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TEDxMidAtlantic

Charles Limb: Your brain on improv

Filmed:

Musician and researcher Charles Limb wondered how the brain works during musical improvisation -- so he put jazz musicians and rappers in an fMRI to find out. What he and his team found has deep implications for our understanding of creativity of all kinds. (Filmed at TEDxMidAtlantic.)

- Researcher
Charles Limb is a doctor and a musician who researches the way musical creativity works in the brain. Full bio

So I am a surgeon who studies creativity,
00:15
and I have never had a patient tell me
00:18
that "I really want you to be creative during surgery,"
00:21
and so I guess there's a little bit of irony to it.
00:24
I will say though that, after having done surgery a lot,
00:27
it's somewhat similar to playing a musical instrument.
00:30
And for me, this sort of deep and enduring fascination with sound
00:32
is what led me to both be a surgeon
00:35
and also to study the science of sound, particularly music.
00:37
And so I'm going to try to talk to you over the next few minutes
00:39
about my career
00:41
in terms of how I'm able to actually try to study music
00:43
and really try to grapple with all these questions
00:45
of how the brain is able to be creative.
00:47
I've done most of this work at Johns Hopkins University,
00:50
but also at the National Institute of Health where I was previously.
00:52
I'm going to go over some science experiments
00:54
and try to cover three musical experiments.
00:56
I'm going to start off by playing a video for you.
00:58
And this video is a video of Keith Jarrett, who's a well-known jazz improviser
01:00
and probably the most well-known, iconic example
01:03
of someone who takes improvisation to a really higher level.
01:06
And he'll improvise entire concerts
01:08
off the top of his head,
01:10
and he'll never play it exactly the same way again,
01:12
and so, as a form of intense creativity,
01:14
I think this is a great example.
01:16
And so why don't we go and click the video.
01:18
(Music)
01:21
It's really a remarkable, awesome thing that happens there.
02:17
I've always -- just as a listener, as just a fan --
02:20
I listen to that, and I'm just astounded.
02:22
I think -- how can this possibly be?
02:24
How can the brain generate that much information,
02:26
that much music, spontaneously?
02:28
And so I set out with this concept, scientifically,
02:30
that artistic creativity, it's magical, but it's not magic,
02:33
meaning that it's a product of the brain.
02:36
There's not too many brain-dead people creating art.
02:38
And so with this notion that artistic creativity
02:41
is in fact a neurologic product,
02:43
I took this thesis that we could study it
02:45
just like we study any other complex neurologic process.
02:48
And I think there's some sub-questions there that I put there.
02:51
Is it truly possible to study creativity scientifically?
02:53
And I think that's a good question.
02:55
And I'll tell you that most scientific studies of music,
02:57
they're very dense,
03:00
and when you actually go through them, it's very hard to recognize the music in it.
03:02
In fact, they seem to be very unmusical entirely
03:05
and to miss the whole point of the music.
03:07
And so it brings the second question:
03:09
Why should scientists study creativity?
03:11
Maybe we're not the right people to do it.
03:13
Well it may be,
03:15
but I will say that, from a scientific perspective --
03:17
we talked a lot about innovation today --
03:19
the science of innovation,
03:21
how much we understand about how the brain is able to innovate
03:23
is in its infancy,
03:25
and truly, we know very little about how we are able to be creative.
03:27
And so I think that we're going to see
03:30
over the next 10, 20, 30 years
03:32
a real science of creativity that's burgeoning and is going to flourish.
03:34
Because we now have new methods that can enable us
03:37
to take this process of something like this,
03:39
complex jazz improvisation, and study it rigorously.
03:41
And so it gets down to the brain.
03:43
And so all of us have this remarkable brain,
03:45
which is poorly understood to say the least.
03:47
I think that neuroscientists
03:50
have many more questions than answers,
03:52
and I myself, I'm not going to give you many answers today,
03:54
just ask a lot of questions.
03:56
And fundamentally that's what I do in my lab.
03:58
I ask questions about what is this brain doing to enable us to do this.
04:00
This is the main method that I use. This is called functional MRI.
04:02
If you've been in an MRI scanner, it's very much the same,
04:05
but this one is outfitted in a special way
04:08
to not just take pictures of your brain,
04:10
but to also take pictures of active areas of the brain.
04:12
Now the way that's done is by the following.
04:15
There's something called BOLD imaging,
04:17
which is Blood Oxygen Level Dependent imaging.
04:19
Now when you're in an fMRI scanner,
