Study Guides (238,524)
Canada (115,195)
Psychology (1,813)
PSYB51H3 (53)

PSYB51 lecture 5 notes for midterm 2

3 Pages
Unlock Document

University of Toronto Scarborough
Matthias Neimier

PSYB51 LECTURE 5: the perception of colour Colour: not a physical property, it is made up by the brain. Green filter: nose and stars appear equally bright but are actually a very different colour. Problem of univariance: an infinite set of different wavelength-intensity combinations can elicit exactly the same response from a single type of photoreceptor. It’s better to talk about S M and L cones rather than red, green and yellow cones Scotopic: referring to dim light levels at or below the level of bright moonlight. - rods are sensitive to scotopic light levels - All rods contain same type of photopigment molecule: Rhodopsin Newton: prisms break up sunlight into spectral components Young-Helmholtz (-Maxwell) theory: trichromatic colour vision. Colour vision is based on 3 photoreceptors sensitive to particular ranges of wavelengths. *Maxwell’s colour matching techniques Metamers: any pair of stimuli that are perceived as identical in spite of physical differences. In terms of light: different mixtures of wavelengths that look identical. Additive colour mixture: a mixture of lights. If light A and light B are both reflected from a surface to the eye, in the perception of colour, the effects of those two lights add together. This is what happens when mixing light with different colours. Subtractive colour mixture: a mixture of pigments A and B mix, some of the light shining on the surface will be subtracted by A and some by B. only the remainder contributes to the perception of colour. Non-spectral hues: hues that don’t exist as pure forms of light but only as mixtures of different wavelengths. Opponent colour theory: the theory that perception of colour is based on the output of three mechanisms, each of them on an opponency between two colours: red-green, blue-yellow, and black-white. Afterimage: a visual image seen after the stimulus as been removed. LGN (lateral geniculate nucleus) has colour-opponent cells: neurons whose output is based on a difference between sets of cones. Achromatopsia: an inability to perceive colours that is due to damage to the central nervous system. Two types of colour blindness: - cone monochromat- have only one cone in their retina - rod monochromat- no cones of any type; truly colorblind
More Less

Related notes for PSYB51H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.