From Perception to Pleasure: How Music Changes the Brain | Dr. Robert Zatorre | TEDxHECMontréal

so today's theme is about change and so I want to tell you about how music changes the brain and also a personal story about how it changed my brain and so I'm going to start with that and I want to tell you about when I was an adolescent and like many adolescents I was listening to the music that all of my friends were listening to which was sort of you know mediocre rock-and-roll music and one day somehow I came into the possession of a record album this is what a vinyl record looks like for those of you who aren't familiar with it and this is music by béla bartók the Hungarian composer who died in 1945 I had never heard of Bela Bartok I had no idea what it was I really just randomly sort of put it on just to see what it sounded like and this is what I heard [Music] so I still get chills when I hear this and back then when I was like 13 I experienced this epiphany I had I'd never heard anything like this I had chills down my spine I had goose bumps I just felt this unbelievable sensation that I I really couldn't explain and so I it really changed me in the sense that I it gave me a focus about something that I really needed to pursue and so I decided right then that I would try to understand more about music I would try to learn about music I would try to learn to play music and that I would also perhaps try to apply science to music because I was already quite interested in science I was already training as a scientist and so I tried to put these things together now the experience that I had of course is one that probably many of you have had and indeed it is something very common in our species so human beings have been enjoying music for extremely long time so this flute for example that you see here dates from the Upper Paleolithic period that's about 35 to 40 thousand years ago and this particular specimen was found in a cave in the Danube Valley and what is now part of Germany what's remarkable is that at that time this part of Europe was under glaciers so you know the living was not easy at that point for these people who were making these remarkable musical instruments so they must have felt a tremendous power of music to devote energy and resources and time to the creation of musical instruments it must have been extremely important in some sense for their survival that they would even carry out these activities when survival was so difficult otherwise so how is it what are the what are the brain systems that allow us to be able to create music to perform on musical instruments to perceive musical patterns and to experience the pleasure from them well we know a fair bit about this now over the last few years in many laboratories around the world and in mine as well we have been trying to dissect some of these neural pathways and this diagram tells you a little bit about some of the important circuits that are involved in connecting different parts of the brain particularly those that involve perception of sound and the motor system for production of sound and kind of a close-up look of it is here so the colored areas represent the portions of the brain that are devoted to the perception of sounds this is known as the auditory cortex and then you have connections going from there to other regions particularly those that involve control of the motor system so you have a kind of a loop between the auditory and the motor systems that allows us both to perceive and to produce music and a point that I want to make is that when you become trained in music you basically fine-tune these circuits to a remarkable degree in this video that I'm going to show you in a second which is courtesy of my colleague marcelo wonderly what you will see is the motion trajectory of the bow of a violin as the violinist is playing so there's a sensor at the tip of the bow and as the violinist is playing you'll see the patterns that it creates and I want you to pay attention to the precision with which these patterns are shown so that you'll see that the movements completely overlap one another in quite a beautiful way [Music] see those loops you see how they're perfectly superimposed on one another [Music] look at this figure eight as we're playing on two Springs your form is figure eight [Music] sometimes I think we should just forget about the lecture and listen to the rest of the Partida and we would be very happy so what allows this level of precision how is it that you can train your brain to be this accurate well one thing that is interesting is that musical training can actually change your brain structure and this was actually predicted by Santiago Ramon y Cajal who won the Nobel Prize for medicine and physiology 1906 and in 1904 he actually predicted this idea that the brain might be physically changed by training so he specifically mentioned the idea of musical training he said the ability of a Penant of a pianist requires many years of mental and physical practice and to understand this phenomenon fully we have to admit the formation of new pathways and progressive growth of nerve terminals so he had this idea that the anatomy of the brain could actually be changed by training and this concept was just a hypothesis at the time he didn't have any direct evidence for it but in our laboratory and others we've been able to demonstrate that indeed there are some of these anatomical changes so what you see here are the two halves of the brain the two hemispheres left and right and the colored areas represent areas where the thickness of the cortex is actually greater in people who've received musical training compared to a control group who does not have musical training and the areas that distinguish these groups are not surprisingly the auditory areas that I am showed you earlier as well as the motor cortex and importantly areas of the frontal cortex which are involved in many types of higher order cognitive functions including executive functions like planning or anticipation or being able to create to pay attention to new new events that are coming up one important detail about this sort of result is that it is linked to the age at which you start training so we see in this image the blue region is a an area of the frontal cortex but it's degree of change is linked to the age at which the person began to train with music so the earlier you start the more change you have and this is quite important because it speaks to the plasticity