Abstract
To probe central representations of colour we used a reverse Stroop task. Observers were instructed to ignore the colour in which a colour-word was presented (the distractor colour) and to respond to the meaning of the colour-word (the target). Stroop tasks typically produce faster reaction times (RTs) for congruent combinations, when distractor and target match, than for incongruent combinations, when they do not match. We used the basic colour terms identified by Berlin & Kay (1969) as targets, with distractor colours that were evenly sampled from a perceptually uniform colour space. We argue that RT differences in the reverse Stroop task can be used to quantify the mapping between cone-excitation space and a “cognitive colour space” defined at an advanced level of neural processing. Such cognitive colour maps reveal regions of excitation and inhibition for each colour term and distortions imposed by different chromatic contexts.
We then obtained cognitive colour maps in three conditions: (a) Bilingual Chinese students using their native language; (b) Bilingual Chinese students using their second language; and (c) English students using their native language. The maps differed significantly for Chinese students working in their native language compared to their second language (a vs b), and for English and Chinese students working in English (b vs c). However, the maps were not significantly different for Chinese students working in their native language compared with English students working in their native language (a vs c). We tentatively conclude that the structure of the cognitive colour space we measure is independent of native language.