Episode 49: Music & the Brain with Dr. Andrea Wilkinson

Introduction

In this episode, we’re trying a new format for the solo episodes, so let me know what you think!

Specifically, Dr. Andrea Wilkinson is going to select an interesting piece of content – either a book, an article, podcast or YouTube video to feature in the episode. She will read excerpts from the selected piece of content and then add in some of my own commentary and thoughts.

Let Dr. Andrea know what you think about this new format for the solo episodes (click here to send Dr. Andrea an email).

Featured Content: “This is your Brain on Music” by Dr. Daniel J. Levitin

Today’s episode will feature a New York Times Bestseller called “This is your Brain on Music: The Science of a Human Obsession.” This book originally came out in 2006 and was written by Dr. Daniel J. Levitin – an American-Canadian cognitive psychologist, neuroscientist, writer, musician and record producer.

Note, the parts of Dr. Levitin’s book that will be read were hand-selected by Dr. Andrea Wilkinson and span the whole book. Although Dr. Andrea will be reading excepts from his book as a continuous flowing piece of content (with some of my own thoughts sprinkled throughout) know that these parts of his book come from different sections of his book that she found interesting and pulled together for this episode.

Dr. Levitin’s book reads:

“This book drives at a neuropsychological perspective on how music affects our brains our minds our thoughts and our spirits. The basic elements of any sound are loudness, pitch, contour duration (or rhythm), tempo, timbre, spatial location, and reverberation. When we listen to music, we are actually perceiving multiple attributes or dimensions.”

“Pitch is so important that the brain represents it directly; unlike almost any other musical attribute, we could place electrodes in the brain and be able to determine what pitches were being played to a person just by looking at the brain activity…If I put electrodes in your visual cortex (the part of your brain at the back of the head, concerned with seeing), and I then show you a red tomato, there is no group of neurons [brain cells] that will cause my electrodes to turn red. But if I put electrodes on your auditory cortex and play a pure tone in your ears at 440 hertz (Hz), there are neurons [brain cells] in your auditory cortex that will fire at precisely that frequency, causing the electrode to emit electrical activity at 440 Hz - for pitch, what goes into the ear comes out of the brain!”

Your brain is an incredible organ and it perceives music in a unique way. But how our brain perceived music is different from how our mind interprets it. Have you ever wondered about how to distinguish your brain from your mind? Dr. Levitin explains this in his book:

“For cognitive scientists, the word mind refers to the part of each of us that embodies our thoughts, hopes, desires, memories, beliefs and experiences. The brain, on the other hand, is an organ of the body, a collection of cells and water, chemicals and blood vessels, that resides in the skull. Activity in the brain gives rise to the contents of the mind. Cognitive scientists sometimes make the analogy that the brain is like a computer's CPU, or hardware, while the mind is like the programs or software running on the CPU… Different programs can run on what is essentially the same hardware – different minds can arise from very similar brains.”

“Western culture has inherited a tradition of dualism from René Descartes, who wrote that the mind and the brain are two entirely separate things. Dualists assert that the mind preexisted, before you were born, and that the brain is not the seat of thoughts – rather, it is merely an instrument of the mind, helping to implement the mind’s will, move muscles, and maintain homeostasis in the body. To most of us, it certainly feels as though our minds are something unique and distinctive, separate from just a bunch of neurochemical processes.”

“Evidence for this comes from neuropsychological findings of regional specificity of function.  Sometimes, as a result of stroke (a blockage of blood vessels in the brain that leads to cell death), tumors, head injury, or other trauma, an area of the brain becomes damaged. In many of these cases, damage to a specific brain region leads to a loss of a particular mental or bodily function. When dozens or hundreds of cases show loss of a specific function associated with a particular brain region, we infer that this brain region is somehow involved in, or perhaps responsible for, that function.”

Music & the brain

“Musical activity involves nearly every region of the brain that we know about, and nearly every neural subsystem. Different aspects of the music are handled by different neural [brain] regions…. Listening to music starts with subcortical (below-the-cortex) structures … and then moves up to auditory cortices on both sides of the brain. Trying to follow along with music that you know - or at least music in a style you're familiar with, such as baroque or blues - recruits additional regions of the brain, including the hippocampus - our memory center - and subsections of the frontal lobe….Tapping along with music, either actually or just in your mind, involves the cerebellum’s timing circuits. Performing music - regardless of what instrument you play, or whether you sing, or conduct - involves the frontal lobes … for the planning of your behaviour, as well as the motor cortex …, and the sensory cortex, which provides the tactile feedback that you have pressed the right key on the instrument, or moved the baton where you thought you did. Reading music involves the visual cortex, in the back of your head in the occipital lobe. Listening to or recalling lyrics invokes language centres [of the brain].”