04:21
you're in a big magnet
04:23
that's aligning your molecules in certain areas.
04:25
When an area of the brain is active, meaning a neural area is active,
04:27
it gets blood flow shunted to that area.
04:30
That blood flow causes an increase
04:33
in local blood to that area
04:35
with a deoxyhemoglobin change in concentration.
04:37
Deoxyhemoglobin can be detected by MRI,
04:40
whereas oxyhemoglobin can't.
04:42
So through this method of inference --
04:44
and we're measuring blood flow, not neural activity --
04:46
we say that an area of the brain that's getting more blood
04:48
was active during a particular task,
04:50
and that's the crux of how fMRI works.
04:52
And it's been used since the '90s
04:54
to study really complex processes.
04:56
Now I'm going to review a study that I did,
04:59
which was jazz in an fMRI scanner.
05:01
And this was done with a colleague of mine, Alan Braun, at the NIH.
05:03
This is a short video of how we did this project.
05:05
(Video) Charles Limb: This is a plastic MIDI piano keyboard
05:08
that we use for the jazz experiments.
05:10
And it's a 35-key keyboard
05:12
that is designed to fit both inside the scanner,
05:14
be magnetically safe,
05:16
have minimal interference
05:18
that would contribute to any artifact
05:20
and have this cushion so that it can rest on the players' legs
05:22
while they're lying down in the scanner, playing on their back.
05:25
And it works like this -- this doesn't actually produce any sound.
05:28
It sends out what's called a MIDI signal --
05:31
or a Musical Instrument Digital Interface --
05:33
through these wires into the box and then the computer,
05:35
which then trigger high-quality piano samples like this.
05:38
(Music)
05:41
(Music)
05:47
CL: Okay, so it works.
06:09
And so through this piano keyboard,
06:11
we now have the means to take a musical process and study it.
06:13
So what do you do now that you have this cool piano keyboard?
06:15
You can't just sort of -- "It's great we've got this keyboard."
06:18
We actually have to come up with a scientific experiment.
06:20
And so the experiment really rests on the following:
06:22
What happens in the brain during something that's memorized and over-learned,
06:26
and what happens in the brain during something
06:29
that is spontaneously generated, or improvised,
06:31
in a way that's matched motorically
06:33
and in terms of lower-level sensory motor features?
06:35
And so, I have here what we call the "paradigms."
06:38
There's a scale paradigm, which is just playing a scale up and down, memorized.
06:41
And then there's improvising on a scale --
06:44
quarter notes, metronome, right hand --
06:46
scientifically very safe,
06:48
but musically really boring.
06:50
And then there's the bottom one, which is called the jazz paradigm.
06:52
And so what we did was we brought professional jazz players to the NIH,
06:54
and we had them memorize this piece of music on the left, the lower-left --
06:56
which is what you heard me playing --
06:59
and then we had them improvise to the same exact chord changes.
07:01
And if you can hit that lower-right sound icon,
07:04
that's an example of what was recorded in the scanner.
07:06
(Music)
07:08
So in the end, it's not the most natural environment,
07:36
but they're able to play real music.
07:38
And I've listened to that solo 200 times,
07:40
and I still like it.
07:42
And the musicians, they were comfortable in the end.
07:44
And so we first measured the number of notes.
07:46
Were they in fact just playing a lot more notes when they were improvising?
07:48
That was not what was going on.
07:50
And then we looked at the brain activity.
07:52
I'm going to try to condense this for you.
07:54
These are contrast maps that are showing subtractions
07:56
between what changes when you're improvising
07:59
versus when you're doing something memorized.
08:01
In red is an area that active in the prefrontal cortex,
08:03
the frontal lobe of the brain,
08:05
and in blue is this area that was deactivated.
08:07
And so we had this focal area called the medial prefrontal cortex
08:09
that went way up in activity.
08:11
We had this broad patch of area called the lateral prefrontal cortex
08:13
that went way down in activity, and I'll summarize that for you here.
08:16
Now these are multifunctional areas of the brain.
08:19
As I like to say, these are not the "jazz areas" of the brain.
08:21
They do a whole host of things
08:24
that have to do with self-reflection,
08:26
introspection, working memory and so forth.
08:28
Really, consciousness is seated in the frontal lobe.
08:30
But we have this combination
08:33
of an area that's thought to be involved in self-monitoring, turning off,
08:35
and this area that's thought to be autobiographical,
08:38
or self-expressive, turning on.
08:40
And we think, at least in this preliminary --
08:42
it's one study; it's probably wrong,
08:44
but it's one study --
08:46
we think that at least a reasonable hypothesis
