I'm not sure it causes confusion in the brain. It doesn't make them very happy though. It's not a nice thing to do any more than it is to make someone do anything that they wouldn't naturally do. There used to be an idea that it mixed up the circuitry in the brain, but I think the circuitry in the brain is a bit more fixed than that.

For most people that we've met that have synesthesia, it has started when they were very young. It was therefore likely to be there before you had a tumour.

We think it's the old fashioned billion (1012), which is a lot. But guess what your brain is mostly made of? It's actually not nerves. For every nerve cell there are ten other cells that are not nerves and they're there to hold it all together like a scaffolding. As for black holes, they are very very powerful. The reason we know this is because it's black. The reason it's black is because it has such a powerful magnetic field that it can't even let light escape. So when light goes past a black hole, it sucks it in like a giant hoover and makes it disappear. That's why it looks black. I can't really answer exactly how powerful a black hole is because the universe is so enormous that if I say that a black hole is 'x' powerful, there will always be one somewhere more powerful that we haven't discovered yet. So I'm going to sit on the fence and say that I can't answer that.

It's almost certainly genetic, but it's not very obvious always. And yes, they can more talented, especially mathematically and in the visual-spatial arts. Different people have their brains organised in different ways. The genes Seth was talking about wire people up in different ways and make different combinations. We tend to assume that every brain is the same as every other brain, but every brain is fundamentally different. This gives some of us talents in one thing but make us not so good at others.

I think what she's getting at here is that if you listen back to a recording of yourself you sound subtly different to how you think you sound. When you listen to a person speaking, the air transmits the sound, goes into my ear and wiggles the ear drum and the bones of the middle ear and eventually makes electrical impulses. When I hear myself speaking, the sound not only goes through the air but also through the bones of my skull. So when my jaw is moving I'm making the bones vibrate directly, and therefore it sounds different. That's probably the explanation.

When its head was chopped off, a tiny part of the head called the brain stem, which links the spinal cord to the top of the brain, was left intact. That's the part of the brain that control breathing, circulation and heart rate, so the chicken had just enough brain left to keep the physiological processes going. They fed it with a tube down its neck for seven years.