Autism is a mental disease which prevents those who suffer from it from communicating with the outside world. Victims seem to live in a world of their own which, even now, doctors are unable to penetrate. The illness was first given a name in 1943, and yet doctors have made very little progress in their understanding of the disease since then. According to statistics, between two and four children out of every 10,000 are born autistic.

Often victims are not able to speak, read or write. But what is most extraordinary about the illness is the fact that in other areas many of the children can use their brains in ways which are almost superhuman. One of the more common skills these so-called autistic savants have is calendrical calculation, that is the ability to say which day of the week a particular date falls on. Jackie, for instance, who is now 42, could do this from the age of six, when she first began to talk. She can tell you what day of the week it was on 1 April 1993 with scarcely a moment's hesitation. But if you ask her how she does it, she'll say she doesn't know.

Source: Bridging the Gap