lecture 4 - colour vision Flashcards
what are detection and discrimination based on?
colour
why is colour important?
can see if someone is ill, can see if something is cooked or not
how many colours are there in the world?
Continuum - colours and shades - secondary colours
how does colour vision work?
constructed by our visual system (depends on the eye of the beholder)
what are the nuts and bolts of trichromacy?
Retina at back of the eye
Many cells forming the network of the eye
3 types of rods and cones
what is trichromacy?
Short wavelength (Blue cones), medium wavelength (green cones), long wavelength (red cones)
what is the YOUNG-HELMHOLTZ theory of trichromacy?
Observers were asked to adjust the relative amounts in a mixture of several wavelengths (i.e. a comparison stimulus) until it matched the colour of a single wavelength in a test stimulus
what is the principle of univarian?
Observers were asked to adjust the relative amounts in a mixture of several wavelengths (i.e. a comparison stimulus) until it matched the colour of a single wavelength in a test stimulus
how do we colour match?
2 types of cones
what are cone variations?
dichromats
what is protanopia?
no l cones
what is deuteranopia?
no m cones
what is tritanopia?
no s cones
what is a monochromat?
cant see any colour but can see diffs in intensity and pick up certain wavelengths
what is colour opponency?
Artists use a colour circle to know what to mix with what to achieve colour they want
Unique hues - Red, green, yellow, blue - only unique in how you see them
