This segment was originally broadcast on Jan. 28, 2007. It was updated on Sep. 5, 2007.
Almost 25 years ago, 60 Minutes introduced viewers to George Finn, whose talent was immortalized in the movie "Rain Man." George has a condition known as savant syndrome, a mysterious disorder of the brain where someone has a spectacular skill, even genius, in a mind that is otherwise extremely limited.
Morley Safer met another savant, Daniel Tammet, who is called "Brain Man" in Britain. But unlike most savants, he has no obvious mental disability, and most important to scientists, he can describe his own thought process. He may very well be a scientific Rosetta stone, a key to understanding the brain.
Back in 1983, George Finn, blessed or obsessed with calendar calculation, could give you the day if you gave him the date.
"What day of the week was August 13th, 1911?" Safer quizzed Finn.
"A Sunday," Finn replied.
"What day of the week was May 20th, 1921?" Safer asked.
"Friday," Finn answered.
George Finn is a savant. In more politically incorrect times he would have been called an "idiot savant" - a mentally handicapped or autistic person whose brain somehow possesses an island of brilliance.
Asked if he knew how he does it, Finn told Safer, "I don't know, but it's just that, that's fantastic I can do that."
If this all seems familiar, there's a reason: five years after the 60 Minutes broadcast, Dustin Hoffman immortalized savants like George in the movie "Rain Man."
Which brings us to that other savant we mentioned: Daniel Tammet. He is an Englishman, who is a 27-year-old math and memory wizard.
"I was born November 8th, 1931," Safer remarks.
"Uh-huh. That's a prime number. 1931. And you were born on a Sunday. And this year, your birthday will be on a Wednesday. And you'll be 75," Tammet tells Safer.
It is estimated there are only 50 true savants living in the world today, and yet none are like Daniel. He is articulate, self-sufficient, blessed with all of the spectacular ability of a savant, but with very little of the disability. Take his math skill, for example.
Asked to multiply 31 by 31 by 31 by 31, Tammet quickly - and accurately - responded with "923,521."
And it's not just calculating. His gift of memory is stunning. Briefly show him a long numerical sequence and he'll recite it right back to you. And he can do it backwards, to boot.
That feat is just a warm-up for Daniel Tammet. He first made headlines at Oxford, when he publicly recited the endless sequence of numbers embodied by the Greek letter "Pi." Pi, the numbers we use to calculate the dimensions of a circle, are usually rounded off to 3.14. But its numbers actually go on to infinity.
Daniel studied the sequence - a thousand numbers to a page.
"And I would sit and I would gorge on them. And I would just absorb hundreds and hundreds at a time," he tells Safer.
It took him several weeks to prepare and then Daniel headed to Oxford, where with number crunchers checking every digit, he opened the floodgates of his extraordinary memory.
Tammet says he was able to recite, in a proper order, 22,514 numbers. It took him over five hours and he did it without a single mistake.