Ep84 "Why do brains love music?" - podcast episode cover

Ep84 "Why do brains love music?"

Dec 09, 202447 minEp. 84
--:--
--:--
Listen in podcast apps:

Summary

David Eagleman and Daniel Levitin explore the neuroscience of music, discussing how the brain processes music, its emotional impact, therapeutic uses for conditions like dementia and Parkinson's, and the role of music in human evolution. They also discuss the future of AI in music and the importance of individual musical preferences.

Episode description

How can we understand music's effect on human brains? Is music universal or does it rely on your experiences? How is music similar to a language? Can music be leveraged to help anxiety, dementia, or Parkinson's disease? What does any of this have to do with Stevie Wonder on the high hat, or the relationship between music and color? Join Eagleman with guest Daniel Levitin -- neuroscientist, musician, and author of This Is Your Brain on Music and I Heard There Was A Secret Chord.

Transcript

Speaker 1

How can we understand what music is about from the point of view of neuroscience. Can music be leveraged to help with anxiety disorders, or with dementia or with Parkinson's disease? Is music universal or does it have to do with what you have absorbed in your lifetime? How is music like a language but one with very particular structure and therefore high predictability. And what does this have to do with Stevie Wonder on the High Hat or the relationship

between music and color. Welcome to Inner Cosmos with me David Eagleman. I'm a neuroscientist and an author at Stanford and in these episodes we sail deeply into our three pound universe to understand why and how our lives look the way they do. Today's episode is about music and the brain, and this is a topic that has been requested by several different listeners, so I prioritized making this episode. Music.

I suspect is a popular topic because music can be so emotive for us and so catchy and so meaningful. My father, for example, who was the quintessential tough guy when he would listen to Mozart or Brahms or Beethoven, he would have tears streaming down his cheeks. And as a child, I didn't have much understanding of classical music, but that really caused me to wonder, what is going on here? Why does this music wafting out of the radio evoke such strong emotions and perhaps such deep memories

in my father? And as I got older and became a neuroscientist, I wondered, is there something you unique in the structure of the human brain that ties music so closely with our emotional experiences? So I decided to do an episode on this today, and I realized there was no one better to ring up than my friend and colleague, Daniel Leviton. He's the founding Dean of Arts and Humanities at Minerva University in San Francisco and a professor emeritus

of psychology and neuroscience at McGill University in Montreal. You may know Dan because he wrote a book called This Is Your Brain on music, the Science of a Human Obsession, which became a big New York Times bestseller, and he's also written four other best selling books, including his latest, which is called I Heard There Was a Secret Chord. Music as Medicine. Now, as you may suspect. Dan is

also a very talented musician. He composes music and he's worked on albums by Blue Oyster Cult and Chris Isaac and Joe Satriani, among many others. He does this as an advisory producer a recording engineer. So given his expertise, I wanted to sit down with Dan to get his take on music and the brain. Okay, Dan, what goes on in the brain when you listen to music?

Speaker 2

Yeah, well, it really is quite fascinating. So it begins

with the sound waves impinging on your ear drums. They wiggle in and out, and all the information you have about the auditory world comes from molecules vibrating in some medium, in our case air, it could be underwater, and then your ear drums just wiggle in and out, and then your brain has to take that wiggling in and out and extract from it all the different sounds a bird chirping, a leaf blower going, the oboe in the symphony as opposed to the French horns in a crowded room, the

conversation you're trying to listen to in front of you, as well as that when you're eavesdropping in. It has to separate all that out. And the way it does that is that your brain has special processing circuits. I was going to use the word designed, but of course they weren't designed, but evolved to do different distinct functions. One circuit processes the loudness is anything louder, is it getting softer? And it follows that loudness trajectory, which can be an important cue as.

Speaker 3

To what's going on. Pitch duration.