“At a deeper level, the emotions we experience in response to music involves structures deep in the primitive, reptilian regions of the [brain], and the amygdala - the heart of emotional processing in the cortex…”

Side note: since music utilizes and integrates so many different areas of the brain simultaneous, it is no wonder that individuals recognize the beat and lyrics to their favourite songs well into the progression of dementia (a neurodegenerative brain disorder) that primarily impacts our memory.

Dr. Levitin’s book continues:

“The brain’s … operations are distributed widely throughout. There is no single language center, nor is there a single music center. Rather, there are regions that perform component operations, and other regions that coordinate the bringing together of this information. Finally, we have discovered only recently that the brain has a capacity for reorganization that vastly exceeds what we thought before. This ability is called neuroplasticity, and in some cases, it suggests that regional specificity may be temporary, as the processing centers for important mental functions actually move to other regions after trauma or brain damage.”

Brain plasticity & connections

Side note: Brain plasticity (or neuroplasticity) – our brain’s ability to change itself in response to our experiences or the environment. Or as Dr. Levitin mentioned, our brains also rewire in response to brain damage or trauma, this likely offers part of the explanation of why music is still well perceived and appreciated even in the later stages of dementia (a neurodegenerative brain disorder). As dementia progresses, brain cells are dying and not functioning like they used to; but, music requires so many different brain regions (some that are involved with the anticipation of the beat, others connected to the lyrics, different brain regions that are linked to our emotional connection to a given song). The number of neural connections involved in our memory of music and our connection to a specific song is immense. Since there are so many brain cells involved as we listen to and appreciate music, they are likely more flexible and are better able to adapt in the face of the brain damage and brain cell death that occurs as dementia progresses.  

Dr. Levitin’s book continues:

“It is difficult to appreciate the complexity of the brain because the numbers are so huge they go well beyond our everyday experience… The average brain consists of 100 billion neurons [or brain cells]… This is a lot of neurons [brain cells], but the real power and complexity of the brain (and of thought) comes through their connections. Each neuron [brain cell] is connected to other neurons [brain cells] - usually 1000 to 10,000 others…As the number of neurons increases the number of possible connections grows exponentially.”

“The number of combinations becomes so large that it is unlikely that we will ever understand all the possible connections in the brain, or what they mean. The number of combinations possible - and hence the number of possible different thoughts or brain states each of us can have - exceeds the number of known particles in the entire known universe.”

Perception

As Dr. Levitin mentioned, the wiring in our brains is incredibly complex – and yet our perceptions of the world seem so effortless and simple. Dr. Levitin’s book continues:

“We are also under the illusion that we simply open our eyes and - we see. A bird chirps outside the window and we instantly hear. Sensory perception creates mental images in our minds … so quickly and seamlessly that it seems like there’s nothing to it. This is an illusion. Our perceptions are the end product of a long chain of neural events that give us the illusion of an instantaneous image.”

“Much of what we see and hear contains missing information. Our hunter-gatherer ancestors might have seen a tiger partially hidden by trees, or heard a lion's roar partly obscured by the sound of leaves rustling much closer to us. Sounds and sights often come to us as partial information that has been obscured by other things in the environment. A perceptual system that can restore missing information would help us make quick decisions in threatening situations. Better to run now than sit and try to figure out if those two separate, broken pieces of sound are part of a single lion roar.”

“The brain's task is to determine what the most likely arrangement of objects in the physical world is, given the particular pattern of information that reaches the sensory receptors - the retina for vision, the eardrum for hearing. Most of the time the information we receive at our sensory receptors is incomplete or ambiguous.”

Side note: Your brain is a master of efficiency. It would take too long for us to perceive every single sound in our environment or image in our visual field and put it together in order to aid perception. Because of this, our brain only needs to perceive part of what we hear or see and then it fills in the rest.

How do you hear?

Dr. Levitin answers in his book as follows:

“The eardrum is simply a membrane that is stretched across tissue and bone. It is the gateway to hearing. Virtually all of your impressions of the auditory world come from the way in which it wiggles back and forth in response to air molecules hitting it.”

