Sight Flashcards
Fovea
Inside of the macula which is in the retina. Highly dense with cones. Sees rich detail
Macula
Inside retina, small section within is the fovea
Neural sensation
Photoreceptor—> light
Retinal cells
Concert light into neural impulse
Rods: very sensitive. In periphery of retina. See at night
Cones: red, green, blue cones. Color specific. Fovea. Fine details.
Phototransduction cascade
Rod activates bipolar cell, then. Retinal ganglion, optic nerve, brain.
Rhodopsin
Portion of rods (retina).
RETINAL: molecule in rhodopsin that changes shape with light
TRANSDUCENT: molecule that breaks away from rhodopsin (following retinal), activates cascade, turns off rod, activates bipolar cell
Rods
Optic disks: proteins that absorb light
More sensitive to light than cones!
Slow recovery time
Cones
Optic disks
Photopsin (equivalent of rhodopsin)
Quick recovery time
Red, blue, green
Ratio of cones to rods in retina
Cones: 6 million
Rods:120 million
Rods»cones
Optic chiasm
Where the optics nerves from each eye merge
Visual fields
Left visual field–>right side of brain
Right visual field–> left side of brain
Feature detection
Color: Cones
Form: parvo pathway– spatial resolution, bad temporal (motion) resolution, color
Motion: magno pathway– high temporal (motion) resolution, no color
Trichromatic theory
Cones:
60% red
30% green
10% blue
Parallel processing
Seeing motion, form, and color simultaneously.