Speaker 2

The pitches get in a separate circuit, bound into a representation of melody and harmony, the durations into a representation of rhythm and meter, the loudness into accent structure, timbre, which is the quality that distinguishes your voice from my voice when we're saying the same thing, or a trumpet from a piano when they're playing the same note. That's a combination of spectral temporal information, in other words, pitch

and time and loudness. It all comes together later in the brain and you just hear that song where later in the brain is maybe forty milliseconds. It happens so seamlessly that it just sounds like we're hearing the song, but we're not. Our brain is hearing the pitch, the rhythm, the loudness, the timber, and our evidence, David, that this

happens is not just from neuroimaging, but from patients. We see patients with focal brain damage who suddenly lose their perception of pitch, but they retain rhythm or vice versa.

Speaker 1

Okay, so it's this terrifically complicated computational process. So why does it end up feeling so emotional for us?

Speaker 3

Well?

Speaker 2

So I think there are both neurobiological reasons and evolutionary reasons that are connected. Of course, the simple answer is it's emotional for us because emotion circuits in the brain are involved in music processing. And by that I mean, among others, the well known reward center that you and I have talked about in our own classes over the years and with one another, the limbic system, the structures like the nucleus of Cumban's, the amygdala, the ventral tegmental area.

This is the emotional core part of the reptilian brain that you know motivates us to move out of the way of some approaching danger or to signal pleasure when we're hungry and we finally get a taste of something sweet. Music activates that same center, and in fact, it was my lab that was the first to show that our brain produces dopamine in response to music listening, and later we showed that our brain produces its own endogenous opioids in response to music listening, all part of that well

known pleasure network. Now, of course, that raises the question why why is you know, over ever solutionary timescals did music hit that emotional center and hear The answer is by fer Kate. One is that the well known startle response. You hear a sudden, loud noise and you jump. That's evolutionarily adaptive because you know, you know, even lizards, snakes, reptiles have to move out of the way of something

that might step on them or smash them. And that startle response in humans goes directly from the inner ear to the cerebellum and the brain stem. Before we even figure out what the sound is, we startle and that's connected to emotion centers. And so music, because it's an auditory stimulus, is hardwired to movement and to emotion.

Speaker 1

So what happens in the brain when you play an instrument.

Speaker 2

Playing instrument is one of the most neuroprotective things we can do. Glistening activates every area of the brain that we so far mapped, as does playing an instrument. But the added advantage of playing an instrument is that it's active rather than passive, and it involves prediction centers in the prefrontal cortex, particularly broad An area forty seven, which

is a pattern detector. You know, Venode, Menna and I at Stanford for thirty years have been looking at this little sliver of tissue on either side of your between your top of your ears and your eyeballs broad and forty seven, and Michael Patritus and I at mcgil have also looked at it as that part of the human brain that primates lack that allows us to process temporal patterns, either in vision, touch or sound. And so in playing an instrument, you've got to plan what you want it

to sound like. Hopefully you've got some idea of what you want to come out, and then you've got to use a feedback loop to listen to what came out and see how well it matches with what you intended and that adjust or not. And Broaden forty seven is a part of that, as well as other prefrontal areas and temporal areas.

Speaker 1

Before we move on some other questions, I want to ask what got you into this intersection between music and the brain.

Speaker 3

It wasn't intentional.

Speaker 2

I had dropped out of college after my sophomore year to play in a series of bands, and that led to me becoming a staff producer at Columbia Records in the eighties and in the nineties, when the music business seemed to be imploding, a bunch of us who had entered the business around the same time, figured we needed a plan B, that this may not be a sustainable career, and so I went back and finished my bachelor's degree at Stanford. I just worked in every lab that would

have me. Then I went to graduate school and Oregon in order to work with Doug Hintsman and Helen Neville a language specialist, and of course Mike Posner on neuroimaging. And I was just doing all these things in parallel and loving it. I mentioned all these names because they were very important mentors to me, each of them. And in the third year of my graduate program, Posner, who was my principal advisor, said, you know you're gonna have to specialize. What do you want to do when you

grow up. I said, well, I really love all of this. I love psycholinguistics, I love memory, I love decision making, and I had worked in all those areas. And he said, well, you know, you have this background as a musician, and there's a lot of competition for jobs in those other fields. There's this emerging field of psychology of music with a handful of people in it. Maybe if you go into that field, there'll be a lot of low hanging fruit, as it were, a lot of studies that have obviously

