08. LGNV1 Flashcards
What are the types of layers in the LGN? How many layers are there?
Layers 1 & 2 are MAGNO cellular layers
Layers 3-6 are PARVO cellular layers
Which type of cells belong in what layer?
Midget –> Parvo
Parasol –> Magno
(Ps and Ms are switched)
Activity in the LGN is dependent on what? (from the brain…)
Attention!
- this cannot happen in the retina bc the retina doesn’t receive any signals from the brain
What distinct information is maintained (separate) throughout the LGN?
- R or L side of visual field
- midget vs parasol cells
- Relative location/order of objects in visual field
–> triangle, square, star, etc
The PARVO layer is important to perceive what kinds of information?
- Color
- Food
The MAGNO layer is important to perceive what kinds of information?
- movement
- flicker
Does perception happen in the LGN?
No, its just a pathway
What does retinotopic mapping mean?
the point-by-point representation of the retinal surface in another structure in the visual system (ex. LGN, V1, etc)
What does retinotopic mapping tell us?
the location of neural activity provides information about the location of the stimulus (and the region of retina that’s being stimulated)
- IE –> we know spatial relationship
Cortical magnification def?
- More space in the brain is allotted to stuff that is close to the fovea
- magnifies the fovea
What kind of structure/organization is there in V1?
COLUMNAR organization
Ocular dominance columns means…?
- L/R eye signals are maintained/separated in V1 through columns
Orientation columns means…?
- cells with preferred orientations are organized in columns systematically
- cells in a column have the same orientation, adjacent columns are similar
- location of activity gives us info on the orientation of stimulus
Location columns means…?
- receptive fields on retina organized systematically in columns
- same column –> roughly same spot on retina
- adjacent columns –> close by / slightly diff
- loc. of neural act. tells us about loc. of stimulus
