From New Scientist: "THE word "synaesthesia" derives from the phrase "joining of the senses", but the phenomenon might not be the uncontrollable perceptual mishmash that this implies. Instead, the condition may be the result of a special ability in the "higher" brain areas used for language and attention. Earlier experiments found that people with colour-grapheme synaesthesia, who link numbers and letters with certain colours, are incredibly speedy at a certain task. That is identifying hidden shapes formed out of one number or letter that are embedded in a sea of different, similar-looking characters: a pattern made up of "2"s on a background of "5"s, for example. It was assumed that they automatically imbue the numbers with different colours, causing the hidden pattern to "pop out" as soon as they glance at the display." - Mark Trapp from Bookmarklet

"Now Jamie Ward at the University of Sussex in Brighton, UK, and colleagues offer a different explanation. They had 36 colour-grapheme synaesthetes sit a similar test. When given just 1 second to identify the hidden shape, the synaesthetes were more likely to spot it than controls. But they still only found it about 40 per cent of the time. Volunteers' descriptions of the trial offer insights into why this is. "I only see the colours in the part that I am looking at," said one. "I have to attend to the symbols," said another (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2009.1765)." - Mark Trapp

Ida Maria has synaesthesia - RAPatton from iPhone

Time is spatially located for me, and I see colors when I think of months. Interesting that it might actually be a higher-order brain function: I always thought my deal was just something that grew out of memorization and computation techniques, not some brain defect. - Mark Trapp

To me things are either #000000 or #FFFFFF. No #CCCCCC areas. - Andrew Smith

Yeah, when I think of March, it's in front of me in the 2 o'clock position. February to the left of it, April to the right of it. September is in the 8 o'clock position. When I think of years, it's on a ribbon that wraps around; 2009 is in the front, 2001 is the the left of 2009, 1999 is behind 2001, 1990 is behind 1999, and so on. When I think of a year, I always see the timeline around a year: I never just see 1888. Times during the day are on a horizontal bar in front of me: 12:00pm is in the 11 o'clock position, whereas 4:00pm is in the 1 o'clock position - Mark Trapp

Okay, that sounds weird when I actually write it out. - Mark Trapp

I can't comment on the other forms of synesthesia, but I suspect the color/grapheme form occurs because reading isn't something we're automatically wired for, and the brain has to co-opt some other functions to do the processing. - Victor Ganata

Meg: it's much like a number line, but for years and times, it's visually like a ribbon that I can zoom in and out on: a thick bar with the years right in the middle. Something like this: http://fineartamerica.com/images-... - Mark Trapp