need to be done that haven't been done yet. And in addition, although nobody's going to advertise for a music psychology faculty member, all those other things apply to music psychology, decision making, how do we decide what we want to listen to? Cyclel linguistics, psychology of lyrics and music, individual differences in musical taste, memory for music. So it was Mike who said preciently that I should brand myself as a music psychologist. Of course, back in those days, there

were no neuroscience departments, there were no neuroscience programs. You could not study neuroscience as you and I know it. And I'll make a distinction for our listeners between like molecular neuroscience, which was done in biology departments where you only look at a single neuron and you've never even considered what a thought might be and what we call you.

And I work in the area systems neuroscience, where we're looking at the big ideas andions of neurons communicate with other millions in neurons.

Speaker 1

I know that you feel like that the music psychology world was not particularly good let's say twenty years ago, so give us a sense of what it was like at that point when people thought about I'm going to study the psychology music and what it's like now and what's changed.

Speaker 2

And there were a bunch of other people who hadn't studied cognitive psychology but fancy themselves music psychologists, and they did a bunch of bad studies, the poster child for that being the Mozart effect study, which purported to show that listening to Mozart for twenty minutes would make you smarter. And there have now been literally one hundred studies that shows that that was just bullshit. It was a poorly controlled study, It was done by people who had no

experience in human experimental design. They stepped outside their lane, and so there was a lot of garbage work being done. What's different now is that we've had twenty years of people applying to graduate school who knew they wanted to study music psychology. Some of them went into music psychologists' labs like mine. Others did what I did. They went into the lab of a memory person or an attention or brain imaging person and just used that interest in music to design studies.

Speaker 1

And so what sort of things have come out in the last twenty years. Part of this has to do with the advent of neuroimaging, right.

Speaker 2

Well, that really, that really is what kicked it off, because, as you know, David, the study of emotion was rather unseemly. I think it began with the foundation of the first psychology labs in the world by Vuntenfeckner in Europe. Of course, William James was always more interested in the esthetics and artistics side, but it was the behaviorist movement of the fifties led by BF Skinner, that if something wasn't deservable

and replicable, it wasn't worth study. And so emotions just seemed too squishy, and music as the language of emotion seemed like the squishiest of all. What happened with the first studies of neuroimaging, which Mike Posner was part of nineteen ninety eight ninety nine. We were able to actually see pictures of the brain caught in the act of thinking and remembering and imagining, and that gave it a

biological basis reality. You could replicate brain imaging experiments, and so first the study of emotion, and then shortly followed by the study of music with the first neu imaging studies of music in the early two thousands, that put it back on the table as something that was worthy of study and could be done in a rigorous fashion.

Speaker 1

So your latest book, I heard, There was a Secret Chord, looks at this issue of muse musick as medicine. So tell us about that.

Speaker 2

That's something that I think most of us have experienced intuitively, certainly, it goes back tens of thousands of years using music to treat injury and disease to shamans and faith healers and indigenous tribes. And it was really in the last ten years. I would say that the idea that music had an evidence base for treating injury disease promoting wellness, helping with mental disorders like depression, post traumatic stress disorder, anxiety.

There's been eight thousand papers in the last two years alone in peer review journals on medical applications of music, and so about five years ago I became involved with the National Institutes of Health and the White House Science Office, leading various expert panels to figure out what do we really know and what do we don't know and what remains to be done. That led to a call for proposals. The NIH put forty million into music and medicine research

a few years back. So I looked for a book on music and medicine because I wanted to know what the state of the art was, and I couldn't find one. There were a lot of papers, but no books, and so I ended up writing the book I wanted.

Speaker 1

To read and so give us a sense when it comes to something like, let's start with dementia, how would music be useful in the case of something like Alzheimer's.

