From Eric Clapton to Miles Davis to Yo-Yo Ma, we’ve long heard that when musicians improvise, they’re engaged in an intensely personal pursuit. A pair of scientists have scanned musicians’ brains and now say that’s true.

More precisely, when musicians improvise, they’re using the same part of the brain that responds to a simple request: Tell me about yourself.

In new findings, researchers at Johns Hopkins University in Baltimore and the National Institute on Deafness and Other Communication Disorders say they have located the region of the brain — the medial prefrontal cortex — that lights up when musicians improvise. It’s the same area we all use when we’re talking about ourselves — who we are, what makes us tick.

It makes perfect sense to Charles Limb, a Hopkins researcher and jazz saxophonist who holds a joint faculty appointment at Hopkins’ music conservatory. “Because the person is spontaneously composing, they really are revealing themselves musically,” he says. “It’s like your own musical autobiography.”

At the same time, he and a colleague found, improvising musicians turn off the dorsolateral prefrontal cortex, a portion of the brain linked to planning, careful actions and self-censoring.

Limb says most writing about jazz has traditionally stressed how great musicians “find their own sound.” Now, he says, we know what that means in scientific terms: “It’s basically sculpting your own identity, the voice you’re going to use.”

And he has the brain scans to prove it.

Limb and a colleague, Allen Braun of the communication disorder center, designed an unusual experiment. They recruited six jazz pianists to play a specially designed keyboard while lying on their backs in a functional magnetic resonance imaging (fMRI) machine.

Subjects played scales, simple memorized pieces and improvisations on both. During the improvisations, a recorded jazz group played in their headphones.

When Limb and Braun examined the scans produced during…