“Sound is transmitted through the air by molecules vibrating at certain frequencies. These molecules bombard the eardrum, causing it to wiggle in and out depending on how hard they hit…But there is nothing in the molecules that tells the eardrum where they came from, or which ones are associated with which object. The molecules that were set in motion by the cat purring don't carry an identifying tag that says cat, and they may arrive on the eardrum at the same time and in the same region of the eardrum as a sound from the refrigerator, the heater…, and everything else.”

“How does the brain figure out, from this disorganized mixture of molecules beating against a membrane, what is out there in the world? In particular, how does it do this with music?”

“It does this through a process of feature extraction, followed by another process of feature integration. The brain extracts basic, low-level features from the music, using specialized neural [brain] networks that decompose the signal into information..”

Dr. Levitin has done a great job of explaining how music is perceived, but what about how music is remember. In his book he wonders, “How are memories of music different from other memories? Why can music trigger memories in us that otherwise seemed buried or lost? And how does expectation lead to the experience of emotion in music? How do we recognize songs we have heard before?”

Music & Memory

“Tune recognition involves a number of complex neural computations interacting with memory… When we perceive something, a particular pattern of neurons [brain cells] fire in a particular way… Although smelling a rose and smelling rotten eggs both invoke the olfactory system, they use different neural [brain] circuits. Remember, neurons [brain cells] can connect to one another in millions of different ways. One configuration of a group of olfactory neurons [brain cells] may signal “rose” and another may signal “rotten eggs.”…Remembering may simply be the process of recruiting the same group of neurons we used during perception to help us form a mental image during recollection. We re-member the neurons [brain cells], pulling them together again from their disparate locations to become members of the original club of neurons [brain cells] that were active during perception.”

“Have you ever been walking down the street and suddenly smelled an odor that you hadn't smelled in a long time, and that triggered a memory of some long-ago event? Or heard an old song come on the radio that instantly retrieve deep buried emotions associated with when that song was first popular? These phenomena get to the heart of what it means to have memories.”  

Multiple-trace theory

“According to the multiple-trace memory models, every experience is potentially encoded in memory. Not in a particular place in the brain, because the brain is not like a warehouse; rather, memories are encoded in groups of neurons that, when set to proper values and configured in a particular way, will cause a memory to be retrieved and replayed in the theatre of our minds… The more we access a memory, the more active become the retrieval and recollection circuits and the more [effortless] we are with the cues necessary to get at the memory.”

“A song playing comprises a very specific and vivid set of memory cues. Because the multiple-trace memory models assume that context is encoded along with memory traces, the music that you have listened to at various times in your life is cross-coded with the events of those times. That is, the music is linked to events of the time, and those events are linked to the music… Although certain songs may be associated with certain times of your life, they are not very effective cues for retrieving memories from those times if the songs have continued to play all along and you're accustomed to hearing them. But as soon as we hear a song that we haven't heard since a particular time in our lives, the floodgates of memory open and we're immersed in memories. The song has acted as a unique cue, a key unlocking all of the experiences associated with the memory from that song it's time and place.”

Documentary: Alive Inside

Side note: Have you heard about the documentary, “Alive Inside”? It talks about music’s capacity reawaken the human spirit. In the documentary, they demonstrate music’s ability to unlock memories from long ago and restore a deep sense of self to those suffering from it. If you haven’t seen it, and you are interested in learning more about the unique power that music has to connect with individuals – even those suffering from the very late stages of dementia - check out the documentary, “Alive Inside.” Click here for more information.

Dr. Levitin concludes his chapter on memory and music as follows:

Music & Emotions

“Memory affects the music-listening experience so profoundly that it would not be hyperbole to say that without memory there would be no music... Music is based on repetition. Music works because we remember the tones we have just heard and are relating them to the ones that are just now being played. Those groups of tones - phrases - might come up later in the piece in a variation ...that tickles our memory system at the same time as it activates our emotional centers. In the past 10 years, neuroscientist have shown just how intimately related our memory system is with our emotional system. The amygdala, long considered the seat of emotions in mammals, sits adjacent to the hippocampus, long considered the crucial structure for memory storage, if not memory retrieval. Now we know that the amygdala is involved in memory; in particular, it is highly activated by any experience or memory that has a strong emotional component.”

Conclusion

As you can tell from this episode, Dr. Levitin’s book is incredibly powerful and insightful. Buy your own copy today and read all of the additional nuggets he covers that did not make it into this episode.

For more information about “This is your Brain on Music: The Science of a Human Obsession” by Dr. Daniel J. Levitin, click here.