INTERVIEW WITH PROFESSOR RAY DOLAN FRS

Ray Dolan, FRS, professor of neuropsychiatry at UCL, is one of the pioneers of modern neurobehavioural research – he’s also a hiking partner and scientific muse to the novelist Ian McEwan. And so today I nipped out for a lunchtime coffee in his office overlooking Queen Square in central London, where he works at the neurological hospital.

I find a 50-something, warm, loquacious Irishman with endless patience to explain the intricacies of the brain to an arts graduate whose last exposure to the biological sciences was in O-level classes forty-odd years previously. I begin by explaining the nature of my problem: that I can sight-read music perfectly well, but the moment the sheet of music is taken away from me I really struggle – in fact, until recently I couldn’t play a note without sheet music in front of me. Dolan immediately reassures me. ‘You have a memory,’ he says firmly, ‘and the fact is that, at the end of that first month on the foothills, you were better at playing the Ballade. So something has gone in, something has happened. What the sheet is, essentially, is a cue and a lot of us need a cue to remember things, just something that will elicit the memory. So the music for you, as it’s written and in front of you, is clearly a guide, it’s a script, but it’s a cue as well. It’s eliciting memories that have been laid down.’

He proceeds to give me a lesson in memory. Broadly speaking, there are two types. ‘The first is what’s called explicit memory: and then there’s implicit memory. Explicit memory would be a memory that I can bring to mind and declare in some way. So the fact that yesterday morning I was in Potsdam. I can remember what I had for breakfast. I can remember waiting for the taxi to pick me up, going to airport. So that’s declarative memory.’

I’m already struggling. This sounds like three types of memory – implicit, explicit, declarative. Not two.

‘Well, there’s two types of explicit memory, so let me unpack it a little bit better. The memory I’m describing is what’s called an episodic declarative memory. In other words, I can retrieve the actual “me” embedded in the memory. There’s another type of memory which doesn’t require the “me” but which I can make explicit, which is “I know that Angela Merkel is the chancellor; I know that Joe Biden is the vice president of the US.” So I don’t have to think of “me” in that memory but I can bring it to consciousness.

‘So that’s two types of explicit, one is episodic, the other is semantic. You can bring them to your mind. I would say that that is a small compo- nent of the brain’s memory ability. The vast majority of your memory is implicit. It cannot be brought to consciousness, but it is there and we know it’s there for the following reasons. Based upon prior experience, your behavioural fluency is enhanced, and that goes from everything from walking, to riding a bicycle, to writing. These are all what’s called procedural memories, procedural skills. And the vast majority of memories are of that ilk. They’re acquired, you get a fluency in your behaviour consequent upon that prior experience that enables you to do things that you would not otherwise be able to do. There are many examples, things like skiing, for example. And all you need is to be back in the context for the memory to be elicited.’

One of the characteristics of implicit memory, he explains, is that it is not flexible. For example, ‘my [explicit] memory of being in Potsdam and knowing where the bridge is that divides east and west might be useful to me in the future, in some other context. If I was there and there was suddenly an outbreak of war, I’d know how to get across a bridge. So it is flexible, it can be deployed in other contexts. Procedural memories tend to be context-specific. So knowing how to ski or knowing how to play piano has no other application that we know of in other domains. It’s very domain- specific.’

Playing piano is a skill that falls under procedural memory. But Dolan makes it clear that ‘it’s not just the skill of playing the chords that’s proce- dural. The piece itself will be remembered, I think, largely as a procedural memory.’
I ask Dolan if these two different kinds of memory are located in different parts of the brain.

Explicit memory, he says, involves a part of the brain called the hippocampus, which is in the temporal lobes and plays an absolutely crucial role in helping us lay down day-to-day memories, such as recalling the specific instance of getting that phone call, of meeting that person, or seeing this thing on the street. How do we know this?

‘Well we know this because of a famous man called HM. He was a patient who suffered with epilepsy and he was operated upon in Montreal in the 1950s by somebody called Penfield. After he had the operation to relieve epilepsy, he seemed perfectly intact but he could not remember a thing that happened to him outside a temporal window of one minute. So he lived in a permanent one-minute here and now. What happened three minutes ago, five minutes ago, was gone, but what happened to him before he had the operation was preserved. He died, in fact, last year and he still thought Eisenhower was US president, and that TV was black and white.

