Synesthetic colors determined by having colored refrigerator magnets in childhood

Synesthesia is a condition in which percepts in one modality reliably elicit secondary perceptions in the same or a different modality that are not in the stimulus. In a common manifestation, synesthetes see colors in response to spoken or written letters, words and numbers. In this paper we demonstrate that the particular colors seen by a grapheme-color synesthete AED were learned from a set of refrigerator magnets and that the synesthesia later transferred to Cyrillic in a systematic way, with the colors induced by the Cyrillic letters determined by their visual or phonetic similarity to English letters. Closer examination of the data reveals that letters of either language that are more visually similar to the English capitals in the magnet set are also more saturated. In order to differentiate AED's synesthesia from ordinary memory, we use a novel psychophysical method to show that AED's synesthetic colors are subject to ordinary lightness constancy mechanisms. This suggests that the level of representation at which her synesthesia arises is early in the stream of visual processing.