Attention, Perception, & Psychophysics

, Volume 71, Issue 7, pp 1461–1467 | Cite as

Searching through synaesthetic colors

  • Bruno LaengEmail author
Brief Reports


Synaesthesia can be characterized by illusory colors being elicited automatically when one reads an alphanumeric symbol. These colors can affect attention; synaesthetes can show advantages in visual search of achromatic symbols that normally cause slow searches. However, some studies have failed to find these advantages, challenging the conclusion that synaesthetic colors influence attention in a manner similar to the influence of perceptual colors. In the present study, we investigated 2 synaesthetes who reported colors localized in space over alphanumeric symbols’ shapes. The Euclidian distance in CIE xyY color space between two synaesthetic colors was computed for each specific visual search, so that the relationship between color distance (CD) and efficiency of search could be explored with simple regression analyses. Target-to-distractors color salience systematically predicted the speed of search, but the CD between a target or distractors and the physically presented achromatic color did not. When the synaesthetic colors of a target and distractors were nearly complementary, searches resembled popout performance with real colors. Control participants who performed searches for the same symbols (which were colored according to the synaesthetic colors) showed search functions very similar to those shown by the synaesthetes for the physically achromatic symbols.


Control Participant Visual Search Task Slope Coefficient Search Function Search Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Dixon, M. J., Smilek, D., Duffy, P. L., Zanna, M. P., & Merikle, P. M. (2006). The role of meaning in grapheme-colour synaesthesia. Cortex, 42, 243–252.CrossRefPubMedGoogle Scholar
  2. Dixon, M. J., Smilek, D., & Merikle, P. M. (2004). Not all synaesthetes are created equal: Projector versus associator synaesthetes. Cognitive, Affective, & Behavioral Neuroscience, 4, 335–343.CrossRefGoogle Scholar
  3. Duncan, J., & Humphreys, G. W. (1989). Visual search and stimulus similarity. Psychological Review, 96, 433–458.CrossRefPubMedGoogle Scholar
  4. Edquist, J., Rich, A. N., Brinkman, C., & Mattingley, J. B. (2006). Do synaesthetic colours act as unique features in visual search? Cortex, 42, 222–231.CrossRefPubMedGoogle Scholar
  5. Howell, D. C. (1987). Statistical methods for psychology (2nd ed.). Boston: Duxbury.Google Scholar
  6. Hubbard, E. M., Arman, A. C., Ramachandran, V. S., & Boynton, G. M. (2005). Individual differences among grapheme-color synesthetes: Brain-behavior correlations. Neuron, 45, 975–985.CrossRefPubMedGoogle Scholar
  7. Laeng, B., Svartdal, F., & Oelmann, H. (2004). Does color synesthesia pose a paradox for early-selection theories of attention? Psychological Science, 15, 277–281.CrossRefPubMedGoogle Scholar
  8. Martino, G., & Marks, L. E. (2001). Synesthesia: Strong and weak. Current Directions in Psychological Science, 10, 61–65.CrossRefGoogle Scholar
  9. Palmeri, T. J., Blake, R., Marois, R., Flanery, M. A., & Whetsell, W., Jr. (2002). The perceptual reality of synesthetic colors. Proceedings of the National Academy of Sciences, 99, 4127–4131.CrossRefGoogle Scholar
  10. Reijnen, E., Wallach, D., Stöcklin, M., Kassuba, T., & Opwis, K. (2007). Color similarity in visual search. Swiss Journal of Psychology, 66, 191–199.CrossRefGoogle Scholar
  11. Rich, A. N., Bradshaw, J. L., & Mattingley, J. B. (2005). A systematic, large-scale study of synaesthesia: Implications for the role of early experience in lexical-colour associations. Cognition, 98, 53–84.CrossRefPubMedGoogle Scholar
  12. Rich, A. N., & Mattingley, J. B. (2002). Anomalous perception in synaesthesia: A cognitive neuroscience perspective. Nature Reviews Neuroscience, 3, 43–52.CrossRefPubMedGoogle Scholar
  13. Rosenholtz, R. (1999). A simple saliency model predicts a number of motion popout phenomena. Vision Research, 39, 3157–3163.CrossRefPubMedGoogle Scholar
  14. Rouw, R., & Scholte, H. S. (2007). Increased structural connectivity in grapheme-color synesthesia. Nature Neuroscience, 10, 792–797.CrossRefPubMedGoogle Scholar
  15. Sagiv, N., Heer, J., & Robertson, L. C. (2006). Does binding of synesthetic color to the evoking grapheme require attention? Cortex, 42, 232–242.CrossRefPubMedGoogle Scholar
  16. Sagiv, N., & Robertson, L. C. (2005). Synesthesia and the binding problem. In L. C. Robertson & N. Sagiv (Eds.), Synesthesia: Perspectives from cognitive neuroscience (pp. 90–107). New York: Oxford University Press.Google Scholar
  17. Simner, J., Ward, J., Lanz, M., Jansari, A., Noonan, K., Glover, L., & Oakley, D. A. (2005). Non-random associations of graphemes to colours in synaesthetic and non-synaesthetic populations. Cognitive Neuropsychology, 22, 1069–1085.CrossRefPubMedGoogle Scholar
  18. Smilek, D., Dixon, M. J., & Merikle, P. M. (2003). Synaesthetic photisms guide attention. Brain & Cognition, 53, 364–367.CrossRefGoogle Scholar
  19. Treisman, A. [M.] (1982). Perceptual grouping and attention in visual search for features and for objects. Journal of Experimental Psychology: Human Perception & Performance, 8, 194–214.CrossRefGoogle Scholar
  20. Treisman, A. [M.] (1991). Search, similarity, and integration of features between and within dimensions. Journal of Experimental Psychology: Human Perception & Performance, 17, 652–676.CrossRefGoogle Scholar
  21. Treisman, A. [M.] (2005). Synesthesia: Implications for attention, binding, and consciousness. In L. C. Robertson & N. Sagiv (Eds.), Synesthesia: Perspectives from cognitive neuroscience (pp. 239–254). New York: Oxford University Press.Google Scholar
  22. Treisman, A. M., & Gelade, G. (1980). A feature integration theory of attention. Cognitive Psychology, 12, 97–136.CrossRefPubMedGoogle Scholar
  23. Wager, A. (1999). The extra qualia problem: Synaesthesia and representationism. Philosophical Psychology, 12, 263–281.CrossRefGoogle Scholar
  24. Ward, J., Li, R., Salih, S., & Sagiv, N. (2007). Varieties of graphemecolor synaesthesia: A new theory of phenomenological and behavioural differences. Consciousness & Cognition, 16, 913–931.CrossRefGoogle Scholar
  25. Wolfe, J. M. (1994). Guided Search 2.0: A revised model of visualsearch. Psychonomic Bulletin & Review, 1, 202–238.Google Scholar

Copyright information

© Psychonomic Society, Inc. 2009

Authors and Affiliations

  1. 1.Department of PsychologyUniversity of OsloOsloNorway

Personalised recommendations