‘Indeed, there is a famous musician, Clive Wearing, who has herpes simplex encephalitis, a rare viral infection that can affect your brain, which tends to take out this very part of the brain [the hippocampus]. Now the interesting thing is that, if I get Clive Wearing or HM, I could, in principle, teach them a new piece if they were musicians, assuming they have the basic skills. You could teach them a new piece of music and you could then teach them over a long period of time, or a not too long period of time, depending on how skilled they were before this happened. You could set them down at the piano and say, “Well could you play that new piece?” and they’d say, “No, I never heard it before.” But if you gave them a cue, it is almost certainly the case that they could just roll it all out because it is there as a procedural memory. So that tells you that procedural memory is a distinct type of memory and it also tells you that it is different parts of your brain that are involved in learning it.’

So where is procedural skill located? Dolan says that the striatum – a grouping of nuclei deep in the middle of your brain – and a structure at the back of the brain called the cerebellum are critical for procedural skills. ‘We know that from the type of work I do using non-invasive imaging to look at activity in the brain as you acquire a skill where those changes are expressed in the brain. But we also know it from pathologies in the brain, of which the most dramatic and tragic is Huntington’s disease.’

We then move on to discuss why some pianists can infuse a piece of music with emotion when they play, but others can’t. He mentions he’d met the pianist Angela Hewitt about six months ago. She told him that she taught some kids in China. It was a kind of a masterclass and she said some of them had trained since they were tiny, but that while they could play note perfect, they were unable to conjure emotion in the listener. ‘Why do you think that is?’ Dolan asks me.

I say that, in layman’s terms, I’d put it down to the life experiences and feelings for which we somehow manage to find an equivalence in music, a way of musically expressing accumulated experiences and emotions. A less individualistic culture might well create musicians who felt and expressed musically differently.

Dolan introduces another way of thinking about this. First, though, he has to lay out a global picture as to how the brain works.

‘Your brain has to assimilate all the sensory information that is coming in from the visual world around you, the noises outside, the dog barking in the park there. It’s a sensory bombardment and it’s continuous. So the amount of information is overwhelming. There is no computer in the world that could possibly process that. It’s just too rich. And how does your brain do it?

‘Well it does it by a very simple trick and it’s a trick, interestingly enough, that really goes back to the Enigma code. It has echoes of Alan Turing. How did they crack the Enigma code – because they still have the same problem: the problem of mass data and how you actually make sense of it?
‘And the way you make sense of it is that you have predictions. Your brain is predicting the sensory input. It makes predictions about what it’s expecting and those predictions help reduce the processing demands. So your brain does this on the basis of life experience, and on the basis of childhood experience – that surfaces tend to be hard, that a hot surface tends to burn. That’s how Turing worked [on Enigma] and it depends on a form of mathematics that goes back to a famous dissenting minister at the end of the eighteenth century called Thomas Bayes. He’s buried in the City of London. Thomas Bayes, it turns out, only published one paper – not in his lifetime – that was suddenly picked up by Laplace, a French mathematician who he has become the most important intellectual figure in how you can deal with complex information: his influence has suffused all of biology.’

I’ve lost the starting point of all this – the China question. My own brain is working hard to digest this absorbing personal seminar. I’m beginning to understand Ian McEwan’s fascination with the man and their habit of going off on hikes together, sometimes lasting days. But how, I ask Dolan, does all this help us to understand what might allow one pianist to move us when another can’t?

‘Well, when you acquire a skill, that skill is enacted out by you making predictions about the consequences of your actions. A lot of motor skills are also of that ilk. You’re making predictions of the consequences of your actions. And those predictions, they perfectly line up with the consequences so you don’t notice anything. It’s only when there’s a deviation that you notice. And that deviation in mathematical terms is called “surprise”. But I think that’s one of the things that good musicians do. They’re not aware of this in any technical sense, but a crucial thing is to bring elements of surprise into how you play it. People say there’s no improvisation in classical music. I’m sure there is, that’s what makes one musician different than the other.’

