Kim Mills: Do you get chills when you hear the chorale from Beethoven’s Ninth Symphony? Does Samuel Barber’s Adagio for Strings make you tear up? Are there songs that transport you to another time, whether it’s music by The Beatles or The Police or Nirvana? Does some music make you happy and want to dance? For many of us, music taps into our deepest emotions and memories, and yet for others, music is just meh. Over the last several decades, psychologists and other researchers have begun to explore why music affects us so profoundly. What happens in the brain when we listen to music or when we sing or play an instrument? Why does some music give us goosebumps while other pieces leave us cold? On the other hand, why do a small number of people experience almost no emotional response to music at all? And what can studying music and the brain teach us about broader questions of perception, memory, language, and cognition?
Welcome to Speaking of Psychology, the flagship podcast of the American Psychological Association that examines the links between psychological science and everyday life. I’m Kim Mills. My guest today is Dr. Robert Zatorre, a professor in the department of neurology and neurosurgery at McGill University, who holds a Canada research chair in auditory and cognitive neuroscience at the Montreal Neurological Institute. For decades, he’s been a pioneer in the neuroscience of music, studying how the brain processes music, speech, and sound, and why music can evoke such powerful emotional experiences. His research has helped to explain how the brain’s auditory and reward systems work together to create musical pleasure. He’s examined topics ranging from musical anhedonia—the inability to derive pleasure from music—to the relationship between music and language. He’s author of more than 350 scientific research papers as well as the book From Perception to Pleasure: The Neuroscience of Music and Why We Love It.
Dr. Zatorre, thank you for joining me today.
Robert Zatorre, PhD: Thank you very much for having me, Kim.
Mills: Let’s start with a big picture question. I read in a previous interview that you said music touches every cognitive function there is. Can you talk about that? How does music touch so many different aspects of human cognition?
Zatorre: Part of the reason I say that is when people ask me, Well, what’s the value of studying music scientifically? I often like to point out that music is not merely a pattern of sounds. It is that of course, but that’s just a start. And so we can use music to understand the auditory system. Absolutely, that’s a key feature. But at the same time, music engages many, many other functions. So if you consider, for example, an everyday situation, you’re waiting for an elevator and somebody walks by and they’re whistling a tune. And you recognize the tune, even though you have never heard it being whistled before, you know what it is. You immediately think of the fact that it was being played last summer when you were at the beach with your best friend that you hadn’t seen for a while. This brings back memories.
At the same time, you start to tap your foot as you imagine the music. So even though the music is gone, the person walked by, you can still actually hear it in your mind’s ear. As you do so, you might tap your foot, you might sway to the rhythm of the music, engaging your motor system, and it may also just be a very pleasurable experience. You may actually find that you’re in a better mood just because you were thinking of that music. So just think of all the list of cognitive operations that went through there. There’s some kind of auditory processing, there’s some engagement with a motor system, there’s an engagement with a memory system, there’s an affective response, a hedonic response, an emotional response, et cetera. So this is why I like to say it engages the whole brain—in the sense that it is a very complex type of human activity that doesn’t stop just at the level of sound, but it is really, I think, remarkably interesting from that perspective because it is so rich.
Mills: Now you found in your research that there’s a link between music and pleasure that can be traced to the brain’s reward system. How does that work? What’s happening in the brain when we’re enjoying listening to music?
Zatorre: Yeah, so this is a very, very important part of our research. For years, psychologists and physiologists had studied the so-called reward system. This is a series of structures in the brain that are known to be very important for reward. So what does reward mean in the classical psychology sense? It means a reinforcer. It means a stimulus that causes the behavior to be repeated, but there’s also a hedonic part to it. So although the behaviorists didn’t like to talk about that, cognitive psychologists do like to talk about emotions. And when there is a rewarding stimulus, it is typically pleasurable. You feel a sense of pleasure. It’s positive in some way. And all of these sorts of effects have been traced to dopaminergic neurons in certain structures, in the striatum in particular, which is a deep nucleus in the brain, as well as other parts of the brain, the orbitofrontal cortex and the amygdala and ventral tegmental area. There’s a whole complex circuitry.
Now, about 25 years ago, we discovered that music actually activates the same reward system as had been identified for other types of rewarding stimuli. So essentially there’s a single reward system that responds both to primary rewards, things like food, for example. If you take a hungry animal and you measure its response to food by putting an electrode into its brain, you’ll see that those dopamine neurons are very active when the food is delivered. Nobody really knew, including us when we discovered it, that a completely abstract stimulus like music could also engage that system. But indeed that is what we found using brain imaging techniques.
