Ballet dancers’ brains adapt to stop them going dizzy

Years of training in “spotting”, the technique of quickly and repeatedly bringing your gaze to two specific points in front and behind you, certainly helps, but new research suggests that the brain’s ability to adapt plays a powerful role.

If you’ve ever tried spinning in circles while looking up to the sky, you’ll know the accompanying dizziness that can follow. But what stops ballet dancers, who pirouette endlessly for a living, from falling into each other like a set of dominoes?

Years of training in “spotting”, the technique of quickly and repeatedly bringing your gaze to two specific points in front and behind you, certainly helps, but new research suggests that the brain’s ability to adapt plays a powerful role. And it could help better treat and diagnose people who suffer from chronic dizziness.

Neuroscientists at Imperial College London recruited 29 female ballet dancers and spun them around in a chair in a dark room. When the chair was stopped, the dancers were asked to turn a lever to indicate how quickly they still felt they were spinning. This measured their perception response to dizziness. Eye reflexes – the quick flicking of the eyes from moving around rapidly – were also measured. In normal people, these two responses correlate well, but in the dancers there appeared to be an uncoupling: while their eye reflexes kept going, their perception response fell.

A group of 20 female rowers, who were similar in age and fitness, were also recruited as a control group. Brain scans were then taken to analyse the brain structures of all the individuals.

Powerful resistance

In cases of chronic dizziness, tests are usually taken of the vestibular organs in the inner ear. These fluid-filled organs use tiny hairs to sense the movement of the fluid, which in turn send signals to the brain. The continued movement of fluid explains one of the reasons you can continue to feel dizzy after you’ve stopped moving. But this doesn’t go far enough to explain dizziness in chronic suffers, said Barry Seemungal, co-author of the study, published in Cerebral Cortex.

“We measured sensation perception and eye reflexes and found dancers were much more resistant to non-dancers,” he said. “In the rowers, sensation correlated very well to reflexes, but in dancers the two were not correlated – they had de-coupled. In a person with chronic dizziness, the duration of their perceptual response is much longer; there’s a disproportionately higher reaction compared to a dancer who shows powerful resistance.”

An MRI scan then looked at the amount of grey matter (the bit that calculates) and the white matter (the part of the brain that makes connections) in the cerebellum. This also threw up differences between dancers and non-dancers.

“A statistical comparison between brain structures showed that in dancers an area of the cerebellum was smaller than in the rowers. This part of the brain also known to be involved in processing signals from the ear. And the more experienced the dancer, the smaller it is. The cerebellum can process signals that are then sent to areas of the brain linked to perception. In dancers it reduces the flow of signals – it acts like a gate.”

The researchers then looked at the cerebral cortex, which is associated in perception, and found stronger white matter in the control group. “More white matter means you’re more likely to be dizzy – in dancers we didn’t see it,” Seemungal said.

Seeing is believing

So how can these findings help people with chronic dizziness? For a start, we now have recognition that the brain is the organ that controls balance and, crucially, that it’s able to adapt.

“Traditional testing considers the ear as the organ of balance,” Seemungal said. “I’m a neurologist so I consider it as the brain.”

“The brain takes in lots of different information to make an assessment and compensates if it needs to. The ear is one source, vision is another. If you hear a noise to the right and move your head to look at it, your brain combines the estimates and places greater weight on the more reliable, in this case the eye.”

“But vision can be ambiguous – for example when you’re sat on a train and another one moves and you think you’re the one moving. As a general principle the brain prioritises visual motion over vestibular organs [the ear]. Another example is the ventriloquist’s doll, it combines the auditory and visual inputs but relies more on the visual so you think it’s the doll that’s talking.”

“If your vestibular organs aren’t working well, your brain won’t trust them and even trivial visual stimuli can trigger a dizzy sensation. But traditional testing relies on testing the vestibular organs, which might indicate nothing is wrong.”

People with chronic dizziness can be treated for underlying causes but also longer-term physio treatment. Depending on the form of the condition, this can include exposing them to self-motion (the swaying we all do but don’t notice if we don’t suffer from dizziness) and visual motion to get the brain more habituated.

One lucky find (for the researchers anyway) was that one of the dancers involved in the study later went on to develop chronic dizziness. This enabled the team to test her against their original findings. They found that although her reflex functions had remained the same, her perception response had become stronger.

Professor Nicky Clayton, a Professor of Comparative Cognition at Cambridge and Scientist in Residence at Rambert, the contemporary dance company, said: “As a dancer you learn tricks that allow your body to move in very flamboyant ways but without losing control. One of the tricks I learned was that when you get that sense of spinning, you use your core muscles to pull up; and that you’re disengaging with that feeling of fluidity and creating a stabilising energy.

She added: “Dancers think in very abstract ways … The way in which the brain talks to the cognitive system, whether through its plasticity or psychologically, is more than just spotting. Spotting helps you to focus but it’s not the only thing.”