So a good pianist has this ability to provide ‘surprise’ and so stimulate emotion in the listener. But is there anything that distinguishes the brain of a great pianist from a mediocre one?

‘If you have to do a neuroscience dissection of great musicians,’ Ray says, ‘the one thing that they would have is great memories, and probably proce- dural memories.’ This allows them to learn a vast canon of music and then recall it easily when at the piano. What is crucial, though, is that they have the ability not to corrupt their procedural memory, so that ‘people who become the finest musicians are the people who can just let the procedural memory unfold without the anxiety and worry of trying to recall it explic- itly. I guess a lot of jazz musicians must operate at this level. They’ve learned scales over and over again and they get a cue from whatever is the particular structure.’

Dolan also thinks it very unlikely that a successful pianist would be able to recall any piece explicitly; that is, they might be able to play it, even without the music, but without the cue of the keyboard itself, they could not just sit down with pen and paper and tell you ‘that note follows that note, follows that note’. Indeed, according to Dolan, taking any procedural skill and trying to access it as an explicit memory can have problematic effects. He explains this with a story of his own.

‘I had somebody staying in my house and they called me up here [at the office] and they said “Listen we’re going out. Do we have to put the alarm on?” I said, “Yes” and they asked “What’s the code?” Now every night I just tap in the code, it started off as an episodic memory. I’d remember the code, 1901, but I had transformed it into a procedural skill. But when I was asked this over the phone I could not remember it. It was only there as a proce- dural skill. I struggled and struggled but it wouldn’t come. Now the inter- esting thing is that, that evening going to bed, I’m usually the last to bed so I tried to put in the code and I couldn’t do it. I had to go upstairs to my wife, embarrassingly, and say, “I’m really losing it. I can’t remember.” So that’s just an example of how they can occasionally corrupt. They can interfere with each other.’

At this point I mention the Artur Pizarro story – learning the Brahms second piano concerto on a long-haul flight to the Far East. What was going on there? Dolan isn’t sure the story can be true; but if it is, it presents a very interesting proposition. ‘Because if you read a piece on the plane for four, five, six hours, that’s not a procedural skill, unless you imagined that, as they are reading it, they are enacting it in their minds, the actual playing of it. That would be an interesting question to ask. Are they remembering it as they would remember a piece of poetry or a speech they’ve got to give? Or are they, as they are reading it, are they actually imagining themselves playing it, because that, I think you could argue, is transforming an input into a procedural skill. Some people are very good at that. People will offer you coaching for tennis where you do it in your mind first or they’d offer it for skiing that you didn’t have to go on to the slopes. Apparently there is evidence that you can become more skilled by just enacting it.’

Next, I ask him what he understood by the term ‘muscle memory’. He says there is no such thing. ‘Your muscles have no memory at all. That’s the first thing I’d say to you. If somebody has used that as a description of
what they experience, I would say it’s procedural memory. It is the elicita- tion of this memory that is not available to consciousness laid down as a pattern of activity.’

‘So, I’m sitting there repeatedly playing the same arpeggios, drumming, as I think of it, patterns into my fingers. But that’s a complete misunder- standing of what’s going on?’

‘Yes, it’s [only being drummed] into your brain. So when you play the first note of an arpeggio, the second note you’ve set up. That is the cue for you to complete it. It’s the cue that elicits that procedural skill. A lot of language acquisition is really of this ilk as well. So as a child, I learned Gaelic, and I learned an awful lot of it. I can say prayers in Gaelic and, occasionally, I can’t say them until I get a start. I might sometimes go on the internet and look up how to say the Our Father in Gaelic. But if I get the start of it I can just reel it off as a procedural skill. So a lot of it is getting those first elements, which is a bit like what is provided to you by having the music laid out in front of you.’

‘So the act of doing exercises might just be about improving your muscles?’

‘Yes. Your muscles can atrophy from lack of use and they can hypertrophy, get bigger and stronger, but there is no memory.’

‘Is there a bit of the brain that relates to your fingers?’