And then a few years later, we were able to demonstrate that the response is actually driven by dopamine neurons. We know this because we can use technology to measure dopamine response in the brain non-invasively. We have positron emission tomography, which is a way of measuring the chemical activity in the brain. And more recently with some colleagues in Spain, we did some experiments where we manipulated the dopamine levels pharmacologically by giving volunteers certain drugs that would either elevate or inhibit the dopamine system. And we found that indeed music given after the administration of the dopamine precursor actually gave more pleasure. And when you gave the dopamine inhibitor, it actually resulted in less pleasure. So this links music to all of these more biologically given sorts of stimuli.
And I think raises very interesting questions about how is it that our brains are able to respond to this completely abstract stimulus that we call music? And it’s not just music by the way, it’s other art forms as well. And how is it that this very kind of primal survival related mechanism is brought into play? And I think that’s a topic that we’re very actively pursuing. We and many other laboratories around the world.
Mills: So what you described just was about appreciation of music, reaction to hearing music, but what about producing music? Is there a structure in the brain that’s responsible for musical comprehension?
Zatorre: Well, there’s actually a very, very tight coupling between the auditory system and the motor system. So we can see that if we measure, for example, brain oscillations in the motor part of the brain, the part that controls the muscles, and the auditory part of the brain, the part that is responsible for processing sound, we see that the oscillations are very strongly coupled. They’re in phase with each other between the auditory and the motor system in a way that doesn’t quite happen, for example, if you look at the visual and the motor system. So they’re not as strongly coupled as they are for the auditory and motor. And we think that this means that there’s a very close relationship between perceiving sounds and generating sounds.
If you think about it for a moment, basically every sound that you hear is the outcome of some action. There can’t be sound if no action has occurred—with some very, very slight exceptions like, I don’t know, thunder. And even then there’s some action in the cloud, there’s some kind of interaction between the molecules. So if you have a completely static environment where nothing is changing, it’ll be a silent environment. So already at level of physics, there’s a close link there. And if you think about it from terms of biology, many, many actions, not all, but many actions produce sound, including when we speak. Right now I’m moving my lips and my tongue and my larynx in a coordinated manner to produce certain types of sounds. Same thing when I walk. When I walk, you hear footsteps. If I clap, you hear sounds. So all those sounds are the outcome of different kinds of actions.
And I think if we think about it from sort of a biological perspective, this is something that’s very, very fundamental. From the first moments of life, we hear sounds that we produce ourselves. What’s the first thing that an infant does upon emerging from the womb?
Mills: It cries.
Zatorre: Yeah, if it’s healthy, that’s what it will do. So literally from the first moment, you’re activating your vocal tract and producing sound. And so this I think is kind of a very, very basic level, is the link between movement, action and sound. And also these things influence each other. So if I’m playing a musical instrument or if I’m speaking, the action that I make will produce a certain sound. But if I’m playing an instrument, for example, I have a certain target in mind. The sound is supposed to be a certain note with a certain tone. So as I’m playing, let’s say I’m playing a violin, as I’m drawing the bow across the strings, I’m listening to the sound. If it’s not what I wanted, my auditory system will feed back to the motor system and say, no, you have to adjust your vibrato or you have to press harder with the bow or what have you.
So it’s a constant interplay. The sound influences the action. The action generates the sound. So it’s a feedback loop between the two things. And that’s true for music, it’s true for speech, it’s true for other activities that might also generate sounds.
Mills: Well, getting back to the question of pleasure and music, there’s some people, albeit not a lot, who don’t get any pleasure from listening to music—musical anhedonia it’s called. This is something that you’ve studied. What causes it? And can it be overcome by somebody who doesn’t get anything from music but would like to enjoy it?
Zatorre: Yeah, this is a very interesting phenomenon. We discovered it about 15 years ago or so, because prior to that, I mean everyone including us, we had the assumption, well, of course everyone loves music. And then we started thinking about it more seriously. And a scientist, you’re supposed to question your own assumptions. That’s supposed to be a part of science. And I have very good students and they will often question my assumptions. That’s part of their job. And I like to encourage them to do that. And so one of them sort of said to me, Well, how do we know that everyone likes music? And I was like, Oh, well, I don’t know. I’m just taking it for granted. Well, why don’t we actually find out?
