Opponency Circuitry (M2) Flashcards
What is different about the S-cone circuitry?
primary bipolar cell for S-cones does not contact L- and M-cones
What is the role of color opponency?
aids in ability to clearly differentiate between different hues
What is the process of negative after-images?
- stare at red light for long period so adaptation in channel mediating red stimulation
- when look at white all pathways stimulated but less in red pathway because of adaptation and more in green so see green
Where is unique blue located? 1. Unique green? 2. Unique yellow? 3. Unique red? 4
- 465nm; crossing point of red to green
- 500nm; crossing point of blue to yellow
- 580nm; crossing point of green to red
- non-spectral
What types of opponency do small bi-stratified RGCs show? 1. Where are their spectral peaks? 2. What do they signal for? 3
- chromatic
- 440 and 555nm
- blue-yellow color
During the Hue Cancellation Experiment what color did the observer have to add to get rid of the redness when the light looks violet? 1. To get rid of the blueness? 2
- green
2. yellow
What is the Young-Helmholtz trichromatic theory? 1. What cannot be explained by this theory? 2
- there are three distinct receptors in the retina that make color vision possible
- certain color combinations don’t mix in perception and the presence of negative after-images
During the Hue Cancellation Experiment what color did the observer have to add to get rid of the redness when the light looks orange? 1. To get rid of the yellowness? 2
- green
2. blue
What is the difference between midget RGCs and parasol RGCs in terms of center surround?
- midget RGCs display color opponeny
2. parasol RGCs have the center win with either diffuse red or green light so show no color opponency
What are the wavelengths that do not change in hue with differing brightness?
- 470nm
- 503nm
- 578nm
What are the roles of midget bipolar cells?
- mediate high-acuity vision
2. mediate re/green color vision unique to trichromats
What are the three opponent color vision channels?
- red-green channel
- blue-yellow channel
- black-white channel
For wavelengths that are less than unique green, what color do the stimuli appear an intensity increases?
blue
What are the zones in the zone model of color vision?
- zone 1 is 3 receptors (3 cones)
2. zone 2 is post-receptoral (output from receptors combined into different opponent and non-opponent channels)
What types of opponency do midget RGCs show? 1. Where are their spectral peaks? 2. What do they signal for? 3
- spatial and chromatic
- 520 and 600nm
- pattern info and red-green color
What type of bipolar cell is involved in the S-cone circuitry? 1. Where does it synapse? 2. What does it synapse with? 3
- ON-type
- ON sublamina of the IPL
- small bi-stratified RGC
What are hues that contain no trace of any other hue?
unique hues
What color after-image is made by a red image? 1. Blue image? 2. Black image? 3
- green
- yellow
- white
What is maximum resolution acuity dependent on in the structure in the retina?
- cone spacing
2. midget pathway (high spatial resolution in fovea)
What feeds into the small bi-stratified RGC that is in the S-cone circuitry? 1. What is the result of this? 2
- diffuse OFF bipolar that receives input mostly from L- and M-cones
- these RGCs have a blu-light ON response and a yellow (green+red) OFF response so color antagonism
For wavelengths that are greater than unique green, what color do the stimuli appear an intensity increases?
yellow
What is the chromatic content of a stimulus that is the property associated with its dominant wavelength? 1. Is it dependent on light intensity? 2
- hue
2. yes
What types of opponency do parasol RGCs show? 1. Where are their spectral peaks? 2.
- spatial
2. 555nm
