When blue is larger than red: colors influence numerical cognition in synesthesia.
In synesthesia, certain stimuli ("inducers") may give rise to perceptual experience in additional modalities not normally associated with them ("concurrent"). For example, color-grapheme synesthetes automatically perceive achromatic numbers as colored (e.g., 7 is turquoise). Although synesthetes know when a given color matches the one evoked by a certain number, colors do not automatically give rise to any sort of number experience. The behavioral consequences of synesthesia have been documented using Stroop-like paradigms, usually using color judgments. Owing to the unidirectional nature of the synesthetic experience, little has been done to obtain performance measures that could indicate whether bidirectional cross-activation occurs in synesthesia. Here it is shown that colors do implicitly evoke numerical magnitudes in color-grapheme synesthetes, but not in nonsynesthetic participants. It is proposed that bidirectional coactivation of brain areas is responsible for the links between color and magnitude processing in color-grapheme synesthesia and that unidirectional models of synesthesia might have to be revised.
Cohen Kadosh
Roi
R
Ben-Gurion University of the Negev, Israel. roico@bgu.ac.il
Sagiv
Noam
N
Linden
David E J
DE
Robertson
Lynn C
LC
Elinger
Gali
G
Henik
Avishai
A
D000328:Adult; D003071:Cognition / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D005260:Female; D005556:Form Perception / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology