title: Interactions between colour and synaesthetic colour: an effect of simultaneous colour contrast on synaesthetic colours.
abstract: We investigated whether simultaneous colour contrast affects the synaesthetic colour experience and normal colour percept in a similar manner. We simultaneously presented a target stimulus (i.e. grapheme) and a reference stimulus (i.e. hash). Either the grapheme or the hash was presented on a saturated background of the same or opposite colour category as the synaesthetic colour and the other stimulus on a grey background. In both conditions, grapheme-colour synaesthetes were asked to colour the hash in a colour similar to the synaesthetic colour of the grapheme. Controls that were pair-matched to the synaesthetes performed the same experiment, but for them, the grapheme was presented in the colour induced by the grapheme in synaesthetes. When graphemes were presented on a grey and the hash on a coloured background, a traditional simultaneous colour-contrast effect was found for controls as well as synaesthetes. When graphemes were presented on colour and the hash on grey, the controls again showed a traditional simultaneous colour-contrast effect, whereas the synaesthetes showed the opposite effect. Our results show that synaesthetic colour experiences differ from normal colour perception; both are susceptible to different surrounding colours, but not in a comparable manner.
authors.affiliation: Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands. t.c.w.nijboer@uu.nl
authors.forename: Tanja C W
authors.initials: TC
authors.lastname: Nijboer
authors.forename: Titia
authors.initials: T
authors.lastname: Gebuis
authors.forename: Susan F
authors.initials: SF
authors.lastname: te Pas
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: van der Smagt
mesh_terms: D000328:Adult; D003116:Color; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D004192:Discrimination, Psychological; D006801:Humans