Speaker 2

Not all dementia is Alzheimer's, of course, and not all memory loss comes from Alzheimer's. But the most straightforward case of somebody with profound memory loss, perhaps due to Alzheimer's, Corsokov's stroke, whatever. They may not recognize where they are, They may not recognize loved ones. They may not even

recognize themselves in the mirror. This is profoundly We've seen patients who will walk by a mirror and think they're talking to someone else, and then they get angry because the person in the mirror appears to be mocking them by gesturing the same way they are, and it causes

one of two reactions. Individuals either turn in on themselves, fold in on unsells because the external world makes no sense and they become somewhat catatonic, or they become angry, agitated, and violent and in that case have to be medicated. They might start beating up on their spouses, not recognizing them. Music follows a kind of principle that computer science talks about, which is first in, last out.

Speaker 3

This is a holder for the old models of computer memory.

Speaker 2

The first thing that goes into the memory is the last thing to come out. And because we've been listening to music in the womb most of us and through our childhoods, those memories the most deeply embedded in the brain and the most resilient and resistant to decay or damage.

And so if we play music from the youth of an Alzheimer's patient, somebody with profound memory loss, play the music from say the ages of twelve to fourteen or sixteen that's preserved in most cases, and it allows them to profoundly reconnect with a part of themselves they had lost.

It eases them, it comforts them, It triggers memories that had been buried, and that kind of therapy or intervention can pull them out of the state they're in and actually have consequences for days or weeks where they come alive again.

Speaker 1

It doesn't cure or help the dementia the cognitive loss exactly, but it triggers memories and pulls them back to state where they've been. And it can also revivify skills that someone has. For example, musicians with profound dementia who get an instrument put in their hand and they go and play again as though they're young.

Speaker 2

It's really extraordinary. And we saw this play out in recent years with Glenn Campbell first and then with Tony Bennett, both of whom had profound memory loss and did not know where they were. When Glenn did his final tour with dementia and in the throes of Alzheimer's. He would sometimes play a song two or three times in a row because they didn't realize he had just played it, or he'd forget what song he was supposed to play. But once the notes, the first few notes happened, he

knew where he was. Say, with Tony Bennett, he could sing for an hour and a half without stopping once the music took over. These are what we cognitive scientists call overlearned. They're not just in memory, but they're in memory with thousands and thousands of traces overlaid on top of one another and their procedural memory. Once your vocal cords and your fingers get going, they kind of take over. Now, to be clear, the memory is not in your fingers,

although it feels that way. If I were to scoop your brain outside your head, your fingers would not keep playing like a chicken with its head cut off. But those pathways are so profoundly deeply embedded that yeah, you can keep going even with Alzheimer's, and it gives the patient a rare act of competence in a world in which they're otherwise incompetent. It gives them agency in the world. This can really affect their mood and their quality of life and way of being in the world.

Speaker 1

Now, one of the things I've talked about on in previous episode is right Bo's law, which is where older memories are more secure, they're burned down more deeply than newer memories. And of course we see this with people with cogno.

Speaker 2

I thought you were going with Bow's law, like the bow on a violin, the earliest violin pieces are the ones that are the most embedded.

Speaker 1

Yeah, nope, Riebo Ribot, Yeah, which is you know, he was the first I think this is actually the first rule in neurology, as in the oldest rule.

Speaker 2

Yeah.

Speaker 1

But anyway, he saw that, you know, things from childhood were remembered by people with let's say dementia, and things they did last week or last month were not remembered, so older members more stable. Now, the reason this is so strange is because nothing else works that way. Institutions, for example, don't remember their older stuff better than they remember their newer stuff. But brain works this way.

Speaker 3

That is true.

Speaker 1

So my question is, I mean, when when it comes to music, presumably most of these great musicians have been playing since they were a little kids, and these particular songs are overlearned, as you mentioned. Is this an expression of simply of Ribo's law, which is that it's an older memory and that's why they're able to do it? Or is there something different about music than if I ask them something about their you know, their their childhood home.

Speaker 3

What a great question.

Speaker 2

Well, there is something different about music to invoke Claude Shannon. It's a highly organized and structured stimulus like language, and so in an information theory perspective, which is Shannon, your ability to predict what will come next in any sequence defines how structured highly structured it is. Even more so than language. Music is highly constrained. So I could say a sentence to you like this, Let's try this, the pizza was too hot to blank? What comes to mind?

