Iasbel Hilton talks to Daniel Tammet, author of Embracing The Wide Sky, the second in a volume of memoirs about growing up and living with Asperger's Syndrome. He traces his life story from difficult childhood through adolescence to adult independence and subsequent career success. Tammet is an autistic savant - one of eight children born to working-class parents - who is capable of incredible feats of mental arithmetic and memorisation. In the space of one week he learned Icelandic, and he can recite the number pi up to the 22,514th digit, breaking the European record. Tammet's condition is complicated by the fact that he also experiences synaesthesia, which enables him to feel numbers and words as shapes and colours.