So to make a long story short, we developed a series of questionnaires. We went out into the field. We tested a few thousand people to figure it out. And what we found really to my surprise is that about something like 2% of people or so who are otherwise completely healthy, there’s really nothing wrong with them—I don’t refer to this as a disorder exactly because they don’t think there’s anything wrong with them. And I think it’s part of neurodiversity actually. I don’t think it should be looked on as a negative sort of thing. But these are people who report no pleasure to music, even though importantly, they experience pleasure to everything else.
And I mentioned the reward system earlier as responding to food or other pleasurable activities, including, for example, social interactions, including intellectual sort of experiences, including of course, romantic love, sex. These are things that activate the reward system. So these people with musical anhedonia, they respond to all those things. We tested them very specifically by having them play really kind of addictive video games where you can win some money. And we know this activates a reward system. This is why those games are annoyingly addictive. And when we gave those games to these people, they got hooked on it just like everyone else. But when we played music to them and we put them in a brain scanner, we noticed there was no response at all in their reward system—or very, very limited. And so this is exactly in line with what they report on questionnaires. When you ask them, they say, Well, of course I like to go watch a movie with my friends, and then I like to go out for a meal afterwards and maybe enjoy a few beers. And I have a boyfriend and I like to hang out with him and et cetera. These are all the normal pleasures of life. But when I’m with my friends and they say, Oh, let’s go to a concert, I’m always completely blank about it.
And then they tell me, Oh, you have to listen to this new band that just came out. And they put the music on and I’m completely flat. And I tell them, No, music just doesn’t do it for me. And so this is very interesting because it means that the way that we experience music can be dissociated from the pleasure response that we talked about earlier. And when we dig further into the brains of these folks with musical anhedonia, what we observe is that literally the connection, the white matter fibers that connect the auditory part of the brain with the reward system, that system is less robust than it normally is. That pathway is not as well-structured as it typically is. And so we think this is very likely a congenital sort of effect. People usually tell us that this is something that they’ve had ever since they can remember. It is not a recent something that happened.
And so like I mentioned, I think it’s good to think of it in terms of neurodiversity. People’s brains are wired in different ways. And even though most of us are really wired for music—some of us very strongly so, we call them hyperhedonics—there are some people for whom music is really not emotionally engaging. And by the way, there’s nothing wrong with their auditory system either. We of course check for that. We test for their ability to distinguish the pitch of different tones and things like that. So it’s not that they can’t hear the patterns, it’s just that the patterns are not especially emotionally engaging for them.
Mills: And given the brain’s plasticity, as we now understand it, is there a way to train yourself to appreciate music if you are anhedonic?
Zatorre: Yeah, that’s a really good question. One of my colleagues is in fact testing that right now. I’m skeptical that it will work because if this connection that I talked about is physically not as functional as normal, then I think the absence of that pathway suggests that, to me at least, that it probably isn’t something that’s easy to train. But I have to keep an open mind about it because we do know that these pathways often can be enhanced with different kinds of experience. So it is possible. I don’t know. We’ll see. We’ll know maybe in another year or two when my colleague’s study is finished.
I mean, many of the people we talk to with musical anhedonia don’t report it as any kind of hindrance to their lives. They say, No, my life is perfectly fine. I don’t get music. That doesn’t bother me. So I think we just have to be careful about respecting how people feel about it. It’s not a disorder that needs to be cured necessarily.
Mills: Right. Well, for a lot of people, music has an amazing ability to bring back memories. A particular song might transport us back to the moment when we first heard it or to a significant event in our life. You were talking earlier about even just hearing a little bit of a snippet of somebody whistling a song could bring back a memory. Why is music such a powerful cue for autobiographical memory?
Zatorre: Yeah, this is a topic of great interest and there’s a lot of very good research going on right now attempting to answer that question in some detail, especially because if we can figure out why it is, why it is the case, we might be able to develop certain applications like therapeutic applications for people with memory disorders. So that’s something that I think is important to research. The short answer that I would give goes back to the reward system because we know that the reward system is central to memory formation. I mentioned at the very beginning that reward is related to reinforcement. So reinforcement learning goes way back in psychology to the middle of the previous century. And the idea is that you learn to perform certain actions based on how rewarding they are, which means that you’re encoding information and you’re encoding that information better when your dopamine levels are higher and less well when your dopamine levels are lower.
