According to the journal Scientific Reports, tone deaf people are much less skilled than those with a musical ear to read other people’s emotions. They have trouble recognising false laughter, or angry voices or expressions. I imagine that may put them at a disadvantage when they spill someone’s pint in a pub.

As luck would have it I read this a couple of days after a Beeb programme on senses that rendered me a gibbering wreck. More gibbering, I should probably say. It started with a somewhat contentious statement from a perceptual psychologist (huh?) who claimed quite boldly that seeing is believing. He illustrated this partly by showing illusionists at work.

I took a bit of an exception to this. Look at the figure below.


You’ll have seen one before. It’s called a Necker cube, and although it’s just a two dimensional grid, your brain goes bonkers because a/ it looks three dimensional, and b/ your head can’t work out if it projects ‘out of’ or ‘into’ the page. The thing is you don’t believe it, you know your head is playing tricks. In this case seeing is not believing, any more than you believe that that idiot David Blain can throw a deck of cards through a window. You don’t know how he makes it look as if he did, but you know he couldn’t possibly have done. It’s a parlour game.

Then we strayed into the weird realm of synaesthesia, where there’s a crossover between the senses. Again you all know about this. When I was at university, all my friends who smoked said they couldn’t taste the ciggie/joint if they couldn’t see the smoke.

This is a phenomenon well known to food manufacturers, which is why you don’t get many foods that are blue, because we don’t associate that colour with things tasting good. Put somebody in a darkened room, the blue stuff tastes all right.

True synaesthetes aren’t as rare as you may think. There are people who see smells as colours, for whom sounds have textures. All in all you might think their brains would go ‘Pop!’ with all the information.

I’ll let you into a little secret. For me, the numeral 4 is blue. If I see it printed in red, for example, I have to do a doubletake. The word ‘orange’ is paradoxically golden. Now you know why my head is how it is.

And if the Necker cube makes your brain hurt, try this on for size.