Please enable JavaScript.
Coggle requires JavaScript to display documents.
Vision (Perception of Color (perception, what wavelengths hit the retina
…
Vision
Perception of Color
- perception, what wavelengths hit the retina
-aka wavelengths reflected by medium
- bright red reflects 560 nm (G) and absorbing other wavelengths
Color Mixing
- LIGHT: Additive
- Paint: Subtractive
-additional pigments reflect fewer wavelengths
-blue+yellow= green
-
Eye Anatomy
(outer most) Cornea: transparent outer layer at the front of the eye
Iris: the colored part, pigmented ring of muscles behind the cornea
Pupil: opening in Iris; regulates amount of light
Lens: transparent onion-like layers that changes shape to focus the incoming light on the retina
Vitreous humor: clear gelatinous substance inside
Retina: contains photoreceptors
Photoreceptors: located in retina; transduce light into E particles
-Rods:
-Cones:
- Fovea: central region of the retina
-ONLY CONES; detail vision (acute)
- Optic disk: location of the exit point from the retina for the fibers of the ganglion cells that form the optic nerve
-"blindspot"
Retina in Detail
Retina = Neural Tissue
- Layered & contains 3 main types of cells
1.) Photoreceptors
2.) Bipolar cells
------ Photoreceptors form synapses with them and they in turn synapse on the ganglion cells
3.) Retinal ganglion cells
- -----Axons = optic nerve that travels back to the brain
-
Cell Modulate Activity
- Horizontal Cells: Transmit information in a parallel direction; combines information from adjacent photoreceptors
- Amacrine Cells: Transmit information in a parallel direction; combines information from adjacent bipolar & ganglion cells
-
-
Trichromatic Theory: Young: R,B,Y = any color!
- cones
- red cones: 560 nm
- green cones 530 nm
- blue cones: 420 nm
-# red = # green; >>> # blue
Opponent Process Theory: Henry: we can see reddish orange, but not reddish blue: not everything mixes/blends
-
-
- Topographical mapping (retinotopic map)
- Cortical magnification: Dramatic scaling of info from diffparts of visual field
-large cortical representation of fovea>>>> periphery
-
V1/Striate -> V2/Extrastriate
- V5: perception of visual motion
- V2, V4, & Temporal (IT) = perception of form
-act by complex shapes, ex: faces
- V4: color constancy
- V8: color discrimination
-Achromatopsia (vision without color)