than some other inappropriate combination?
What is motion parallax?
Closer things move faster on the retina when we turn our head
