Charles J. Limb could have been a professional jazz saxophonist. He grew up in a musical family and showed early signs of talent. He idolized John Coltrane and, as a student at Harvard University, directed a jazz band. Although he ultimately went to medical school, he chose his specialty (otolaryngology) in part because of his musical interest. As a hearing specialist and surgeon at Johns Hopkins Hospital, he performed cochlear implants in patients to restore hearing and enable the deaf to appreciate music. His sensibility and passion as an artist continue to inform his research. At least half of his research efforts during the past decade or so have focused on regions of the brain activated during moments of deep creativity. As he puts it, he wants to understand what went on in Coltrane's head when he performed brilliant improv on his sax night after night.
Limb, now a professor at the University of California, San Francisco, and National Institutes of Health neurologist Allen R. Braun developed a method for studying the brains of highly skilled jazz musicians while they are creating music. Subjects play on a nonmagnetic keyboard as they lie in a functional magnetic resonance imaging (fMRI) machine that takes pictures of their brain. Then the scientists compare neural activity during improvisation with what happens when playing a memorized piece. Limb can also interact with the musician in the scanner by playing on an external keyboard—or, as musicians put it, exchanging riffs.
Excerpts from an interview with Limb when he was at Johns Hopkins follow.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Why should scientists study creativity?
While I think creativity is amazing, I don't put it on a pedestal. I view it as a very normal biological process that some people are able to take to extremely profound levels but that fundamentally is a basic requirement of human civilization and how we advance. It infiltrates every aspect of human life. I don't know that there's an attribute that is more responsible for how we've evolved as a species than creativity.
From a scientific perspective: if it's a biological behavior, if humans are creative beings, we really ought to study it like you study any other complex biological behavior. Furthermore, because it does seem to be important, not just for the arts but for life, it's probably something we should understand better.
Why is improvisation an ideal activity for studying creativity?
There are a lot of forms of creativity. For scientific study, what you really need is the behavior that is a prototypical creative act, realizing that it doesn't represent all creative behavior. Writing a novel is a creative act, but it's hard to do that in an fMRI scanner, and something that takes a year or so to do is hard to study. Musical improvisation is spontaneous. The timescale is relatively concise, meaning that every time you do it, you can constrain it to a time frame quite reasonably and expect artistically relevant results. That's a natural task for a musician. So the timescale is natural for a scientific experiment.
What kinds of challenges did you face in trying to summon creativity on demand? Musicians don't usually find a muse in a science lab.
The musicians were a self-selected bunch. I didn't coerce them to participate. They were all into the idea. The experience is foreign for the first minute or two, and then it becomes surprisingly comfortable. You're in a tube, and it's dark, and you have only headphones—it is almost like a sensory deprivation chamber where the only thing you are doing is playing piano. It's really a strange environment for playing piano, but there's not a lot to distract you. In fact, I think the music is very comforting in that setting because it's the one normal thing about the setting. The sound quality of the piano we used isn't the best. It's noisy as heck in that room. But none of the musicians complained, and they were able to play pretty well. Sometimes musicians felt embarrassed that they weren't able to play the way they usually play, but from my perspective they played very well.
Tell us about the keyboard you used in your experiments and how you adapted it to work with fMRI.
The main issues to do this are ergonomic and magnetic. You have to have a keyboard that works when you are in a narrow tube, on your back. I went into the scanner myself many times and thought about what would be the best way to make this work out. We decided the piano should be on your lap, with your hands at a natural angle in front of you, but your eyes—because you are lying down—could not be looking down. We used mirrors, so you look up at one mirror that points to another mirror that is pointed at the keyboard. In the end, you are looking at your hands even though you are looking straight ahead.
The dimension of the tube is such that we could have only 35 keys. I wanted to make them full size so the players would feel relatively natural. I was working with an engineer who designs MRI-compatible devices, and he and I shipped this device across the country probably 10 times to tweak it. It was a two-year process. What we had to design was a MIDI keyboard—for musical instrument digital interface—so the piano makes no noise. Every time you press a note, it sends a digital message to a computer saying a certain note was pressed. I used a program called Logic Pro, which has a piano emulator. When you press a certain note, the computer program plays the note back through headphones. When you're doing it, it feels very much like you're playing a piano naturally.
What happens neurologically to the brain during creativity?
As far as my studies have revealed, creativity is a whole-brain activity. When you're doing something that's creative, you're engaging all aspects of your brain. During improvisation, the prefrontal cortex of the brain undergoes an interesting shift in activity, in which a broad area called the lateral prefrontal region shuts down, essentially so you have a significant inhibition of your prefrontal cortex. These areas are involved in conscious self-monitoring, self-inhibition, and evaluation of the rightness and wrongness of actions you're about to implement. In the meantime, we saw another area of the prefrontal cortex—the medial prefrontal cortex—turn on. This is the focal area of the brain that's involved in self-expression and autobiographical narrative. It's part of what is known as a default network. It has to do with sense of self.