Eat yeah or touch yeah? I would not be likely to say the pizza was too hot to sleep. Once I say it, you understand what I meant, and you understand that I use the correct part of speech. I put a verb at the end, But it's an unlikely outcome. Music is even more constrained because there are only twelve notes in our scale, and there are I wouldn't call them laws of music theory, but customs of music theory. And there are rhythmic rules or customs.

Speaker 3

And so once you.

Speaker 2

Get going on a piece of music, its own structure constrains what the possible completions are, making it easier to remember and then easier to recollect, easier to store and easier to retrieve, and then moreover, as its own internal tempo. Once the beat is going, it's carrying you along, whether you're ready to go along with it or not. And so you're going to fill those slots with what needs

to go there or your best approximation for it. And when you look at performing musicians, like typically the ones that work holiday ins on Friday night lounge bands and stuff, they might know two thousand songs where I would use the word no in quotes, they probably don't know every single note and every single rhythm.

Speaker 3

But they can approximate it.

Speaker 2

They can improvise and estimate it so that you don't really notice the difference.

Speaker 1

Well, that's actually a good segue into Parkinson's disease.

Speaker 2

How is music used there? So in all these cases of music is medicine. We're not talking about like a music module in the brain or a music medicine prescription that's straightforward, because music is doing different things in different parts of the brain, different aspects of the music are doing it, and Parkinson's is I'm so glad you brought this up. It's actually the best case for understanding this

differentiation in Parkinson's disease. At some point, most patients will experience difficulty walking movement disorders in general, but walking in particular, and it's because the disease degrade circuits in the basal ganglia that are required to maintain a smooth and steady gait and to orchestrate the movements of one foot has to go after the other and you have to put it down at a certain time where you end up with both feet in the air at the same time,

and that's not good for walking. And the circuits that allow you to walk rely on an internal intrinsic timer in the brain, a clock, and that's what gets degraded. If you listen to music that has the tempo of your natural gait, you have neurons, neuronal clusters that were not damaged that synchronize to that pulse, and then they can act as an external clock that allows you to walk smoothly and continuously.

Speaker 1

What else besides dementia and Parkinson's, where else do we see therapeutic effects?

Speaker 2

Well, I think one of the big ones is an anxiety. Dentists figured this out a long time ago. They play you what's supposed to be relaxing music to reduce your anxiety, which reduces swelling and inflammation.

Speaker 1

And why does that work?

Speaker 2

Some music we find to be relaxing, some we find to be stimulating, some we find to be inspiring. And the difficulty is, there's no one music that will do those things for everybody. In fact, there's no one song everybody likes. There's no one song everybody hates. It's subjective, like your taste for food. You know, why doesn't everybody like Indian food? I love food, Not everybody does. You

have our own taste. It seems as though we have an esthetic module each of us that governs things like our taste and colors and people and tastes and music. And we actually showed in a PNAS paper that a person's preferences for certain musical combinations is correlated with their preferences for certain color combinations, which seemed completely crazy to me. It just seems so far fetched. But there's this underlying aesthetic module that we can't account for yet.

Speaker 1

What was the argument there, did you guys forward a hypothesis? I read no?

Speaker 2

Oh well, I mean there was some hand waving. Yes, there's an aesthetics module, and yeah, I mean to some extent, it had to do with consonants and dissonance. Do you like to see contrasting colors and contrasting chords? Do you like to see things that are more consonant and harmonious? But sharp edges and the metaphorical sharp edges and music. But apart from that, it was pretty speculative.

Speaker 1

So let me double click on this issue about individual differences, because one thing that's clear is across the population, some people don't really like music that much. Other people love music, it's a big part of their lives. But on one on the spectrum, you just it's sort of meaningless to many people. So how do you interpret that?

