And what's going on is…nothing (sort of).
Limb says the most interesting thing was that one area went largely silent when the musicians switched to improvisation. That area, a part of the prefrontal cortex, is known for helping us monitor our behavior and performance.
"This is a broad expanse of brain that basically shut down during improvisation.," says Limb, adding, "One of the things it’s closely involved in is in self-monitoring, and sort of conscious evaluation of what you’re doing. So for example, to judge the appropriateness or correctness of your behavior, this area would be active."
And Limb says for jazz improv, that makes sense.
"What you want is to just generate ideas, and you don’t really want to worry too much about whether they sounded right," he says. "You don’t want to be too inhibited by that. And I think that these musicians are so proficient that they're able to enter this creative state where they’re essentially uninhibited rather easily."
For any amateur musicians out there hoping this might lead to some kind of jazz pill, that's not in the cards. But Limb says it's a unique look into the physiology of creativity, and he thinks the findings probably apply to other spontaneous artistic creations, such as painting or poetry.
He's also been asked whether using an MRI to study an art form takes away from the mystique with which it's typically regarded.
"Although there’s a tendency to want to very much romanticize artistic creation, kind of put it on the level of magic or something mystical-- while there may be mystical and magical aspects to it, they are products of brain function," Limb says. "And without making that sound mundane, I think that what we’ve done is try to address the fact that, well, it might be ordinary processes within the brain that are giving rise to these extraordinary musical achievements. To me it makes it in a way more appealing than to just leave it in the kind of abstract realm of something mystical."
Limb adds, "And on the other hand, I think music is so mathematical that when we start to put all these things together-- you know the logic and structure of music, the freedom of jazz-- and combine that with the fact that they’re all really products of the human brain, there is sort of a logical correlation that, well, if it’s a product of the brain, we should use tools to study the brain to assess something, even something that’s as seemingly random as jazz."
The study, published in the February 27 issue of PLoS ONE, was funded by the NIDCD.