Synesthesia, which is the ability to blend senses, is one of the many faculties of the neocortex. Artists and musicians possess this quality, which enables them to see a V of flying geese at a distance, imagine the sound of their flapping wings, then set that aural and visual composition to music or canvas. Even in common language, we sometimes use synesthetic or cross-sensory descriptors to create juxtapositional idioms such as “bitter wind” or “loud color.”
Daniel Tammet, an English savant, is one person who expresses synesthetic capability to the nth degree. Tammet can, for example, recite the mathematical constant pi from memory to 22,514 decimal places and divide 97 by 13 with complete accuracy to over 100 decimal places. Some researchers propose that synesthesia and savant syndrome are strongly linked. Others argue that such great gifts come at a great price―nearly 50 percent of all savants, they say, are also autistic.
A prolific writer, Tammet’s best-selling book, Born on a Blue Day: Inside the Extraordinary Mind of an Autistic Savant, describes how he thinks. He says that when he performs a mathematical calculation, such as multiplying 37 to the power of 4, which he can do faster than you can press the numbers on a calculator, the answer comes to him in a rich, kaleidoscopic confluence of colors, textures, shapes, hues, and feelings.
Diagnosed with high-functioning autism, Tammet developed his extraordinary capabilities after a series of epileptic seizures during childhood that may have rewired his brain, allowing him to tap into a limited range―a deep but narrow slice―of his neocortical capabilities.
Daniel Tammet’s gifts are not limited to mathematics. For a television special, he mastered the complex and difficult Icelandic language―which contains, for example, 12 words for each of the numbers one, two, three, and four, depending on the context and a strict adherence to gender agreement between nouns and adjectives―in less than a week. This enabled him to conduct a live interview on Icelandic television in the native language, a task that he performed flawlessly. Tammet speaks eight other languages with equal fluency.
Wisconsin psychiatrist and researcher Darold Treffert suggests that savant syndrome is caused by damage to the left brain hemisphere, particularly the frontal areas, which causes the right hemisphere to overcompensate. He believes the rewiring that takes place after such injury is accompanied by a shift from high-level frontal lobe memory and processing to low-level procedural memory, which allows persons like Daniel Tammet to master numbers and languages with such ease.
Orlando Serrell, an “acquired savant,” was a typical 10-year-old until he was accidentally struck by a baseball as he ran toward first base. The blow to the left side of his head was so hard, it knocked him out. Sometime later he discovered he could easily recall the day of the week and the weather for any date since his accident.
“June 3, 1985 was on a Monday; it was hot. March 28, 1990 was on a Wednesday; clear skies,” he recites rapidly. “I can’t explain it, it just pops right into my head.” In addition to enhanced memory, he also developed a heightened sense of perception.
Perception is something Daniel Tammet often brings up during his speaking engagements. “Personal perceptions are at the heart of how we acquire knowledge,” he told a TED audience. “Different kinds of perception create different kinds of knowing and understanding.”
These experiences are not unlike those of sages in the high Andes who claim that extraordinary telepathic, clairvoyant and perceptive skills appeared shortly after they were struck by lightning, or after a strenuous vision quest of fasting and praying for numerous days.