And this makes perfect sense from a biological perspective. You want to remember the things that are important, the things that are salient, the things that will bring you reward compared to things that are kind of trivial or unimportant. So it stands to reason that since music does activate the reward system, when you are listening to that music, you are in a state of heightened information processing, which leads to better memory formation. And so that I think is part of the reason why we have these sometimes quite strong autobiographical sorts of effects because typically they’re very emotionally salient events as well. So it’s the emotion generated by the music, but also the emotion generated by the event. The two together cause an association to be formed between the music and the event, whatever it is that you’re remembering.
Mills: I want to talk about what makes music beautiful. Now, if you Google “world’s most beautiful music,” Google the source of everything, you get an amazing range of answers. I mean, everything from Barber’s Adagio that I mentioned in the intro to The Temptations’ My Girl, to the soundtrack for Phantom of the Opera, for example. But aside from the reaction of people who have anhedonia, are there any pieces of music that are universally considered beautiful?
Zatorre: I would say that the answer is no with respect to specific pieces of music. I would say the answer is yes with respect to specific principles that underlie different types of music. So let me unpack that for you a little bit. So music is extremely culturally dependent. So when someone says that they like The Beatles, presumably this is someone who grew up in a certain time period, in a certain place with a certain sort of cultural background. If you take someone who is a member of an isolated tribe in the Amazon forest, they have their own music and it’s probably not The Beatles. And if you play The Beatles for them, they’ll go, Nah, I don’t know what that’s about, but I prefer my flute and my drum, which are meaningful to me.
And this is true. Music is present in all cultures, but differs significantly, at least in its superficial expression in terms of the instruments that are used, in terms of the different scales that are used. We are all familiar with the Western scale. People tend to think that’s the only one that exists, but it’s absolutely not the case. If you listen to Indian classical music, they have ragas, which are quite different from the Western ones. If you go to Indonesia, they play gamelans, which have a completely different sound structure to them, and so on and so forth for many different cultures. The same for rhythms. In Western music, we tend to use duple or triple meters, but there are certain cultures in Africa, for example, that use far more complex metrical structures, meters of seven or 11, so prime number metrical structure, which sounds weird to us and we can’t even reproduce it, but they can.
So what makes music beautiful? I think there is a universal feature of what makes music beautiful irrespective of the culture. And that is the degree to which a particular moment of music is predictable or not. And there’s a fundamental principle in psychology which has been known from the time of Wilhelm Wundt in the 19th century, which is that you need to have a certain degree of surprise to experience something as pleasurable or important or salient, but not too much surprise and not too little surprise. So there’s a curve. It’s called a Wundt curve. He published it in 1887, I think. And it’s been demonstrated many, many times since. So what does it mean? It means that the brain is constantly trying to interpret what it receives from the environment and trying to anticipate what the next thing will be that’s coming. This again, goes back to a very fundamental survival mechanism. If you’re in an environment and you see a sequence of events, you want to be able to know what’s going to happen next so that you can be prepared to take the right action.
The right action might be to pounce and grab the prey and eat it, or the right action might be to run away as fast as you can, or the right action might be approach another member of your species with some proposal for lovemaking or something like that. These are all very different actions, but you’re always trying to anticipate what’s happening. Now, music is kind of a microcosm of that because music consists of a sequence of elements over time that are unfolding over time. And they follow a certain pattern depending on your culture. It might be a rhythmic pattern of a certain type, might be a scale structure of a certain type. Those differ across cultures. But across all of them, you always have some degree of expectation about what will happen. And the musician knows this implicitly. Every musician I ever talked to, whenever I explain this whole theory, they go, Well, yeah, of course we know this. This is what we do. We give you something a little different than what you were expecting. We don’t just give you the identical thing because that’s boring. If I play something like a major scale, if I play a major scale—super boring. No one would listen to that. Why? Because it’s too predictable. You know exactly what’s going to happen at every moment. If I play you a bunch of completely random notes, complete chaos, that’s also totally boring. Why? Because it’s all so unpredictable. There’s no structure. So you cannot predict what’s going to happen. But there’s a sweet spot that Wilhelm Wundt identified, which is the balance between predictability and surprise. So you want some surprise, but you also need some predictability. In fact, in order to get surprised, you need to have predictability. In order to be surprised, you have to be expecting that something’s going to happen. If you’re completely lost without knowing what’s going on, you can’t be surprised because you have no expectation about what’s going to happen.