Speaker 2

Well, I just look at this as as a necessity of Darwinian theory, which is that we can't all be alike, or we'd you know, genetically or behaviorally or we would all be wiped out by a single opportunistic virus. So, you know, a cornerstone of Darwinian theory, as you teach it, as I teach it, is descent with modification and random mutation. And so you know, most random mutations end up being unobservable. Some of them we see a phenotypic variation, that is

a behavioral variation. And in that case, yeah, ten percent of the population probably don't like music, and they don't understand why the rest of us spend so much money and time on it. Ten percent of the population probably don't like chocolate. I find that so impossible to believe, but they don't. And then there are you know, some percentage of the population don't like sex. They tend not to pass that on through reproduction, but that trait, but it's the way it works.

Speaker 1

How do you think music fits into the story of evolution and human evolution in particular.

Speaker 2

So Stephen Pinker famously threw down a gauntlet in nineteen ninety seven when he said that he thinks that music has nothing to do with evolution, that it was just sort of a byproduct of other things that we developed, like language. He called music auditory cheesecake, And what he was saying was that, well, we didn't really evolve to like cheesecake. We evolved to like sweets and fats because in the very small amounts they were available across evolutionary

time periods to it was adaptive to seek them out. Now, if you get cheesecake, it'll just you know, you know, spike your blood sugar levels and be bad for your health.

Speaker 1

I'm curious if you have a different view on it, whether there's a role in evolution for music.

Speaker 2

We do have some data and I'd like to share that with you, our and our listeners. So to begin with, I mean, just as a resource, I would mention Stephen Mithen's book The Singing Neanderthals, where he makes the case that music was a proto language that preceded, you know,

linguistic language speech. I would say the evidence that we have from neuroanatomy is that, from the work that Vanode Menon and I have done in others, those circuits that are engaged with music, listening and performing are phylogenetically older than the speech circuits. And that's the reason why Gabby Giffords was able to recover speech after she was shot in the head and lost the ability to speak. It's

called melodic intonation therapy. We can take somebody who's lost speech ephasic expressive aphasia and teach them to sing what they need to communicate.

Speaker 1

So give us an example of that. What Gabby Gifference does.

Speaker 3

Well.

Speaker 2

She could not speak, but she might have been taught things like I need a glass of water, show me to the bathroom, I'm ready for bed now. She could sing those things perfectly, and through neuroplasticity, the brain rewired itself by passing those damaged circuits using the intact music circuits. They are phylogenetically, that is, evolutionarily older. That's one piece

of evidence. Another is if we look at contemporary hunter gatherer preliterate societies or all around the world that have been cut off from Western civilization, and we make the assumption, David, that they're living life now pretty much as they have for ten or twenty thousand years, and all of them use music for a number of things, not just a single thing, but the emerging ideas that music evolved as many things did, not for a single to solve a

single adaptive problem, but multiple problems, and one of them was how do you encode knowledge in a pre literate society. We've only had a written language for five thousand years. We've been on the planet ten or twenty times. As long as that, we still had to remember things like, oh, don't go over that hill there, because my grandfather went over there and they killed him because they're very vicious

and warring, and so you know, don't go there. And when this water well runs dry, this is a route to the other well, the supplementary one. Don't eat that plant unless you boil it in this particular way. This kind of knowledge is embedded in song in pre literate hunter gatherer tribes and probably has been for a long time. Mothers soothing their infants to imprint their infant on their voice so that if they become separated, the infant will

know the sound the mother's voice. So we've got knowledge, we've got bonding between mother and infant. We have social bonding. Singing around a campfire to ward off a neighboring tribe or predators as a way to defuse interpersonal tensions within a tribe and to protect you from outside invaders.

Speaker 3

Lots of different uses.

Speaker 1

Let me double click on this for a second. Do you feel that music is universal in terms of when you compare across culture around the world, or are there important differences locally both.

Speaker 2

Music is a cultural universal. There is no known culture now or any time in the past that lacked it. In David Huron's words, music is marked by its ubiquity and its antiquity, and there are huge local variations. One thing in common is we all have the octave, which is defined by frequencies that are double or having of one another hundred hertz, two hundred hertz, fifty hertz, all the same. We perceive them as perceptually very similar um

similar notes. We give them the same name. In Western system, there's middle C and there's high C, and there's low C, things like that.

Speaker 3

But the way we divide up the.

