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Updated: Jun 24, 2026

Training Synesthetic Letter-color Associations by Reading in Color
Published on: February 20, 2014
Of colored numbers and numbered colors: interactive processes in grapheme-color synesthesia
Titia Gebuis1, Tanja C W Nijboer, Maarten J van der Smagt
1Experimental Psychology, Helmholtz Institute and Utrecht University, 3584 CS Utrecht, The Netherlands. T.Gebuis@uu.nl
Abstract:
Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions. Interestingly, the congruency effect was of similar magnitude for both conditions, and a numerical distance effect was present only in the color-number priming task. In addition, a priming task in which synesthetes had to judge the parity of a colored number revealed faster responses in parity congruent than in parity incongruent trials. These combined results demonstrate that synesthesia is indeed bi-directional and of similar strength in both directions. Furthermore, they illustrate the precise nature of these interactions and show that the direction of these interactions is determined by task demands, not by the more vividly experienced aspect of the stimulus.
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