Perception II

Question 1

Trichromacy & Opponent Processing - 3 main types of colour cones

Answer 1

S Cones absorb 420 nm
M Cones absorb 534 nm
L Cones absorb 564 nmL

Question 2

adaption

Answer 2

Neuronal fatigue

Adaptation is adaptive ((Clifford & Rhodes, 2005
Dynamic adaptation reduces the need for constant firing

Adaptation acts as a comparison to previously seen images

Question 3

Colour constancy

Answer 3

No simple relationship between wavelength colour perceived

Objects colour is reflected light from source light
This source differs, yet colours remain perceived the same (Land, 1977)

Question 4

Colour constancy - ways of assessing

Answer 4

Methods of assessing (Foster, 2003):

Colour-patch naming (e.g., Land, 1977)
But too many labels to choose from

Colour-patch rating (e.g., Speigle, 1997
Difficult to analyse

Colour-patch matching (e.g., Land, 1977)
Must be careful about instructions

Achromatic adjustments
Judging differences to whiteJ

Question 5

Categorical perception

Answer 5

Colour naming task (Harnad, 1987)
.Cross-category discriminations easy

Within-category discriminations difficult

Hues reliably named one colour not another

Certain hues never confused

Question 6

The interplay of language

- Linguistic relativity

Answer 6

If we do not have a word for something, we cannot perceive its
Warping of internal colour space (Davidoff, 1991)
Universals of (colour) perception

We are genetically pre-programmed to perceive certain colours (Heider, 1970)

Based on trichromacy

Question 7

Universal Perception

Answer 7

Categorical perception (CP) in other language

Berinmo Speakers (Kay & Regier, 2007)

Russian/Welsh (Berlin & Kay, 1972
Colour perception in pre-stone peoples (Rosch-Heider,1972)

Colour discrimination in infants (Teller & Bornstein, 1987)

Colour memory unaffected by names (Heider & Oliver, 1972)
Also exists for emotions

Question 8

Universal Perception - criticism

Answer 8

Much of the research is flawed (Lucy, 1997)

Linguistic understanding of languages not same as common usage

The performance of participants is often very poor

If analyzed using multidimensional scaling,universals do not occur
The results are not always replicated

Question 9

Linguistic Relativity

Answer 9

Colour perception & CP other languages, when response bias is controlled ((Roberson, Davies, & Davidoff, 2000)

Disruption of Categorical Perception through verbal interference ( (Roberson & Davidoff, 2000) Discrimination of colours even without names ( (Bornstein, 1975

Infants cannot discriminate all colours (Adams et al., 1991)

Question 10

Universals vs Relativity

Answer 10

Do different languages have different categorical boundaries in perception?
Does this affect memory

 What would happen if the colour boundary was shades?
Colour constancy as evidence

Maybe a weak linguistic relativity hypothesis is most parsimonious