March 20 :
1) Color Blindness
a) Inability to perceive colors that an unaffected person can see
b) Color blind: perceive about 100,000 colors
i) Lack cone pigment due to bad X gene (one pigment is missing and cones are filled)
(1) Red/green: sex linked disorder, bad gene on chromosome, effects mostly men
ii) Dichromatic: two different cones, two pigments that will see colors
iii) Trichromat: three different cones, three pigments that will see colors (majority of us
are this)
c) Some people lack two types of cones (only one cone pigment); very rare; people that
live a life in grey scale and have other issues as well
i) Monochromatic; also known as achromatopsia (no colors)
d) Dichromats
i) Protanopia: red- green colorblind, know someone that has this and is normally a
male
(1) Example: Picture of red berries on the left with green leaves and picture on right
that shows green berries and green leaves
(2) 1% men
(3) 0.02% women (very small percent)
(4) No L pigment (red)
(5) Sex linked
ii) Deuteranopia: similar effects as protanope
(1) 1% of men
(2) 0.01% women
(3) No M pigment (green)
(4) Sex linked
iii) Tritanopia: blue-yellow (very rare)
(1) 7 gene mutation
(2) No S (blue cone pigment)
e) Why do these first two have similar spectral sensitivities?
i) Tremendous overlap of M and L compared to S cones (red and green cones overlap
almost completely, ratio helps what you are allowed to see) (S cone is all by itself
and we do not see blue, although you can’t see it as well as red and greens)
f) Monochromats
i) 1 in 30,000
ii) Only one cone type (S cones)
iii) “Blue cone monochromacy”
iv) Virtually no real color perception
v) Most monochromats have no cones at all
vi) Is packed with rods (monochromat)
, vii) Vision with a rod does not work, eyes are sensitive to light and do not work often
(1) Most common form of monochromacy: Rod Monochromat
g) Some birds have 4 cones:
i) Zebra finch as tetrachromat ( spread out nicely, cone is just for ultraviolet spectrum,
all of the cones are sensitive and can perceive ultra violet for zebra finch (we cannot
see it at all)
h) What about dogs and cats?
i) Dichromats! Plus dogs and cats
(1) Dogs: Blue cone and yellow cone, in the phobia have rods (cats too); they do not
work as well, dogs have 20/70 vision
(2) Cats: about the same, third cone, limitations, both have rods, and have another
structure called the Tupian (in the back of the eye, mirror in the back of the
retina that reflects the light and gives a chance to see the light, effect the ability
to see)
i) Mantis Shrimp have like 12 cones (duodechromats)
j) Glasses that “cure” dichromacy
i) $389.00
ii) Glasses can help bring out red and greens, have to have the ability to see red and
green, true dichromat does nothing for them, 20% of the glasses seem to work
2) Visual Processing in Cortex
a) Feature detectors
i) Neurons beyond retina respond to specific features
ii) V1 and V2: Primary cortex
iii) Latch onto one neuron and sticks, measures what the neuron is responding to,
certain angle and width for it to respond
iv) In V1 (striate cortex) and V2 (primary visual)
(1) Shape, rectangle
(2) Angle
(3) Spatial frequency: width of the shape
(a) Discovered in the 1950s
3) Mechanisms of Processing in the Visual
a) Vision science and child psychology:
i) Video: babies can show how brain developments, cannot talk but still able to
understand, cube when there is a white background, looks like there is a surface
March 22nd, 2023
Black and White Dress
1) Color Blindness
a) Inability to perceive colors that an unaffected person can see
b) Color blind: perceive about 100,000 colors
i) Lack cone pigment due to bad X gene (one pigment is missing and cones are filled)
(1) Red/green: sex linked disorder, bad gene on chromosome, effects mostly men
ii) Dichromatic: two different cones, two pigments that will see colors
iii) Trichromat: three different cones, three pigments that will see colors (majority of us
are this)
c) Some people lack two types of cones (only one cone pigment); very rare; people that
live a life in grey scale and have other issues as well
i) Monochromatic; also known as achromatopsia (no colors)
d) Dichromats
i) Protanopia: red- green colorblind, know someone that has this and is normally a
male
(1) Example: Picture of red berries on the left with green leaves and picture on right
that shows green berries and green leaves
(2) 1% men
(3) 0.02% women (very small percent)
(4) No L pigment (red)
(5) Sex linked
ii) Deuteranopia: similar effects as protanope
(1) 1% of men
(2) 0.01% women
(3) No M pigment (green)
(4) Sex linked
iii) Tritanopia: blue-yellow (very rare)
(1) 7 gene mutation
(2) No S (blue cone pigment)
e) Why do these first two have similar spectral sensitivities?
i) Tremendous overlap of M and L compared to S cones (red and green cones overlap
almost completely, ratio helps what you are allowed to see) (S cone is all by itself
and we do not see blue, although you can’t see it as well as red and greens)
f) Monochromats
i) 1 in 30,000
ii) Only one cone type (S cones)
iii) “Blue cone monochromacy”
iv) Virtually no real color perception
v) Most monochromats have no cones at all
vi) Is packed with rods (monochromat)
, vii) Vision with a rod does not work, eyes are sensitive to light and do not work often
(1) Most common form of monochromacy: Rod Monochromat
g) Some birds have 4 cones:
i) Zebra finch as tetrachromat ( spread out nicely, cone is just for ultraviolet spectrum,
all of the cones are sensitive and can perceive ultra violet for zebra finch (we cannot
see it at all)
h) What about dogs and cats?
i) Dichromats! Plus dogs and cats
(1) Dogs: Blue cone and yellow cone, in the phobia have rods (cats too); they do not
work as well, dogs have 20/70 vision
(2) Cats: about the same, third cone, limitations, both have rods, and have another
structure called the Tupian (in the back of the eye, mirror in the back of the
retina that reflects the light and gives a chance to see the light, effect the ability
to see)
i) Mantis Shrimp have like 12 cones (duodechromats)
j) Glasses that “cure” dichromacy
i) $389.00
ii) Glasses can help bring out red and greens, have to have the ability to see red and
green, true dichromat does nothing for them, 20% of the glasses seem to work
2) Visual Processing in Cortex
a) Feature detectors
i) Neurons beyond retina respond to specific features
ii) V1 and V2: Primary cortex
iii) Latch onto one neuron and sticks, measures what the neuron is responding to,
certain angle and width for it to respond
iv) In V1 (striate cortex) and V2 (primary visual)
(1) Shape, rectangle
(2) Angle
(3) Spatial frequency: width of the shape
(a) Discovered in the 1950s
3) Mechanisms of Processing in the Visual
a) Vision science and child psychology:
i) Video: babies can show how brain developments, cannot talk but still able to
understand, cube when there is a white background, looks like there is a surface
March 22nd, 2023
Black and White Dress