So I think this is the key to what makes music and other art forms as well—people have applied this theory to poetry, for example, or to humor. The punchline is an unexpected event. Even to visual art, people have tried this. And I think that the reward system, coming back to that idea, is we know this from experiments. We know that it’s extremely sensitive to obtaining rewards that are unexpected. So I mentioned the classical experiments where you’re measuring dopamine from, let’s say, a rodent as it receives food. And sure, there’s a response. But what’s even more interesting is that you can condition that response on an unrelated stimulus. Let’s say a light goes on that signals that food will come. And the reward system will, once the animal is trained, will respond to that signal earlier in time. And then if the reward that it receives is larger than usual, you’ll get a huge boost in the dopamine response.
So this is what a reward system’s sensitive to. It’s sensitive to the reward you’re experiencing in relation to the cues that preceded it, the cues that predicted it. So if you’re following the music and you make a certain prediction, and then the musician plays a different chord that let’s say modulates into a different key, or there’s the entrance of a new voice, for instance, you’re hearing the bass guitar and then the singer comes in at a certain moment, maybe a slightly unexpected moment. These are the kinds of moments of music that people find super pleasurable. And it can be related back to these very fundamental mechanisms where you are surprised. You were expecting something, but what you got was even better than what you were expecting. And that’s where dopamine really kicks in and gives you pleasure.
Mills: I’m wondering if there is a connection between musical ability and language aptitude since music is an effective type of language. And it’s also a type of mathematics. I mean, you can’t really play music without having some fundamental intrinsic understanding of math. Do you see these connections neurologically?
Zatorre: Yes and no. I think we do see some relationships between these different functions, but not in the way that people usually think about it. So a common idea that’s out there that people are promoting because they can make money from it is that, Oh, well, if you give your kid music lessons, they’ll do better in math class. I’m not terribly convinced by the evidence for that. And besides, if your goal is to make the kid be better at math, they should take math lessons, not music lessons. I think music lessons are fantastic because music is fantastic, not because it’s good for math. So to me, that’s not quite the right thing.
Having said that, we do know that there are certain cognitive operations in the brain that are relevant for both music making and for something like math. And I’ll give you an example. So there’s a part of the brain, the parietal lobe, which we know is important for doing what mathematicians would call coordinate transforms. So that could be as simple as recognizing an object when it’s in one orientation and then you rotate it to another orientation and you recognize that it’s the same object. So this part of the brain in the parietal lobe is responsible for things like that, that we do very automatically and take for granted. You can extend that to actual math. So doing geometry for instance, or geometric theorems, or I don’t know, matrix algebra, there are many aspects of math that would involve similar kinds of computations. It turns out that there are also musical computations. These are implicit computations, right? You’re not aware of it. When you recognize the object in different orientations, you’re not thinking to yourself, Oh, there’s a rotation of 37.6 degrees, which corresponds to this transform. No, you just recognize it. Your brain is doing the math. You don’t have conscious access to those operations.
And some years ago we started thinking, Well, what’s the musical equivalent of moving an object in space? And we though, Oh, what’s an object? Well, let’s say a melody. How do you move it? Well, it doesn’t move in space, but it can move in pitch. And musicians call that transposition. This is a very commonplace function that you can recognize the same tune if it’s sung in different registers, for instance. That doesn’t take any special musical training ability. A child can do that without any special training. But if you think about what’s going on, think about the pitches of each of the tones. If I take, let’s say, a major chord, C-E-G, if I now transpose it to, I don’t know, let’s say the key of F sharp, now it’s going to be F sharp, A sharp, C sharp. All the tones are completely different, but you still recognize that the integrals are the same exactly. The relationships between each pair of tones is the same. Technically, it’s the frequency ratios between them. So when we do experiments where we ask people to recognize this is a major chord or not in different keys, what we see is that the same region of the parietal lobe is actually active as has been identified for things like visual rotation. And so that’s an example of a link between mathematical operations that apply in music and that apply in other domains. And so that I think is kind of a deep similarity between the two.
Mills: Another area of music that has interested me for a long time is musical autodidacts. The people who become highly proficient at music, but they never really had any formal training. And there are a lot of people on that list. I mean, in popular music, we’ve got Jimi Hendrix, Eric Clapton, and classical musicians like Edward Elgar, Telemann. What is happening in the brains of autodidacts that’s different from the rest of us who have to take lessons and practice and practice and practice and never really get great?