Speaker 2

Octave into pieces is different across cultures. We divide the octave up into twelve pieces, and we tend to use only five or seven of the notes at a time. The patterns that we make once we've divided the octave, the way we combine them, either sequentially or simultaneously melodies and chords are different. And that's why Chinese opera and the music of Sub Saharan Africa sounds so different to us.

It's based on different customs and a different system. And it's not the case that our music is better or that if only you went into the Amazon and played the indigenous people their mozart, they would feel that they had suddenly heard from God himself. It doesn't work that way. We've done the experiment.

Speaker 1

What is their impression of it?

Speaker 3

Eh? Meh? Yeah.

Speaker 1

Presumably whatever you've grown up with culturally affects your enjoyment of what you're hearing, right.

Speaker 3

Very much.

Speaker 2

So. Yeah, we imprint on the music we're raised on, and so we implicitly learn the grammar of our music the way we implicitly learn the grammar of our language. As Chomsky had said, here's a little test. Hang on a second. Okay for the listener, Dan has des grabbed his guitar, So we all know implicitly, uh scales, even if we don't realize we do. Now you're expecting another note. You're probably expecting this one.

Speaker 1

Thank God about that? Yeah, otherwise.

Speaker 3

That doesn't sound bad. But that sounds quite not quite right.

Speaker 2

And we know chords. We know that if I go it wants to go somewhere.

Speaker 3

I can't just stop I've got to come back to.

Speaker 2

Or or.

Speaker 3

There's some options, but not unlimited options, right.

Speaker 1

And I've talked in many episodes about how fundamentally the brain is a prediction machine. It's just it is trying to guess ahead at what's going on. It's got an internal model of what's coming next. So in those cases, let's say, with the chords that you were playing, is it the case that I had certain predictions because of the culture I've grown up in. To what extent would that be universal about what chorn comes next?

Speaker 2

Absolutely, and something I very much appreciate about you, because this is not something that all cognitive scientists cognitive scientists talk about, but you and I, I think, have been big proponents for this idea that if the brain is if the brain is nothing else, it is a giant prediction machine. That is its job. It's just based on

what we've heard over and over and over again. And the job of the composer and the performer is to reward those expectations just enough of the time that you feel like you're following along with the story as it unfolds. But they have to surprise you just enough of the time that you've learned something, or you get that little hit of oh, isn't that interesting? As much as I was trying to predict what comes next, they came up with something even better than I could have imagined.

Speaker 1

Just like with everything in life, there's a spectrum between novelty and familiarity and all the sweet spot is in between that. Somewhere on that note, what is the reason that we care for rhythm so much? Do you feel as I do that it has to do with predictability, where the brain says, oh, now I know what's coming next. There's the next beat, in the next beat, and there's something very satisfying about having some structure of prediction, and then there's surprises thrown on top of that.

Speaker 2

It's because the brain's a prediction machine that rhythm is meaningful to us. There are populations of neurons that fire in synchrony with the beat, with the tempo that sets us up for movement. And I mean that metaphor and literally, music is possibly the only art form that makes you want to wiggle your body in response to it. People aren't standing in front of the Mona Lisa and dancing.

Speaker 3

Although they do, they.

Speaker 2

Seem weird and they might get kicked out of the louver, but we dance to music because we can't help it. And in the neuroimaging studies I've done all of them, where we ask people to stay still, we still see activity in their premotor cortex and their motor cortex that they're trying to suppress. And then on the metaphorical movement, yes, rhythm is important because it's telling us that there is more to come and we want to know what that is. It sets up a narrative momentum and when a musician

could play around with that rhythm. If you listen to what Stevie Wonder does and the opening to Superstition, I can't replicate this exactly, but he's playing around on the high hat. He's setting up a beat. The high hat's that little symbol and ordinarily a normal drummer would just go, but Stevie doesn't goes. He's playing around. No, two times are the same, and we may not notice it because he keeps the underlying pulse there, but it is ear

Candy Man. It is just so interesting for the brain to take all that in, even at a subliminal level, that there's so much going on, and not only is he changing in the rhythm. He's moving his stick around so he gets the bell of the symbol, he gets the edge, he gets the middle, he gets different sounds out of it.