Simon Lloyd, an ENT specialist, said: “The tests could potentially be useful because at the moment we have no effective way of testing how well parts of the balance system within the brain are working. Testing this would also allow us to measure how people are responding to treatment.”

The Conversation

This article was originally published at The Conversation. Read the original article.

Dancers of Cuba national ballet perform during a rehearsal for Swan Lake in Madrid in 2009. Photo: AFP/Getty Images

Jo Adetunji is the commissioning editor for health and medicine at The Conversation UK.

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Don’t worry, Old Etonian Damian Lewis calls claims of privilege in acting “nonsense!”

The actor says over-representation of the privately educated at the top of acting is nothing to worry about – and his many, many privately educated peers agree.

In the last few years, fears have grown over the lack of working class British actors. “People like me wouldn’t have been able to go to college today,” said Dame Julie Walters. “I could because I got a full grant. I don’t know how you get into it now.”

Last year, a report revealed that half of Britain’s most successful actors were privately educated. The Sutton Trust found that 42 per cent of Bafta winners over all time were educated independently. 67 per cent of British winners in the best leading actor, actress and director categories at the Oscars attended fee-paying schools – and just seven per cent of British Oscar winners were state educated.

“That’s a frightening world to live in,” said James McAvoy, “because as soon as you get one tiny pocket of society creating all the arts, or culture starts to become representative not of everybody but of one tiny part. That’s not fair to begin with, but it’s also damaging for society.”

But have no fear! Old Etonian Damian Lewis is here to reassure us. Comfortingly, the privately-educated successful actor sees no problem with the proliferation of privately-educated successful actors. Speaking to the Evening Standard in February, he said that one thing that really makes him angry is “the flaring up recently of this idea that it was unfair that people from private schools were getting acting jobs.” Such concerns are, simply, “a nonsense!”

He elaborated in April, during a Guardian web chat. "As an actor educated at Eton, I'm still always in a minority," he wrote. "What is true and always rewarding about the acting profession is that everyone has a similar story about them being in a minority."

Lewis’s fellow alumni actors include Hugh Laurie, Tom Hiddleston, Eddie Redmayne – a happy coincidence, then, and nothing to do with the fact that Etonians have drama facilities including a designer, carpenter, manager, and wardrobe mistress. It is equally serendipitous that Laurie, Hiddleston and Tom Hollander – all stars of last year’s The Night Manager – attended the same posh prep school, The Dragon School in Oxford, alongside Emma Watson, Jack Davenport, Hugh Dancy, Dom Joly and Jack Whitehall. “Old Dragons (ODs) are absolutely everywhere,” said one former pupil, “and there’s a great sense of ‘looking after our own’." Tom Hollander said the Dragon School, which has a focus on creativity, is the reason for his love of acting, but that’s neither here nor there.

Damian Lewis’s wife, fellow actor Helen McCrory, first studied at her local state school before switching to the independent boarding school Queenswood Girls’ School in Hertfordshire (“I’m just as happy to eat foie gras as a baked potato,” the Telegraph quote her as saying on the subject). But she says she didn’t develop an interest in acting until she moved schools, thanks to her drama teacher, former actor Thane Bettany (father of Paul). Of course, private school has had literally no impact on her career either.

In fact, it could have had an adverse affect – as Benedict Cumberbatch’s old drama teacher at Harrow, Martin Tyrell, has explained: “I feel that [Cumberbatch and co] are being limited [from playing certain parts] by critics and audiences as a result of what their parents did for them at the age of 13. And that seems to me very unfair.”

He added: “I don’t think anyone ever bought an education at Harrow in order for their son to become an actor. Going to a major independent school is of no importance or value or help at all.” That clears that up.

The words of Michael Gambon should also put fears to rest. “The more Old Etonians the better, I think!” he said. “The two or three who are playing at the moment are geniuses, aren’t they? The more geniuses you get, the better. It’s to do with being actors and wanting to do it; it’s nothing to do with where they come from.”

So we should rejoice, and not feel worried when we read a list of privately educated Bafta and Oscar winners as long as this: Chiwetel Ejiofor (Dulwich College), Emilia Clarke (St Edward’s), Carey Mulligan (Woldingham School), Kate Winslet (Redroofs Theatre School), Daniel Day-Lewis (Sevenoaks School, Bedales), Jeremy Irons (Sherborne School), Rosamund Pike (Badminton), Tom Hardy (Reed), Kate Beckinsale (Godolphin and Latymer), Matthew Goode (Exeter), Rebecca Hall (Roedean), Emily Blunt (Hurtwood House) and Dan Stevens (Tonbridge).

Life is a meritocracy, and these guys were simply always the best. I guess the working classes just aren’t as talented.

Anna Leszkiewicz is a pop culture writer at the New Statesman.

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