Zatorre: Yeah, it’s a great question. I don’t think we know the answer fully, but I think it’s a very interesting question because it gets at the issue of individual differences in musical ability. We do see that if you take a random group of a hundred people, you’re going to have all kinds of variability in their musical capacities. So 2% of them might have musical anhedonia. Another three or 4% might have what we call amusia, which is sort of tone deafness. But then another 5% will just be very, very good at something simple, like singing back a tune. So we all know that little kids can sing back tunes actually surprisingly well from an early age, but we all know that there are some kids who will not just sing it back, but sing it back with beautiful ability to shape the tones and to be very, very on pitch and so on.
So there’s this wide range of abilities out there. Most of us are somewhere in the middle. And I think it’s very interesting to try to figure out what is going on in the brains of those people who have some kind of innate ability that maybe doesn’t require formal training. It probably does require at least some significant exposure. In other words, even if you took Jimi Hendrix, when he was born, you put him in a place where no music was ever played, he probably would not have developed his ability. He must have heard a lot of music in his environment and had the innate capacity to figure out how to play it on an instrument and then how to generate even more new things that no one else had ever tried. So what exactly mediates that in the brain? I think it’s very much still an open question.
I would think that it goes back to the connectivity between different parts of the brain. Earlier we talked about the link between the auditory and the motor systems. I think it’s likely that there’s variability in that link across a population. Some will have a stronger link, most will have a medium link, some will have a very low link. The ones that have that stronger link, it seems logical to me that they might be the ones who, given the right opportunity, would be better able than everyone else to learn how to play an instrument because their auditory system is already highly communicating with the motor system. So they’re able to figure out, Oh, this sound pattern corresponds to this set of actions on a keyboard. And this set of actions I know is going to produce that set of sounds because they have the strong link between them.
So that’s one example. There are probably many other examples because again, music is so multifaceted. Some people who are very good at playing an instrument are not necessarily good at other things. Not every instrumentalist is a gifted composer or songwriter. There are other songwriters who famously were terrible at playing anything but could write beautiful songs.
Mills: I understand Irving Berlin could only play in the key of C.
Zatorre: I think that’s right. Yeah. I’ve heard that story as well, yeah.
Mills: There’s a growing interest in using music in healthcare and rehabilitation for people with dementia, Parkinson’s disease, stroke, other kinds of conditions. How do these therapies work? And do you think that basic research on music and cognition will contribute to more of these kinds of applications?
Zatorre: Yes, I feel very strongly about this and I have experience because I’ve been in this field pretty much from the beginning, going on 40, 45 years now. And I can tell you there’s been a dramatic shift in the way that people who work in music therapy respond to the science. So what I’ve noticed, because I actually am invited to speak to practitioners, clinical practitioners, people who do music therapy, people who do other interventions. They’re not necessarily music therapists, but they’re using music in some rehabilitative context. And what I find is that those people are finding that the basic science is extremely important because it gives them the foundation upon which to be able to build their applications. So compared to 40 years ago, people were doing music therapy, but it was very kind of impressionistic. They didn’t have any—it’s not their fault, they were doing the best they could, but they didn’t have very much to go on scientifically.
But now we do. And the techniques are becoming much more refined. I’ll give you a concrete example. There’s an NIH-sponsored group called Music for Pain that I’m part of. I think I’m the only Canadian who’s somehow part of it. And the goal of this group, it’s a large group of people led mostly by people who do music therapy. And they’re very, very interested in developing better techniques for analgesia and pain control via music. And there’s already experimental evidence that this can work, but exactly how it works, when it works, why it works, that’s still a matter of investigation. And so there’s tremendous enthusiasm in that community because they’re now starting to be able to say, okay, if you have chronic pain, you can use a certain kind of approach. Whereas if you have temporary pain from, somatic pain from an injury, then maybe a different kind of approach would work.
So it’s really applying the science very directly in clinical settings. And I think that’s something that is fairly novel. It’s only been in the past five, 10 years that’s been happening. And I think it’s a very, very positive development. It’s positive for the practitioners because they’re able to bring better techniques to their patients to alleviate their problems. And it’s also very good, I think it’s very rewarding for me personally, speaking of a reward system. It’s very rewarding that after working on this stuff for 40 years, somebody actually finds it useful.