Speaker 1

So this is a good segue into something I've been wanting to ask you, which is, what is your take on artificial intelligence and music the future of And there are two ways to think about this, of course. One is AI composing music. Another is AI finding the perfect music for you. Maybe there are other ways to think about it as well, But tell us your take on the future.

Speaker 2

AI composing music. I look at it this way. I have a friend, a novelist, Gail Jones, wonderful novelist, who says that AI music now is like those artificial flowers at a holiday inn. You walk in the lobby, you see this big display and you go, wow, isn't that nice? And you get up close and you realize they have no nice odor and they're plastic, And so AI music at a distance probably sounds just fine. And it's already crept into advertising on social media. It's being used in

the background. It's sonic wallpaper. It's kind of like the painting in the bedroom of that same holiday in room it's like, Okay, it's covering the wall. It's kind of nice, but I'm not going to sit there and stare at

it for hours. I think that you and I subscribe to Dan Dennett's functionalism, the idea that in theory, all of our thoughts, hopes, desires, and beliefs, all of our mental activity can be redo to brain activity, and that brain activity can be characterized by patterns of neural firings and connections if you could replicate a human brain and add in the right amount of random factors. I think in theory, yes, AI music could be great. I don't like the thought of it, but I mean that's the reality.

But for now, I don't think AI music is going to be a threat to real music and real feeling. But you nailed it on the head. Where I think AI can be the most use is helping us to find music that we like. Most of us listen to a couple of thousand songs maximum, over and over and again, and occasionally let in a few new ones, and those can be comforting and rewarding, but they can dig deep neural ruts such that we get tired of them and

we want something new. There are now two hundred million songs across the streaming services, with a one hundred thousand new ones being uploaded every day. So how do you find what you like? The major streaming services have recommendation systems.

They don't work particularly well for me, But AI in principle can extract hundreds of features latent features for music and build a multi dimensional model, a higher dimensional manifold of musical structure and DNA that might have one hundred and fifty orthogonal dimensions, and set up a kind of universe of music where things that are where each song is like a planet, and planets that are near each other are going to be similar, not just structurally, but

in an emotional space where they're likely to cause a similar emotional reaction in a given listener, knowing what your own personal space is, right, It's not going to be something that is entirely objective and prescriptive and one one hundred and fifty dimensional map for everybody. They'll have to be to maps for each person, because your tastes are different than mine. As my grandfather used to say, if everybody liked the same things, they'd all want to get with your grandma, I'm going.

Speaker 1

To steal that line if you don't mind, when I'm a grandfather. What have I not asked you that I should ask you?

Speaker 2

I wanted to ask you of the many successful books and highly regarded books you've written, did you write them because you wanted to read them and you couldn't find them? Or did you write them because you just thought that you had a different take on something than others?

Speaker 1

Oh? No, I actually know precisely why I write my books and who I'm writing them for, which is I'm writing them for the younger version of me that didn't know those particular facts when he was younger, but would have loved that. That's who I'm always writing for.

Speaker 2

You know, Joni Mitchell taught me about something about songwriting that was really transformative and my songs I've been writing since I I was eighteen, but since Joni told me this in two thousand and five, I not only did my current songs get better, but I went back to the old ones and started rewriting them. And what she said was, you don't write a song because you figured something out. You write it in order to figure something out.

Speaker 1

That was my friend and colleague Dan Levitton, neuroscientist, cognitive psychologist, writer, musician, and record producer. So what has emerged from a couple of decades of the study of music in the brain is that music can't be understood simply as different pitches

hitting the ear. The sounds of music trigger a neural hurricane of spikes on the inside of the skull, and this correlates with the pitch in rhythm and timbre, but it jins up a silent neural symphony, and that activity is closely tied in with our emotions and it pulls strings to our memories. We don't just hear music, we

actually resonate with it neurally. So the brain doesn't just process music, it magnifies it, which shows us once again that the ultimate instrument is not the piano or the guitar, but the one between our ears. Go to eagleman dot com slash podcast for more information and to find for

Transcript source: Provided by creator in RSS feed: download file