New research has unearthed that the grapheme-color synesthesia is not idiosyncratic , but follows some typical patterns. Grapheme – color synesthesia is one of the common types of synesthesia wherein one sees color associated with visualizing an alphabet / letter. Thus, whenever one see the alphabet ‘A’ one may also have a perception of color ‘red’. Till now, it was believed that this association of colors with alphabets was random and idiosyncratic; but new research has now revealed that it follows a pattern with most synesthetes more likely to associate typical colors with alphabets and for example report ‘A’ as red and V as ‘purple’.
Jamie Ward’s team that found this phenomenon speculates that the hue could be associated with the frequency of the word. Thus, as ‘A’ is a frequently used word it is associated with a common color ‘red’. ‘V’ which is infrequently used in the lexicon is associated with a similar infrequently encountered color purple. I am not sure how their new study is different from their earlier study that also found thus association and I believe that there would be some truth to their theory. however, the science daily article also talks about saturation. So I though I would jump in.
Colors can be conceptualized as per the HSV/ HSL or HSB system and understood in terms of hue , saturation and value/ brightness. I would personally be inclined to interpret the ‘A’ is red and ‘V’ is purple mapping as the outcome of a mapping of the alphabet order (a, b, c, ….x, y, z) to the color order in the rainbow / hue dimension (VIBGYOR). ‘A’ is one end ofthe spec trim and thus red in color, while ‘V’ is on another end of spectrum and thus more likely to be ‘violet’ in color. The frequency of usage of the alphabet should ideally map to brightness/ value of the synesthete color as in color space value is mapped to the amount of light reflected. saturation or ‘purity’ of color is a bit difficult to map onto the alphabet; but one could venture forth and suggest it has to do with how ‘pure’ the alphabet is ….is it always pronounced in one way….or are their multiple pronunciations associated with the same alphabet.
Mapping a linear progression of hues along VIBGYOR axis to alphabet order or numeral oredr is not that hard to envisage or visualize. If neurons of adjacent colorotopic and lexicotopic maps (assuming there are such maps for color and lexicon in the brain) in the brain overlap/ cross-over we would have the phenomenon of grapheme-color synestehesia that accounted for the commonalities in hues and alphabet association. However, we just know of retinotopic sort of maps in brains and these fit in with our existing knowledge. How the brain stores information about saturation/ value and correspondingly frequency and purity of alphabets and maps between the too, can lead to novel insights as to how information is stored in the brain.
I am excited and believe that we are on verge of breaking new ground ( I haven’t read the new Jamie ward paper though yet) and I have my own theories on why color is so important and may provide us many more clues (color and music are two most interesting phenomenon I believe). Are you excited? Do you have any theories?
PS: I just found that Jamie Ward is writing a book called “The Frog who Croaked Blue: Synaesthesia and the Mixing of the Senses” in which he recounts the experience of a synesthete who heard frog croaks as blue and chirping of cricket as red. To me this immediately conjures up the colortopic map with red at one end (high, feminine, shrill noises) and blue at the other (more manly, bass noise). This mapping of sound with colors may again follow the hue, saturation and value (three dimensions) with loudness of sound being proportional to the value of color being perceived and the hue and pitch mapped. Also , this may be an idiosyncratic experience, or this may be true of the species as a whole that we map more shrill noises to red and soothing and duller sounds to blue/ violet.