I like the brain, and unusual brain activity intrigues me, whether it's coping with damage, insanity, or a glitch like autism. One of the most interesting eccentricities of the brain is synaesthesia. It's interesting, because it is one of the few brain eccentricities which is inducable. You can cause synaesthesia with cimertain chemicals. Although these are called 'hallucinogenic' experiences, that's a rather shifty description.
You see, a synaesthetic person isn't seeing (or hearing, or feeling) things which aren't there. They are seeing/hearing/feeling things which ARE there - just in the wrong way. It is occasionally suggested that you can tell how many drugs a poet takes by counting the number of cross-sensory phrases, such as "yellow music" or "picture tasted like blood". I don't know if this is accurate, but it is interesting.
ANYWAY, I've always been very curious about synaesthesia, in all its dozens of forms.
There is a trickle of information about this disorder, and it's starting to point to an interesting but highly believable result: Synaesthesia is largely the result of the "primary filters" being spazzy or even shutting off entirely.
When you 'see' something, there's a part of your brain which lights up like a Christmas tree. That part of your brain translates what you see into a regulated pattern, dropping the useless stuff, highlighting and "tagging" the useful stuff. That tagged information filters into the rest of your brain, which figures out what to do with it.
In synaesthetics, it seems those parts of the brain screw up, and the sensory input is passed straight through to the rest of your brain. Not only does this include more data, it also comes in wholly unfiltered and mistagged.
The rest of your brain interprets this 'noise' as best it can. As a result, a lot of the random crap is imported as a different piece of a the correct sense, a different sense, or even an emotion!
This is pretty cool and makes a lot of sense to me. It does make me wonder what kind of effect crosswiring those systems has on how the person thinks and acts.
One thing I find extremely interesting are the folk who sense things when they look at, say, numbers. This is the most common variety of synaesthesia, but there's more than one variety of this variety. For example, some savants explain that they have a synaesthetic number "sense". A two might be a clap of thunder, and a seven a shade of yellow. Magically, these hooks allow for or accompany incredible feats of mathematics. This kind of synaesthesia is usually found with some bizarre glitches elsewhere in the brain, commonly in the language/social centers.
But that's obviously not true of all synaesthetics who perceive numbers aesthetically, although the miswiring often allows them to remember number strings more clearly due to a better set of memory hooks.
Similarly, some excessively talented composers report that they see or feel music, but have no other kinds of synaesthesia.
Perhaps these parts of the brain go into 'overdrive' and start 'conquering' nearby portions of the brain, instead of partially shutting down like in 'normal' synaesthetics. The additional 'territory' screws up the perceptions a little, but offers increases in both emotional and logical computing hooks and power.
Perhaps they have 'normal' synaesthesia, but concentrate on it to such an extent that it becomes a well-honed gift?