杏吧原创

Most of us already know that music can have a profound effect on mind and body. Consider the feeling of empowerment when you slip on some headphones and go for a run, the rush of nostalgia you get from hearing your favourite song from your childhood or the joy of singalongs in the car 鈥� music moves us, literally and figuratively. It can make us happy when we are sad, sad when we are happy, as well as make us dance, laugh and relax.

But what if it could do more than that 鈥� what if music had the power to actually heal us? In his new book Music as Medicine: How we can harness its therapeutic power, neuroscientist explains why he believes it can.

The idea that music is medicine isn鈥檛 new 鈥� there is evidence that shamans and healers in cultures across the world have used music, especially drumming, to treat people for thousands of years.

Only in recent decades, however, has science offered a rational basis for music as a mechanism for healing, demonstrating that it has a direct and measurable impact on our nervous system.

Advances in neuroimaging coupled with more rigorous experimentation drawing on music theory, cognitive psychology and physiology suggest that music can be useful in aiding everything from Parkinson鈥檚 disease to Alzheimer鈥檚 and depression.

Levitin spoke to New 杏吧原创 about these health benefits, and how music might be added to our medical toolkit.

Linda Rodriguez-McRobbie: It seems intuitive that music can affect the body, but what has improved our recent understanding of its influence on our health?

Daniel Levitin: Historically, we have had little good evidence for music as medicine. We had a lot of stories. Now we have a lot more looking at the neurological processes underlying our response to music, looking at the overlap between music and non-musical activity in the brain, and testing the therapeutic effects of music.

We have also come to understand the importance of movement to cognition 鈥� we call that 鈥渆mbodied cognition鈥�. It鈥檚 the idea that cognition is fundamentally shaped by the body鈥檚 interaction with the physical world, rather than being solely a product of abstract mental processes.

So listening to music is a more full-bodied experience than just what happens in your ears?

That鈥檚 exactly right. I did an event with Stewart Copeland from The Police, and he articulated it as 鈥渕usic is the only art form that makes you want to twitch and wiggle your body鈥�. Few people are standing in the Louvre looking at the Mona Lisa and wanting to dance to it. But music triggers activity between our ears and our brain鈥檚 motor system.

Meaning we can鈥檛 help but move to music?

One thing I鈥檝e seen in my own neuroimaging studies is that even when people in a scanner who are listening to music are explicitly instructed not to move, the parts of their brains that would be planning and coordinating movement are still active. We have between the music perception areas of the brain and the motor planning and movement parts of the brain. It鈥檚 not merely the rhythm of music that drives this, because on movement; it is something about the totality, the gestalt of music that causes this.

What do we know about how different kinds of music impact us?

At a really rudimentary level, music with a deep rhythm like James Brown 鈥� as opposed to, say, [18th-century composer] Domenico Scarlatti 鈥� is going to make you want to move. Listening to different styles of music elicits different strengths of activity in the auditory-movement circuits. For instance, one study showed that reggae evoked the highest activity in this area compared with folk, electronic and classical music.

But our tastes are very subjective. How it affects you depends on what the music means to you, whether or not you like it. So, when we talk about medicinal effects of music, it鈥檚 not that Joseph Haydn is going to cure the common cold, Joni Mitchell is going to cure depression and [swing-era bandleader] Cab Calloway is going to cure Alzheimer鈥檚. It鈥檚 got to be what it is that you like, because your in music鈥檚 health effects.

Can you tell me more about these effects and the mechanism behind them?

There鈥檚 not a single mechanism. If you have a bacterial infection, you take an antibiotic, but if you have arthritis, the antibiotic won鈥檛 work. The mechanisms of action of particular drugs need to be directed at particular ailments. So, to expand the analogy, not all music makes you want to move and not all movement is curative or 鈥渉ealing鈥�.

But when music gets you dancing, it鈥檚 aerobic and boosts the mood-stabilising hormone serotonin. Playing an instrument can help hand-eye coordination, which is neuroprotective because it .

