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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Women on the edge: new films Jackie and Christine are character studies of haunted women

With their claustrophobic close-ups and desolate wide shots, both films are stunning portraits of life on the brink.

Jacqueline Kennedy and Christine Chubbuck may not have had much in common in real life – the former briefly the US first lady, the latter a put-upon television news reporter in the early 1970s in Sarasota, Florida – but two new films named after them are cut resolutely from the same cloth. Jackie and Christine are character studies of haunted women in which the claustrophobic close-up and the desolate wide shot are the predominant forms of address.

Both films hinge on fatal gunshots to the head and both seek to express cinematically a state of mind that is internal: grief and loss in Jackie, which is set mainly in the hours and days after the assassination of President John F Kennedy; depression and paranoia in Christine. In this area, they rely heavily not only on hypnotically controlled performances from their lead actors but on music that describes the psychological contours of distress.

Even before we see anything in Jackie, we hear plunging chords like a string section falling down a lift shaft. This is the unmistakable work of the abrasive art rocker Mica Levi. Her score in Jackie closes in on the ears just as the tight compositions by the cinematographer Stéphane Fontaine exclude the majority of the outside world. The Chilean director Pablo Larraín knows a thing or two about sustaining intensity, as viewers of his earlier work, including his Pinochet-era trilogy (Tony Manero, Post Mortem and No), will attest. Though this is his first English-language film, there is no hint of any softening. The picture will frustrate anyone hoping for a panoramic historical drama, with Larraín and the screenwriter Noah Oppenheim irising intently in on Jackie, played with brittle calm by Natalie Portman, and finding the nation’s woes reflected in her face.

Bit-players come and go as the film jumbles up the past and present, the personal and political. A journalist (Billy Crudup), nameless but based on Theodore White, arrives to interview the widow. Her social secretary, Nancy Tuckerman (Greta Gerwig), urges her on with cheerleading smiles during the shooting of a stiff promotional film intended to present her warmly to the public. Her brother-in-law Bobby (Peter Sarsgaard) hovers anxiously nearby as she negotiates the chasm between private grief and public composure. For all the bustle around her, the film insists on Jackie’s aloneness and Portman gives a performance in which there is as much tantalisingly concealed as fearlessly exposed.

A different sort of unravelling occurs in Christine. Antonio Campos’s film begins by showing Christine Chubbuck (Rebecca Hall) seated next to a large box marked “fragile” as she interviews on camera an empty chair in which she imagines Richard Nixon to be sitting. She asks of the invisible president: “Is it paranoia if everyone is indeed coming after you?” It’s a good question and one that she doesn’t have the self-awareness to ask herself. Pressured by her editor to chase juicy stories, she goes to sleep each night with a police scanner blaring in her ears. She pleads with a local cop for stories about the darker side of Sarasota, scarcely comprehending that the real darkness lies primarily within her.

For all the shots of TV monitors displaying multiple images of Christine in this beige 1970s hell, the film doesn’t blame the sensationalist nature of the media for her fractured state. Nor does it attribute her downfall entirely to the era’s sexism. Yet both of those things exacerbated problems that Chubbuck already had. She is rigid and off-putting, all severe straight lines, from her haircut and eyebrows to the crossed arms and tight, unsmiling lips that make it difficult for anyone to get close to her. That the film does break through is down to Hall, who illuminates the pain that Christine can’t express, and to the score by Danny Bensi and Saunder Jurriaans. It’s perky enough on the surface but there are cellos sawing away sadly underneath. If you listen hard enough, they’re crying: “Help.” 

Ryan Gilbey is the New Statesman's film critic. He is also the author of It Don't Worry Me (Faber), about 1970s US cinema, and a study of Groundhog Day in the "Modern Classics" series (BFI Publishing). He was named reviewer of the year in the 2007 Press Gazette awards.

This article first appeared in the 19 January 2017 issue of the New Statesman, The Trump era