08:48
is that, to be creative,
08:51
you have to have this weird dissociation in your frontal lobe.
08:53
One area turns on, and a big area shuts off,
08:55
so that you're not inhibited, so that you're willing to make mistakes,
08:57
so that you're not constantly shutting down
09:00
all of these new generative impulses.
09:02
Now a lot of people know that music is not always a solo activity --
09:05
sometimes it's done communicatively.
09:08
And so the next question was:
09:10
What happens when musicians are trading back and forth,
09:12
something called "trading fours,"
09:14
which is something they do normally in a jazz experiment?
09:16
So this is a twelve-bar blues.
09:18
And I've broken it down into four-bar groups here,
09:20
so you would know how you would trade.
09:22
Now what we did was we brought a musician into the scanner -- same way --
09:24
had them memorize this melody
09:26
and then had another musician out in the control room
09:28
trading back and forth interactively.
09:30
So this is a musician, Mike Pope,
09:33
one of the world's best bassists and a fantastic piano player.
09:35
So he's now playing the piece
09:43
that we just saw
09:45
just a little better than I wrote it.
09:47
(Video) CL: Mike, come on in. Mike Pope: May the force be with you.
09:49
Nurse: Nothing's in your pockets, right Mike?
09:51
MP: Nope. Nothing's in my pockets. Nurse: Okay.
09:53
CL: You have to have the right attitude to agree to it.
10:05
(Laughter)
10:07
It's kind of fun actually.
10:09
And so now we're playing back and forth.
10:11
He's in there. You can see his legs up there.
10:14
And then I'm in the control room here, playing back and forth.
10:18
(Music)
10:21
(Video) Mike Pope: This is a pretty good representation
10:33
of what it's like.
10:36
And it's good that it's not too quick.
10:38
The fact that we do it over and over again
10:40
lets you acclimate to your surroundings.
10:42
So the hardest thing for me was the kinesthetic thing,
10:46
of looking at my hands
10:49
through two mirrors,
10:51
laying on my back
10:53
and not able to move at all except for my hand.
10:55
That was challenging.
10:57
But again,
10:59
there were moments, for sure,
11:01
there were moments
11:04
of real, honest-to-God musical interplay, for sure.
11:06
CL: At this point, I'll take a few moments.
11:10
And so what you're seeing here --
11:12
and I'm doing a cardinal sin in science,
11:14
which is to show you preliminary data.
11:16
This is one subject's data.
11:18
This is, in fact, Mike Pope's data.
11:20
So what am I showing you here?
11:22
When he was trading fours with me, improvising versus memorized,
11:24
his language areas lit up, his Broca's area,
11:27
which is inferior frontal gyrus on the left.
11:30
He actually had it also homologous on the right.
11:32
This is an area thought to be involved in expressive communication.
11:34
This whole notion that music is a language --
11:37
well maybe there's a neurologic basis to it in fact after all,
11:39
and we can see it when two musicians are having a musical conversation.
11:42
And so we've done this actually on eight subjects now,
11:45
and we're just getting all the data together,
11:47
so hopefully we'll have something to say about it meaningfully.
11:49
Now when I think about improvisation and the language, well what's next?
11:51
Rap, of course, rap --
11:54
free-style.
11:56
And so I've always been fascinated by free-style.
11:58
And let's go ahead and play this video here.
12:00
(Video) Mos Def: ♫ ... brown skin I be, standing five-ten I be ♫
12:02
♫ Rockin' it when I be, in your vicinity ♫
12:04
♫ Whole-style synergy, recognize symmetry ♫
12:07
♫ Go and try to injure me, broke 'em down chemically ♫
12:09
♫ Ain't the number 10 MC, talk about how been I be ♫
12:12
♫ Styled it like Kennedy, late like a 10 to three ♫
12:14
♫ When I say when I be, girls say bend that key cut ♫
12:17
CL: And so there's a lot of analogy
12:20
between what takes place in free-style rap and jazz.
12:22
There are, in fact, a lot of correlations between the two forms of music
12:24
I think in different time periods.
12:26
In a lot a ways, rap serves the same social function
12:28
that jazz used to serve.
12:30
So how do you study rap scientifically?
12:32
And my colleagues kind of think I'm crazy,
12:34
but I think it's very viable.
12:36
And so this is what you do: you have a free-style artist
12:38
come in and memorize a rap that you write for them,
12:40
that they've never heard before,
12:42
and then you have them free-style.
12:44
So I told my lab members that I would rap for TED,
12:46
and they said, "No, you won't."
12:48
And then I thought --
12:50
(Applause)
12:52
But here's the thing.
12:58
With this big screen, you can all rap with me. Okay?
13:00
So what we had them do
13:03
was memorize this lower-left sound icon, please.
13:05
This is the control condition. This is what they memorized.
13:07
Computer: ♫ Memory, thump. ♫
13:10
CL: ♫ Thump of the beat in a known repeat ♫
13:12
