Michael, a subject of The Man Who Tasted Shapes by Dr. Richard Cytowic, prefers his chicken to taste prickly, "as if you were laying your hand on a bed of nails." Michael's synesthesia, documented in the book, causes him to taste shapes.

Cytowic is a rare mix for a research neurologist. The son of an artist and a physician, his career has been about plumbing the connections between the two. He's been nominated for a Pulitzer Prize and written award-winning medical biographies of playwright Anton Chekhov and composer Maurice Ravel, but his most famous work is about the unusual quirk of the human brain called synesthesia.

"All of us are synesthetic, but we're not aware of it," Cytowic says.

Lynne Rossetto Kasper: What is synesthesia?

Richard Cytowic: You know the word anesthesia, meaning "no sensation." Synesthesia means "joined sensations," wherein somebody is born with two, three or all of their senses hooked together. My voice, for example, is not only something that they hear but also something that they see, taste or touch. We call them synesthetes. They're surprised to discover as children that the rest of the world is not like them.

LRK: In the book The Man Who Tasted Shapes you worked with one particular subject named Michael. Could you describe how Michael experienced food?

RC: Michael had a very unusual kind of synesthesia, which was a combination of taste and smell with touch. He felt things all over his body, but he felt them greatest in his face and hands.

He would say with an intense flavor: "A feeling sweeps down my arm into my hands. I actually feel texture, weight and temperature as if I'm holding something." Of course he could see that there wasn't anything in his hand. But he says, "Nonetheless, it feels like I'm holding something."

LRK: I remember something about a chocolate mint pie that had 12 columns?

RC: Michael would describe things very elaborately. He was not being metaphoric but just describing the sensations. So chocolate mint, for example, he said, "I can reach out into the distance and stick my hand in among what feels like a whole bunch of smooth, glass columns."

I said, "How do you know that they're glass columns?

He said, "They're not really, but I can reach out and I can feel the curvature. It's cold to the touch, so it's got to be stone or marble, but it's so deliciously smooth. I can run my hand up and down. I can't even feel where the top or the bottom ends, so it's like a column and it must be made of glass, so that's why it feels like cold, glass columns."

LRK: He would be a wonderful food writer.

RC: He was a great dinner companion. He was very entertaining.

LRK: Did he cook?

RC: He cooked quite well. In fact, that's how we met. He was my new neighbor in North Carolina. He taught at the School of the Arts, he was a lighting designer. He invited me to dinner along with some other people.

He delayed our sitting down at the table with the comment, "Oh dear, there are not enough points on the chicken." His friends laughed and said, "What are you smoking?"

But Michael turned to me -- he was beet red -- and he said, "Maybe you'll understand, you're a neurologist. I've had this thing all my life where I taste according to touch. I wanted the chicken to be a pointed, prickly shape. It's come out all round. I can't serve this."

I said, "You have synesthesia."

To which Michael said, "You mean there's a name for this?" He thought he was the only person in the world. He thought this was a very private experience that nobody else could understand. That's a very typical sentiment among synesthetes.

LRK: Could you perceive the differences in taste in that chicken that Michael was perceiving?

RC: Oh, no. To me, chicken is chicken. But Michael was disappointed because when he talked about that he wanted it to be a pointed shape, he said, "No, it needed to be a prickliness, as if you were laying your hand on a bed of nails." That's what he wanted to do.

He cooked according to the shape of things, not according to any kind of recipe or starting with "I want this to taste like thyme or garlic." No, he wanted it to have a particular shape. He loved prickly, pointed shapes. He loved round, smooth shapes.

In the early experiments that we did with him, I started out with things that were completely sour and things that were completely sweet. I mixed them up in solutions so it was very hard to tell what was 50/50, what was 70/30. He could discriminate extraordinarily well these nuances.

LRK: Were the sweets round and the sour things or the bitter things prickly?

RC: Bitter was more of a smooth inclination. The sweetness did tend to have round and columnar forms -- mostly curvature is the idea, that they were curved and he could rub the curve.

He used to love to rub textures. He would eat a pâté or something, and he would pause for half a second and go, "Mmm." He would reach his hand out over the table and you could see him moving his hand as if he were actually palpating the roughness or the smooth, oiled surface that he felt. He said, "This is so wonderful." But it only lasted a second or two and then faded away.

Synesthesia is like fireworks in the sense that there's this explosion, something appears, it kaleidoscopes a little bit and then a second or two later, it fades away. That's what synesthesia is like.

LRK: Are people with synesthesia essentially connecting more of the dots than the rest of us? I guess what I'm asking is, have they evolved further? Are their brains different?

RC: Their brains are definitely different and you can prove that with paper-and-pencil tests as well as with very fancy, million-dollar brain scans. They're not more evolved, but they're simply aware of an earlier process of evolution in which, perhaps, the senses were less divided.

It turns out that all of us are synesthetic but we're not aware of it. Synesthetes have a conscious look at an earlier stage of any kind of perceptual process. All the senses sample the world, if only just a little.

Lynne Rossetto Kasper
Lynne Rossetto Kasper has won numerous awards as host of The Splendid Table, including two James Beard Foundation Awards (1998, 2008) for Best National Radio Show on Food, five Clarion Awards (2007, 2008, 2009, 2010, 2014) from Women in Communication, and a Gracie Allen Award in 2000 for Best Syndicated Talk Show.