So could music help with conditions that affect the brain, like Parkinson鈥檚?

When it comes to Parkinson鈥檚 or other movement disorders, such as motor neuron disease, where there is progressive degeneration of nerve cells in the brain and spinal cord, music helps us synchronise our movements. It can also help us , which people with Parkinson鈥檚 can otherwise find difficult to do.

We think this is because music with a strong rhythm in synchrony. It鈥檚 not just the rhythm of the music that is responsible for this. We speculate that music is because it is engaging and emotional and also has a social aspect to it. have shown how different features of music contribute to this synchronisation of brain responses, each is like a strand of a rope that works together to promote synchronisation.

I鈥檝e heard that music can also help people who have lost the ability to speak after a stroke

Yes, you can use music to cure aphasia, loss of speech 鈥� that鈥檚 a different mechanism entirely. Music circuits can be preserved in the face of damage to the speech centres, and so you can , and, eventually, the brain rewires itself so that you can say it without singing.

Music can help recontextualise experiences reducing symptoms of depression

You mention in your book that music can even help people with Alzheimer鈥檚. How?

With Alzheimer鈥檚, it鈥檚 something completely different again. Music seems to help you access old memories that you have lost touch with. Everything that has happened to you, every experience, is encoded in memory somewhere. Memories also encode the context surrounding an event. If there鈥檚 a particular song that you heard and it was associated with a particular span of time 鈥� like that summer you turned 13 years old 鈥� the music becomes associated with all the other events of that time: your friends, the movies you saw, the books you read and so on.

Alzheimer鈥檚 destroys areas of the hippocampus, which is where we believe memories are indexed, if not stored. We believe that , which helps you access memories that are preserved but difficult to locate.

Does music also help with conditions like depression?

Yes, it can have a . Music helps you recontextualise your experiences. As an example, we know that when people 鈥減ull out鈥� a memory, the mood they are in can such that when it gets 鈥減ut back鈥� into storage, it can take on a different valence. In this way, calm music can help to make a traumatic memory less powerful, and can make a memory less fearful.

You have written that music also engages the brain鈥檚 default mode network, allowing us to get into a trance-like state. How does that benefit us?

It鈥檚 easier to understand it when you contrast that state with our regular mode of thinking, where we use 鈥渢he executive attention network鈥�. This is where you are trying to focus on something and consciously guiding your thoughts. The default mode network is the opposite 鈥� you鈥檙e not in control of your thoughts, it鈥檚 like a daydream state. These two networks function like a seesaw, a teeter-totter, because one is active when the other isn鈥檛.

It takes an act of will, of deliberate intervention, for us to focus on something. That focusing comes with a biological, metabolic cost in the form of spent glucose, the brain鈥檚 fuel. The default mode helps to , in a similar way that sleep does.

We also think that some kind of physical healing happens while in the default mode. The brain typically repairs damaged cells while you are asleep. We think this is partly because acetylcholine and other chemicals, some of which are involved in the immune system, set up a kind of programme for cellular housekeeping. We don鈥檛 know for sure, but it seems as though this kind of housekeeping can happen when you鈥檙e in the default mode, too.

Music engages your default mode network and therefore gives your body and brain a chance to reset.

We know that people have emotional connections to the music that is right for them, but can, say, listening to calming sounds like water make you feel better?

Sounds of nature that aren鈥檛 threatening 鈥� like a river flowing rather than a hurricane 鈥� those tend to be calming. Music with a slow tempo and stepwise motion also tends to be calming. Most people wouldn鈥檛 find distorted electric guitar music calming, but there are some people that will, there鈥檚 always going to be individual differences. Why some songs are calming and others are not is an area of active research that we are working on.

That said, none of the playlists that are on the commercial services for relaxing music are chosen by scientists. They鈥檙e just a bunch of people saying this relaxes me, so there鈥檚 no science behind them.