And they come to me and they ask me, Well, what about the role of the reward system of this? What about the role of the motor and auditory cortex in that application? You mentioned Parkinson’s. A lot of the work in Parkinson’s to alleviate the motor problems is based on these models that have investigated the link between the auditory and motor systems. And the reward system is very much involved in the pain control idea. So yeah, I think it’s a very promising area. There’s still a lot of work to do. I would say it’s still relatively in its infancy, but I think the people working on it are on the right track. And I think in coming years we’ll see more and more and better applications.
Mills: Well, just to wrap up, what are you working on now and what big questions are you trying to answer at the moment?
Zatorre: Yeah, we’re working on a lot of different things. Some of the stuff we’re working on is very hardcore basic science. So we have talked a lot about the auditory cortex, for example. But if you’ve ever taken a physiology or anatomy course, you know that between the ear and the cortex, there are at least three or four subcortical structures that you have to get through that process sound. So from the ear, you go to the cochlear nucleus and then you go to the inferior colliculus, then you go to the middle geniculate. It’s what you learn in first-year anatomy class. But until very recently, our brain scanners could not even see those structures because they’re quite small. They’re very tiny. It doesn’t mean they’re not important. They’re just small, so they’re hard to see. So almost all of our theories are about the cortex, even though we know that by the time the sound information gets to the cortex, it’s been pre-processed three or four layers.
So now we have much higher resolution magnetic resonance imaging devices, which allow us to see these structures. The inferior colliculus is about the size of half of the nail on your little finger, 4 or 5 millimeters across. But now we can see it. We can actually visualize it. We can measure its activity. So that’s very exciting. From a hardcore basic science perspective, we’re starting to look at the wiring that underlies that processing. And then from a more applied perspective, we are becoming very interested in music and hearing loss. So hearing loss is a huge problem across society. It’s extremely prevalent. And it often impacts people’s ability to hear speech, of course, that’s what everyone focuses on, but it also impacts people’s ability to hear music. That’s much less studied. There are many, many fewer research projects on music as compared to speech. So we’re trying to fill that gap a little bit to try to figure out ways to improve music perception.
And one of the ways that we’re currently working on, I think is a fun project where we’re using the tactile sense. So we’re using the skin receptors on your hand, which are sensitive to vibration. If you ever put your hand on any vibrating object, you know that. If you put your hand on the radio when it’s playing, you feel a vibration, or an instrument. Indeed. In fact, musicians use vibration. If you play a fretless string instrument like a violin or a cello, the musicians feel the vibration on their fingers. And often on the violin, they feel it in their neck or in the cello, they feel it in their body and they use that information. So there’s a link between vibration and sound. And what we’re doing is giving people vibration through a special glove that we have. So the sound is fed to the ears and to the hand simultaneously.
And the idea is that if your hearing is not as good as it was when you were younger, you’ve lost some amount of hearing. Maybe, just maybe, we can substitute for some of that via the vibration through your hand. Of course, your hand is intact. Your hand does not have any loss. And so that’s one of the exciting things that we’re working on. It’s a bit more of an applied question than it is a basic science question. But the two things actually come together because in fact, what we’re realizing is that the subcortical structures that I mentioned that up until now we haven’t even been able to measure are probably involved somehow in the fusion of sounds and vibratory inputs. And so the more we know about the fundamental anatomy, physiology and functional properties of the brain, the better able we are to interpret and understand the findings even of relatively applied experiments.
So I think the two things really go together. You need the basic science. That’s the foundation of everything. And the better your understanding is of the basic science, the better able you will be to develop different sorts of applications.
Mills: Dr. Zatorre, I want to thank you for joining me today. It was really a pleasure to be able to talk to you and learn more about the work that you’re doing. Thank you.
Zatorre: Thank you so much, Kim.
Mills: You can find previous episodes of Speaking of Psychology on our website at speakingofpsychology.org or on Apple, Spotify, YouTube, or wherever you get your podcasts. And if you like what you've heard, please subscribe and leave a review. If you have comments or ideas for future episodes, you can email us at speakingofpsychology@apa.org Speaking of Psychology is produced by Lea Winerman.
Thank you for listening. For the American Psychological Association, I’m Kim Mills.
Robert Zatorre, PhD, is a professor in the department of neurology and neurosurgery at McGill University and holds a Canada research chair in auditory and cognitive neuroscience at the Montreal Neurological Institute. He is author of the book From Perception to Pleasure: The Neuroscience of Music and Why We Love It.