He has a model of a brain in his office and holds it up to illustrate what he’s saying.

‘In the cortex, there’s what’s called the motor strip, and behind it there’s what’s called the sensory cortex. You use your hand, because of our manual dexterity, more than you use your shoulder, so the hand takes up more geographical space [in the cortex]. And this seems to be something that can expand a little bit, at the edges of the hand representation and the surrounding areas that are represented adjacent to it. Let’s suppose you learn a new skill. What does happen is that the area [of the cortex] that is expressing the hand expands a little bit and the surrounding areas are squashed a little bit, so it’s like borders shifting. There seems to be a kind of a Darwinian prin- ciple that use and skills will expand the representation.’

‘Is that both in childhood and in adulthood?’ ‘More in childhood. The plasticity of the brain is greater in childhood.’ ‘But the hand bit of my brain could still grow a bit now if I played every day?’ ‘Yes, it could happen in adulthood as well. It’s not too late for you.’ I am encouraged by this exchange. My brain is still capable of stretching to these new challenges – ‘it’s not too late for you’: I’ll remember that. Ray fleshes it out with an example.

‘Let’s suppose we now decided we will get somebody who’s aged 50, never played the piano. You’re going to just lock them up in a castle somewhere. They’re told: “Only come out when you can play a very complex bit of Liszt. That was their goal, to Grade 8 standard. We measured their brain before they went in. Now the skill that they would be acquiring would be a procedural skill primarily. It would be expressed via the hands because they’re playing the piano. We measured their brain in an MRI scanner. If you acquire new skills you can’t grow more neurons, but what happens is the neurons sprout more tentacles, they develop more dendrax, and because of that sprouting we could show, at the end of the year, that the person’s brain has changed its configuration subtly but definitely, and that the part of the brain that represents the hand would be thicker.”

‘Dendrax?’

‘Dendrax. So if you imagine a neuron. That’s the cell body. It sends out something called an axon, but at the top of the neuron it has these little things that are called dendrax, which make connections with other neurons. So what happens with a new skill, when you’re learning the thing, is that the part of the brain that’s doing the learning sprouts out of the cell body new dendrax. How do we know this? We know it from experiments that have been done where people acquire a new skill. So if you learned to paint with your toes, for example, we could show that the part of the cortex that represents your toe expands a little bit and becomes a little bit thicker.’

Finally, I tell Dolan about why I feel my piano time helps my professional time. I hesitate to describe what it feels like – how it seems as if I’m using a different part of my brain when I’m doing my daily twenty minutes, and in some way it sets me up for the day. The chemistry has been altered. Does that make sense to him?

‘One of the things I do with my kids in half term,’ he tells me, ‘is to go skiing with them. I do this once a year with them. One of the things I notice when I ski is that I don’t think about other things, so all my anxieties and worries are gone out of the window. I think when you’re in that sort of mode, using that particular form of memory, it does largely suspend all the other bits. It’s very difficult for you to be worried about whatever a Guardian editor worries about, when you’re in that space. I think it does set you up for the day because you allow yourself to be without all the anxieties and worries and troubles. I think it’s not a conscious thing. I think it’s when you get into that space your brain can’t do anything else. You’re liberated from the tyranny of your explicit, you know, over-representational mind.’

And it is not just the brain that benefits from this ‘suspension’ while I’m playing. He thinks it relaxes me in other ways, gives my body a break. ‘Because although you might have anxieties, that’s not just something that exists in your head; it exists in your body. Your blood pressure is going up, your stress ions are going up, and playing music is a great way of suspending it. My wife, who usually plays the piano for an hour a day, does it, she tells me, for that very reason: she’s just in another world. She’s a breast radiolo- gist so she has lots of young women who come and they get very bad news and it’s terribly distressing, but she says she can suspend it that way.’

I’m charmed by the man and heartened by his description of how it all works and what it does for the spirit, soul and body – three words I’m sure he would never dream of using in such a context. In particular, the notion that the 56-year-old brain can certainly learn new tricks. I can almost feel the neurons and dendrax sprouting as I trip out of his office and head back to the tyranny of my explicit, over-representational day job.