Excerpt: "Born on a Blue Day," by Daniel Tammet

Jan. 15, 2007— -- Born with a rare condition called Savant Syndrome, Daniel Tammet sees the world like few other people.

To Tammet, numbers have shapes, emotions have colors, and math is as easy as blinking. He can learn to speak a language fluently from scratch in a week and has a complusive need for order and routine.

In "Born on a Blue Day: A Memoir of Aspergers and an Extraordinary Mind," Tammet lets readers in on how his mind works. Not only does "Born on a Blue Day" provide a a fascinating portrayl of a man with unique talents, it also offers insight into the power of the human brain.

Blue Nines and Red Words

I was born on January 31, 1979 -- a Wednesday. I know it was a Wednesday, because the date is blue in my mind and Wednesdays are always blue, like the number 9 or the sound of loud voices arguing. I like my birth date, because of the way I'm able to visualize most of the numbers in it as smooth and round shapes, similar to pebbles on a beach. That's because they are prime numbers: 31, 19, 197, 97, 79 and 1979 are all divisible only by themselves and 1. I can recognize every prime up to 9,973 by their "pebble-like" quality. It's just the way my brain works.

I have a rare condition known as savant syndrome, little known before its portrayal by actor Dustin Hoffman in the Oscar-winning 1988 film Rain Man. Like Hoffman's character, Raymond Babbitt, I have an almost obsessive need for order and routine which affects virtually every aspect of my life.

For example, I eat exactly 45 grams of porridge for breakfast each morning; I weigh the bowl with an electronic scale to make sure. Then I count the number of items of clothing I'm wearing before I leave my house. I get anxious if I can't drink my cups of tea at the same time each day. Whenever I become too stressed and I can't breathe properly, I close my eyes and count. Thinking of numbers helps me to become calm again.

Numbers are my friends, and they are always around me. Each one is unique and has its own personality. The number 11 is friendly and 5 is loud, whereas 4 is both shy and quiet -- it's my favorite number, perhaps because it reminds me of myself. Some are big -- 23, 667, 1,179 -- while others are small: 6, 13, 581. Some are beautiful, like 333, and some are ugly, like 289. To me, every number is special.

No matter where I go or what I'm doing, numbers are never far from my thoughts. In an interview with talk show host David Letterman in New York, I told David he looked like the number 117 -- tall and lanky. Later outside, in the appropriately numerically named Times Square, I gazed up at the towering skyscrapers and felt surrounded by 9s -- the number I most associate with feelings of immensity.

Scientists call my visual, emotional experience of numbers synesthesia, a rare neurological mixing of the senses, which most commonly results in the ability to see alphabetical letters and/or numbers in color. Mine is an unusual and complex type, through which I see numbers as shapes, colors, textures and motions. The number 1, for example, is a brilliant and bright white, like someone shining a flashlight into my eyes. Five is a clap of thunder or the sound of waves crashing against rocks. Thirty-seven is lumpy like porridge, while 89 reminds me of falling snow.

Probably the most famous case of synesthesia was the one written up over a period of thirty years from the 1920s by the Russian psychologist A. R. Luria of a journalist called Shereshevsky with a prodigious memory. "S," as Luria called him in his notes for the book The Mind of a Mnemonist, had a highly visual memory which allowed him to "see" words and numbers as different shapes and colors. "S" was able to remember a matrix of 50 digits after studying it for three minutes, both immediately afterwards and many years later. Luria credited Shereshevsky's synesthetic experiences as the basis for his remarkable short- and long-term memory.

Using my own synesthetic experiences since early childhood, I have grown up with the ability to handle and calculate huge numbers in my head without any conscious effort, just like the Raymond Babbitt character. In fact, this is a talent common to several other real-life savants (sometimes referred to as "lightning calculators"). Dr. Darold Treffert, a Wisconsin physician and the leading researcher in the study of savant syndrome, gives one example, of a blind man with "a faculty of calculating to a degree little short of marvelous" in his book Extraordinary People:

When he was asked how many grains of corn there would be in any one of 64 boxes, with 1 in the first, 2 in the second, 4 in the third, 8 in the fourth, and so on, he gave answers for the fourteenth (8,192), for the eighteenth (131,072) and the twenty-fourth (8,388,608) instantaneously, and he gave the figures for the forty-eighth box (140,737,488,355,328) in six seconds. He also gave the total in all 64 boxes correctly (18,446,744,073,709,551, 616) in forty-five seconds.