Colour Perception Flashcards
colour vision helps with
foraging and mate selection (we see redder faces as more attractive)
pathway of colour information
1) cones
2) bipolarcellss
3) ganglion
4) LGN
5) V1
primary colours
red
green
blue
subtractive colour mixing
pigments, dyes, paints
the colour not absorbed it was what we see
all colours = brown
additive colour mixing
coloured lights
light adds its most dominant wave length
all colours = white
trichromatic theory
- the retina contains 3 different kinds of receptors which are maximally responsive
- pros: a simple explanation
- cons: yellow, not explained
Opponent process theory
each colour receptor is made up of a pair of opponent processes
___ theories needed to explain colour processes
both
after images
when a colour is receptor is excited or inhibited for a long time you get a rebound effect when you look at a neutral stimulus
rebound effect
when look at neutral stimulus you see the complementary colour of the colour that you have stared at
center surround fashion
first (inside) excited
second (outside) inhibited
high resolution channels
1 cone to 1 ganglion
small receptive field
low resolution channels
mant comes to one ganglion
large receptive field
receptive field
area of the retina that will cause the ganglion to increase or decrease firing rate
LGN layer
magnocellular: movement and depth
parvocellular layers: colour and form
koniosublayers: blue ganglion > PVC
CO blobs
in V1
responfd tocolour info only
causes of colour blindness
heretitary
visual cortex injury
protonopia
no red cones
deuteranopia
no green cones
protanopia vs deuteranopia
see same things, only way to tell difference is to look at the cones
tritanopia
cant percieve blues and yellows
rare
achromatopsia
see world in grey shades
tetrachromat
have 4 colour recptors
wave lengths
red: long
Purple: short
