Possibly even more interesting than it seems

What could I be talking about? Well, really, a lot of things. As it happens, today I am talking about synesthesia.

Tyler Cowen over on MR recently linked to a study into time-space synesthesia, which stuck me as sounding even cooler than your more garden variety letter-colour synesthesia.

Well, judging by the abstract, its not signficantly cooler after all, but then maybe it's more adaptive. After all, we devote substantial educational resources teaching people to visualise time as space, anyway: this is how to read a clock, this is how to read a displacement-time graph, and so on and so forth. In fact, it'd be nice to see some research done with young kids, or on heritability - to try and see how much of the effect measured in this study is genuinely "hard-wired" neural diversity, and how much is an acquired cognitive skill, akin to driving, or doing abstract algebra, rather than part of a person's genetic heritage. For that matter, if it is an acquired or at least acquirable ability, can we, and should we, set out to turn toddlers into synesthetics, of any variety? I'd say the possibilites are worth investigating, at the very least.

"OK, that's all great," you might be tempted to interject at this point, "but your post title implied that your subject was somehow more interesting than it seems, and yet you've just remarked that this fancy schmancy form of synesthesia is 'not significantly cooler' than the kind I already knew about. So what's so damn interesting about it then?"

Thanks for the interjection! It conveniently allows me to return from a tangent to the point I wanted to make.

Time-space synesthesia isn't all that exotic, perhaps. However, this study is yet another piece of the mounting evidence the synesthesia is actually rather commonplace in the general population. Which is really surprising, when you think about it. Surely mental differences of this kind that strike us as unusual can't be common - or else we'd grow up knowing about them, and they therefore wouldn't in fact seem unusual anymore than some other mild deviation from the norm, such as left-handedness?

Except synesthesia is such a pervasive part of a person's cognitive framework, that many synesthetics presumably grow up assuming everyone sees the world the way they do. Why wouldn't they? And, since they don't behave radically different from your average member of the population, why would anyone else think to ask the kind of questions and perform the kinds of tests necessary to detect synesthetics? Well, no one really has, until modern psychology took a a scientific interest in the phenomenon.

So, then, imagine a truly exotic synesthsia - just as difficult to detect as the regular kind, but rarer, and stranger. Given how long it has taken the "boring" synestheisas to gain serious attention, it is surely not beyond the realms of possibility that a truly rare version might exist which modern science does not yet have any knowledge of whatsoever?

It is fair to ask, at this point, just how exotic could it be? There's a limited set of senses to combine, right?

Actually, overlapping sensory perceptions here can be broader than the senses that might immediately spring to mind - as the time/space example shows.

Consider, if you will, what you might call the empathetic sense - a person's intuitive reading of other people's body language, facial expressions, tone of voice, and so on. This is an incredibly complex data source that the brain has evolved to devote many resources to detecting and processing; it sits at the threshold of may people's conscious awareness.

Now imagine a potential colour-empath synesthetic. They might look at an angry parent, and their brain would present that mood as a visible red colour. Or a distressed colleague might appear purple - perhaps with a green tint to indicate mild sleepiness. Or whatever.

You doubtless see where I'm going with this.

Of course, most people who claim to see auras are probably just cranks, or wishful thinkers. Certainly anyone who claims to see a person's aura through an opaque wall, for an example, is probably just as likely to claim to see the aura when no person is on the other side at all - as repeated experiments have shown.

There is an appeal, though, to the idea that in this case fact might be, if not stranger than fiction, than at least strange enough to surprise us.

Stay tuned for a later post in which I try to tie this into ideas about other forms of cognitive atypicality (most especially that staple topic of mine, psychosis....)