What implications does your work have for, say, education?
If we can understand what actually changes in the brain to perhaps reduce conscious self-monitoring—what a lot of expert musicians are doing and what amateur musicians are unable to do—that's a pretty interesting target for someone to consider when trying to learn to become an improviser. I think that has implications for describing what gives rise to excellent improvisation and what experts do naturally. How a teacher can take that and utilize it in a lesson is another thing entirely, but I think there's food for thought.
A number of researchers are investigating creativity right now.
Why do you think this convergence of interest is taking place?
We have some new methods of analyzing brain activity and brain function that are allowing us to ask questions that were probably off-limits for scientists. And I think that says a lot about the way scientists are in general. Scientists are, for the most part, a pretty conservative bunch. They're not the kinds that want to answer the riskiest questions in terms of art. There are too many variables, it's hard to explain, and there's not a lot of grant funding. It's not disease-based, etcetera. Now we are seeing that, okay, these are legitimate questions to ask, and we have legitimate methods to try to answer the questions. We need to learn how creativity affects the brain and how to implement creativity in educational systems, how to encourage children to be creative.
How do you respond to skeptics and critics who call fMRI research high-tech phrenology?
That's an interesting criticism. There's a big difference between saying that the scalp is shaped a certain way and saying that an area of the brain is physiologically active. What we're really trying to do is take a glimpse into an artist's brain while he is doing something that is unique. Keep in mind the method we use for this—fMRI—is a very, very inferential method. It is completely imprecise on so many levels, and at best you are inferring a pattern of activity that is associated with a pattern of behavior. Every method has its intrinsic limits, and that's how it should be. And in the end, what you want or hope for is that a lot of different methods, not just fMRI, are applied to the same question so that you can see converging data.
There is a reason why we are using fMRI, however. It shows us a lot of things that we've never been able to actually see before, which is human behavior in its most complex forms happening in real time. But I'm a very big critic of anyone who thinks fMRI holds the answer to everything. Having used it, I know it doesn't. On the other hand, that doesn't mean that we shouldn't extract what we can. I mean, it's a cool method.
What are the implications of your creativity research for your work as a surgeon and for cochlear implants?
In truth, the reason why I do what I do is because I love music. That is why I wanted to become a hearing specialist. That led me to treat surgical disorders of hearing primarily. Cochlear implantation is probably the best treatment that has ever existed for a profound sensory impairment, meaning that there is no other sense that can be restored right now like hearing can be with a cochlear implant. These things are amazing technologically. Yet they're also very limited. What they are amazing at is producing language for people who have had intact hearing for most of their lives or for people who are born deaf and gain hearing through implants.
But music is another piece entirely. Most people who have a cochlear implant just cannot hear music well. A large portion of my research goes toward trying to understand the limitations of music perception in deaf people who are hearing with a cochlear implant. And I am hoping to try to improve that. So that is a large part of what I study as well.
For me, the two parts of my work are motivated by the same idea of bringing the sublime to the deaf. The idea of going from deaf to Beethoven's Symphony no. 9 is pretty remarkable. I would love to be able to take somebody there.
Keys to creativity may emerge from imaging musicians' brains. Credit: Charles J. Limb
What's next in your creativity research?
The “trading fours” research, in which I exchange riffs with a musician in the scanner, is still ongoing, as are the studies of freestyle rappers, which I believe represents the first-ever neuroscientific study of hip-hop.
The next real direction I've headed into has to do with trying to clarify our study of reward mechanisms in the brain and their relation to creativity. Why is it that we like to be creative? Why is it that we like to perceive creativity? And what happens when somebody is improvising in terms of pleasure or reward centers? Where is the gratification neurologically, and how does that change according to the emotional content of the music?
I've always wondered: Why do we love sad music? Why does it make us feel better and not worse? It's a funny inversion that takes place in the brain. Whereas we try to avoid sadness in life, in art, and especially in music, we almost gravitate toward it. By and large, the effect is very positive. Improvisation causes a similar response: When you're spontaneously creating music that is sad, what are you getting? Are you getting joy? Pleasure? What's the basis of the reward? That's one of the directions I'm heading.
What's your best answer to how Coltrane continually improvised masterpiece after masterpiece on his saxophone?
My best answer, honestly, is that he practiced. He was an obsessive—he practiced obsessively, even after a gig. He would play a gig and then go back to his hotel room and practice. And he was, I think, obsessed with an idea that was well beyond a performance, well beyond what a critic or a listener thought. He was really after some sort of musical perfection: the ability to have an idea that he had never had before, have that idea be profound and, at the same time, be able to execute that idea. That's a remarkable trio of goals to have right there. I think he knew that the only way he would even come close was to keep that horn in his mouth.