♫ Rhythm and rhyme, they make me complete ♫
13:15
♫ The climb is sublime when I'm on the mic ♫
13:18
♫ Spittin' rhymes that hit you like a lightning strike ♫
13:20
♫ I search for the truth in this eternal quest ♫
13:23
♫ My passion's not fashion, you can see how I'm dressed ♫
13:25
♫ Psychopathic words in my head appear ♫
13:28
♫ Whisper these lyrics only I can hear ♫
13:31
♫ The art of discovering and that which is hovering ♫
13:34
♫ Inside the mind of those unconfined ♫
13:36
♫ All of these words keep pouring out like rain ♫
13:39
♫ I need a mad scientist to check my brain ♫
13:42
(Applause)
13:45
I guarantee you that will never happen again.
13:54
(Laughter)
13:57
So now, what's great about these free-stylers,
13:59
they will get cued different words.
14:01
They don't know what's coming, but they'll hear something off the cuff.
14:03
Go ahead and hit that right sound icon.
14:05
They are going to be cued these three square words: "like," "not" and "head."
14:07
He doesn't know what's coming.
14:10
Free-styler: ♫ I'm like some kind of [unclear] ♫
14:12
♫ [unclear] extraterrestrial, celestial scene ♫
14:14
♫ Back in the days, I used to sit in pyramids and meditate ♫
14:17
♫ With two microphones hovering over my head ♫
14:20
♫ See if I could still listen, spittin' off the sound ♫
14:23
♫ See what you grinning ♫
14:26
♫ I teach the children in the back of the classroom ♫
14:28
♫ About the message of apocalyptical ♫
14:30
♫ Not really though, 'cause I've got to keep it simple ♫
14:33
♫ [unclear] instrumental ♫
14:36
♫ Detrimental playing Super Mario ♫
14:38
♫ [unclear] boxes [unclear] hip hop ♫
14:41
CL: So again, it's an incredible thing that's taking place.
14:45
It's doing something that, neurologically, is remarkable.
14:47
Whether or not you like the music is irrelevant.
14:49
Creatively speaking, it's just a phenomenal thing.
14:51
This is a short video of how we actually do this in a scanner.
14:53
(Laughter)
14:56
(Video) CL: We're here with Emmanuel.
14:59
CL: That was recorded in the scanner, by the way.
15:01
(Video) CL: That's Emmanuel in the scanner.
15:03
He's just memorized a rhyme for us.
15:06
Emmanuel: ♫ Top of the beat with no repeat ♫
15:12
♫ Rhythm and rhyme make me complete ♫
15:15
♫ Climb is sublime when I'm on the mic ♫
15:18
♫ Spittin' rhymes that'll hit you like a lightning strike ♫
15:21
♫ I search for the truth in this eternal quest ♫
15:23
♫ I'm passing on fashion; you can see how I'm dressed ♫
15:26
CL: Okay. So I'm going to stop that there. So what do we see in his brain?
15:29
Well, this is actually four rappers' brains.
15:32
And what we see, we do see language areas lighting up,
15:34
but then -- eyes closed --
15:36
when you are free-styling versus memorizing,
15:38
you've got major visual areas lighting up.
15:41
You've got major cerebellar activity, which is involved in motor coordination.
15:43
You have heightened brain activity when you're doing a comparable task,
15:46
when that one task is creative and the other task is memorized.
15:49
It's very preliminary, but I think it's kind of cool.
15:53
So just to conclude, we've got a lot of questions to ask,
15:55
and like I said, we'll ask questions here, not answer them.
15:58
But we want to get at the root of what is creative genius, neurologically,
16:01
and I think, with these methods, we're getting close to being there.
16:04
And I think hopefully in the next 10, 20 years
16:07
you'll actually see real, meaningful studies
16:09
that say science has to catch up to art,
16:11
and maybe we're starting now to get there.
16:15
And so I want to thank you for your time. I appreciate it.
16:17
(Applause)
16:19

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About the Speaker:

Charles Limb - Researcher
Charles Limb is a doctor and a musician who researches the way musical creativity works in the brain.

Why you should listen

Charles Limb is the Francis A. Sooy, MD Professor and Chief of Otology/Neurotology and Skull Base Surgery at the University of California, San Francisco, and he's a Faculty Member at the Peabody Conservatory of Music. He combines his two passions to study the way the brain creates and perceives music. He's a hearing specialist and surgeon at Johns Hopkins who performs cochlear implantations on patients who have lost their hearing. And he plays sax, piano and bass.

In search of a better understanding of how the mind perceives complex auditory stimuli such as music, he's been working with Allen Braun to look at the brains of improvising musicians and study what parts of the brain are involved in the kind of deep creativity that happens when a musician is really in the groove.

Read our Q&A about hip-hop studies with Charles Limb on the TED Blog >>

Plus our quick catchup Q&A at TEDMED 2011 -- including his top 5 songs of all time >>

Read the 2014 paper "Neural Substrates of Interactive Musical Improvisation: An fMRI Study of ‘Trading Fours’ in Jazz" >>

More profile about the speaker
Charles Limb | Speaker | TED.com