of the brain which is greater in earlier ages than in later ages and you may recall I said I was about 13 when I had that experience of music and so I'm one of those blue dots over there so my my frontal cortex isn't quite as developed which is really why I'm here giving you a lecture about science and not you know playing an instrument which is perhaps what I would do had I started early enough now all of this that I've been telling you about is with respect to the ability to perceive and to produce music but really what I would like to tell you about is about how it is that we experience pleasure from music and to do that we have to go to a very different system of the brain so everything I've been talking about up until now is in the cortex which is the outer part of the brain now we have to go into the deep structures and there's one particular structural structure known as the striatum which is especially important in the representation of pleasurable experiences and this has been discovered many many years ago so that for example if you take a lab rat and you give it food and you measure activity in its brain you will see that in this area known as a stratum the dopamine neurons will be more active when the animals receiving food so this is basically a kind of a chemical signal within the nervous system saying well this is really good this what you're getting now is really important you should try to get more of it if you can and it's not just in lab rats what we can see this in healthy human participants as well so if you put people in a brain scan machine and you give them monetary rewards so you play some kind of a gambling game for instance or you give them food rewards or you expose them to erotic images you will see a very similar response in this deep structure known as the striatum that's what this slide illustrates so there's a common activity in this what we call the reward system to the stimuli which are essentially essential for survival so you need food opposites survive you need sex for the species to survive for reproduction and monetary rewards you need them only insofar as the money is fungible right so you can exchange it for some something of value and so we wondered could it be that music would engage the same biological system even though it is not a substance you also get these responses to drugs by the way but music is not a chemical substance it's not strictly speaking necessary for survival and indeed we've been able to demonstrate that in a series of experiments you very consistently show that the stratum is active - highly pleasurable music we've seen this with blood flow when we measure blood flow in the brain we see it with dopamine receptors so when we measure dopamine uptake while people are experiencing pleasurable music we see an increase in the stratum and we can also see it with functional magnetic resonance imaging which measures blood oxygen and there again we see in and this last study is sort of interesting because what we were doing there was looking at how much value people assigned to music so in this experiment people were exposed to pieces of music that they hadn't heard before and they were asked to decide whether they wanted to buy it or not and if they did they had to put a certain amount of money down so it's kind of like iTunes where you hear a little extra bit of music and then you decide you want to buy it and you can pay different amounts so the way the experiment proceeds is like this you might hear the first sample well that's okay maybe we'll give it $0.99 all right now the next sample comes in now I don't really care for that I think I'll give it a zero go to the next one this is kind of groovy maybe I'll give it a dollar twenty nine so in the experiment what we do is we use the amount of money as an estimate of the value for that individual to that particular piece of music and then we look in the brain what's happening with our functional imaging device and what we see is not only that the reward system is active in other words there is more of a response in this region we call the stratum the more money you're willing to give but also and very importantly the reward system increases it's communication with the auditory cortex the more value that is assigned in other words those regions that I talked about earlier in that have to do with perception are more strongly coupled with the regions that have to do with emotion and reward the more you like something the more you'd like the music and so this basically links these two systems of the brain on the left side we have these cortical systems which are actually the most phylogenetically advanced parts of our brain these are the parts of our brain that distinguish us from other species including other primates to a greater degree than any other region and all of these cortical areas have to do with perceiving sounds and being able to plan for the future which means that you as you hear music unfolding you're able not only to perceive the sounds but you also have an expectation about what the next sound is and the musician or the composer will sort of play with those expectations so that they are fulfilled to a greater or lesser extent that's all so we're very cognitive but on the other hand we have this interaction with what is one of the most phylogenetically parts of our brain which is the these deep structures in the reward system which we share with many other animals so music represents a kind of a fusion if you will of these two systems the most sort of advanced cognitive system with the most powerful emotion and reward systems and this is basically the idea that I want to leave you with is that music has a great power to engage us to make us feel emotion and to change our brains and the way we're thinking of it is that it derives this power precisely because it combines these two very very important systems in our brain and that I think is the message that I want to leave you with and also I think the idea that by combining science and art we can actually gain a deeper understanding in the two domains that these are not two separate domains that really should be fused and I think if we want to think about change we want to think about how can we bring science and art together thank you very much but is that okay you

Channel: TEDx Talks

Views: 141,685

Keywords: TEDxTalks, English, Social Science, Brain, Music (topic), Science

Id: KVX8j5s53Os

Length: 15min 50sec (950 seconds)

Published: Thu Apr 12 2018