Daniel Tammet - The Boy With The Incredible Brain [2/5]

The concept was popularised by the hit movie Rain Man, where actor Dustin Hoffman plays the part of a brilliantly gifted misfit. Like Rain Man, most savants lack normal social skills, often because they're autistic. In fact, the link with autism is so strong that we wondered whether it could be a factor in Daniel's abilities. Cambridge neuroscientist Professor Simon Baron-Cohen, an expert on autism, will be making a careful assessment. Autism is a spectrum of medical conditions where people have a lot of difficulty in forming social relationships and in putting themselves into other people's shoes to imagine other people's thoughts and feelings. But it's also where the individual develops very strong, narrow interests, obsessions, and likes to do things in a very repetitive way. So it's a mix of ability and disability. 25-year-old Daniel seems to have lots of ability, yet no obvious disability. Today he's joined by his mother, who will help to reconstruct Daniel's childhood. Her memories, it turns out, are still vivid. If you had Daniel as a first child, you'd never have another child because the constant crying. Up until nearly the age of two, he was a real handful. He would just cry, constantly. We took to even swinging him in a blanket. His dad would be at one end of the blanket, I would have the other, and we resorted to that out of desperation. Did he like that? Yes, that soothed him. Did he like the sort of repetitive movements? Yes. Yes, that soothed him. The repetition seemed to soothe him, and that's again a very sort of classic autistic characteristic. I mean, if you think back to the days when he was at primary school, were the teachers at all concerned about him, or did they talk about him as if he was different in some way? You know, what would happen during break time? I think I would count stones, I remember counting stones. And also there was a... Is it called hopscotch? Yeah. So I would count the numbers on the hopscotch. This was what interested me, so this is what I would do, and nothing else mattered. I knew he didn't integrate that well. I do remember you walking round the playground and looking up at the trees. I'd walk around the trees and look at the leaves, look at the patterns on the leaves and the bark. It seems to have the complexity within its shapes and textures that reminds me of numbers. Right. Numbers, for me, have always been the most real thing for me. From the time I was about five, I've almost looked through numbers. Numbers have been my lens, the way that I've looked at the world around me, so I'll always count things. So I'll look at something and say, that looks like 131, for example, or that looks like 52. And just always thinking that this is how everyone else experiences numbers, you know, that this is a normal thing. He got most pleasure out of just taking the maths books home and lying on his bedroom floor alone, going as far as he could with numerical problems and just understanding numbers, feeling much more comfortable in a world of numbers than people. Daniel's obsession with maths is at least part of the explanation for his special ability with numbers. The things that he always felt were his friends. Because I was so different, the children who would be bullies didn't know what to do with me. They didn't know how to teach me, so they just let me be, pretty much. By most measures, Daniel is autistic, but he's also picked up enough social skills to blend in. The one criterion that really is missing to warrant a diagnosis is that his symptoms are not really interfering currently with his life. For whatever reason, he's managed to adapt to our world. Daniel is lucky. Rare abilities like his usually come with severe mental handicap as part of the price. Dane Bertino is a savant too, but very different from Daniel. For one thing, his gift is not the maths. We knew by two and a half that Dane wasn't talking, but instead he was just expressing himself through art. He was drawing night and day. Since he was a toddler, Dane has been able to draw with extraordinary precision. But there's always been a flip side to his talent. What do you want to do? Dane's language and social skills remain childlike, even as his art becomes richer. He really pays attention to the little minute details, but he would put the emotion in. He loves drawing in the sand, and he enjoys watching the waves come in and wash it away, and then draw something else, because he draws really quickly, so he likes to see things change so that he can draw something new. How is this remarkable boy seeing the world? It would be fascinating to know, if only he could tell us. What makes Daniel different from savants like Dane, and so extremely valuable to science, is that he can describe what's going on inside his head. I experience numbers in a very visual way, using colours, texture, shape and form. Sequences of numbers form landscapes in my mind. It just happens. It's like having a fourth dimension. One, for example, would be very bright, very bright and shiny numbers. It's almost like somebody flashing a light in my face. It's a very interesting experience. Number two is kind of like a movement, right to left, kind of like a drifting motion. Five is like the clap of thunder, or the sound of a wave against a rock. Six is very small, it's actually the number I find hardest to experience in any sort of meaningful visual way, so it's often the absence of anything. It's like a hole, or a chasm, or like a black hole. Number nine is the biggest number, it's very tall. It can be intimidating. Daniel says he sees every number, up to 10,000, as a distinct shape or image. Until recently, many researchers would have dismissed this as mumbo-jumbo. But there is now a sound, scientific explanation. Different parts of our brain are specialised with different tasks. Juggling numbers, for example, or seeing shapes. If cross-activation occurs between areas that are normally separate, then things can get very mixed up. You might hear a sound, and see a colour, or think a number and feel emotion. Scientists call this weird phenomenon synesthesia. Julian Asher, a researcher at Cambridge University, experiences synesthesia himself, but is struck by how peculiar it is in Daniel. For most synesthetes, what they see is much more abstract. For instance, I see what almost might be coloured flames, this sort of a flickering, flowing movement. But Daniel sees very concrete shapes, which is quite unusual. Is the entire number drifting upwards? Yes. Julian believes that Daniel's complex imagery is the key to his gigantic memory. When he's recalling a number, the 22,500 digits, what he's doing is moving mentally through a synesthetic landscape, and effectively reading the numbers from the landscape. But are Daniel's number shapes also the key to his maths ability? To find out more, we're sending him to San Diego's Centre for Brain Studies in California, where he'll be grilled by sceptical scientists. First, though, he'll be travelling across America and putting some of his mental powers to the test.