Chapter 9 Flashcards
What is cerebral achromatopsia?
Colour blindness caused by a cortical injury
How does most colour deficiency occur?
At birth because of genetic absence of one or more types of cone receptors
What did Thortstenson find?
That colour can be a cue to emotions signaled by facial expressions
What wavelengths appear violet?
400 to 450 nm
What wavelengths appear blue?
450 to 490 nm
What wavelengths appear green?
500 to 575 nm
What wavelengths appear yellow?
575 to 590 nm
What wavelengths appear orange?
590 to 620 nm
What wavelengths appear red?
620 to 700 nm
What are chromatic colours?
Blues, greens, reds
Occur when some wavelengths are reflected more than others
What is selective reflection?
When some wavelengths are reflected more than others
What are achromatic colours?
Whites, grays, blacks
Occur when light is reflected equally across the spectrum
What is a reflectance curve?
Plots the percentage of light reflected form objects in the visible spectrum
What is selective transmission?
In terms of things that are transparent, only some wavelengths pass through the object or substance
What are transmission curves?
Plots of the percentage of light transmitted at each wavelength
They look similar to reflectance curves but with percent transmission plotted on the vertical axis
What happens when two paints are mixed?
Both paints still absorb the same wavelengths they absorbed when alone, so the only wavelengths reflected are those that are reflected by both paints in common
What are nonspectral colours?
Those that do not appear in the spectrum because they are mixtures of other colours
What happens when hues because desaturated?
They can take on a faded or washed-out appearance
What did Newton argue about the colour spectrum?
That each component of the colour spectrum must stimulate the retina differently in order for us to perceive colour
What is the trichromacy of colour vision?
Colour vision depends on the activity of three different receptor mechanisms
What is the colour matching experiment?
The participant is shown a reference colour that is created by shining a single wavelength of light on a reference field
The participant then matches the reference colour by mixing different wavelengths of light in a comparison field
What are the findings from the colour matching experiment?
Any reference colour could be matched provided that observers were able to adjust the proportions of 3 wavelengths in the comparison field