‘Seeing’ Language through Neurolinguistics

What happens in a person’s head when they hear speech or say something themselves? How does trauma and disease impact a person’s speech capabilities, and can we really help people who have certain medical conditions? Questions like these concern the life of language in the human brain, and this is exactly what researchers in the HSE Neurolinguistics Laboratory are currently studying.

100% of the Brain

‘People sometimes ask me, “Where is language housed in the brain?” to which I answer, “Everywhere,”’ comments linguist Olga Dragoy, who is the Head of the Neurolinguistics Laboratory. ‘For some time, newspapers were filled with information about how we only use 3% of our brains, while the rest is just on reserve. When I was a student, one of my classmates asked our neuroscience professor in Italy this very question, and he said fine, let’s cut away 97% of your brain and see how well you function. Language is a product of the interaction between various parts of the brain.’

The HSE Neurolinguistics Laboratory, which is made up of linguistics, psychologists, speech pathologists, physicists, and many HSE students, researches how the brain and language work together at the interface of linguistics and medicine. The laboratory also has a clinic – the Centre for Speech Pathology and Neurorehabilitation – and works with other clinics and institutions as well, including the Burdenko Neurosurgery Institute.

The laboratory began its work in 2008 when Olga Dragoy returned from Europe after completing her master’s in clinical linguistics and Maria Ivanova, a clinical psychologist who now works in the laboratory, returned from the U.S., where she completed her PhD. The researchers met in the Centre for Speech Pathology and Neurorehabilitation, where they also became acquainted with HSE neuropsychologist Anatoly Skvortsov, who invited them to work in a neuropsychology research group created within the HSE School of Psychology.

‘In 2013, we got the idea to create a separate neurolinguistics research laboratory as part of the philology faculty (now the School of Philology), and exactly one year later, we received a grant to launch an international laboratory. April 1^st is actually our three-year anniversary,’ Olga Dragoy notes.

In Search of a ‘Tail’

The laboratory’s main task is to conduct research on adults with various brain conditions that affect speech (aphasia). The researchers study how the speech disturbances that occur on the outside (identified with the help of linguistic tests) are connected with specific defects inside the brain.

These defects might stem from a stroke or a head injury. To study this, the laboratory has developed special tests, one of which is called RAT, or the Russian Aphasia Test. This test allows researchers to see exactly which specific defects are present in a person’s speech. Additionally, with the help of an MRI, researchers are able to see not only which portion of the cerebral cortex the defect is in, but also the ‘tail’ of a defect – nerve pathways that used to lead to a different part of the brain, but are now also damaged.

‘It’s important that we look at all portions of a damaged brain as a whole. This allows us to see how the brain builds new connections in place of old by using healthy sections of the brain instead of damaged ones,’ Olga Dragoy explains. ‘The MRI shows when the brain activates, which allows us to see where a person’s speech function has “gone” to. In addition, by comparing data from the MRI with the results of our language tests, we are able to understand how successfully the speech function has been reorganised. Last year, we developed a special speech localizer. You complete a speech task under an MRI, and we determine which sections of the brain are activated during the task. Our research also helps patients with aphasia select the best speech therapy plan,’ she adds. 

Maria Grabovskaya, fourth-year student in the Fundamental and Computational Linguistics programme and junior researcher in the laboratory

‘I’m graduating this year, and my thesis is a study on language disorders in patients who experienced a stroke or head trauma that caused aphasia. This condition results in a person’s inability to understand not only grammar and phonetics, but also complex phrases and discourse.

‘Our country does not yet have a text that has, first, been tested on both neurologically healthy individuals and people with various brain conditions, and second, helps us to understand the associated defects. This is why my academic supervisor Yulia Akinina and I are currently working on adapting an analogous Italian text that helps us understand different speech defects. The difficulty lies in the fact that a portion of the examples (stimuli) on which the text is based can be translated word for word practically, while others can’t. This is why for several instances, we cannot simply translate the text; we have to create our own stimuli that correspond with Russian, not Italian, reality. The resulting assessment will be tested in real life soon; this spring, we’ll run the test on healthy individuals before testing it on individuals with brain disorders later in the fall,’ Maria says. 

Awake Brain Surgery

The laboratory also works with patients who have brain tumours and are awaiting brain surgery.

‘Unlike a stroke, which instantly destroys part of the brain, a tumour can take years to grow, giving the brain time to compensate and reorganise,’ Olga Dragoy notes. ‘Sometimes, an enormous tumour can “live” in parts of the brain used for speech, but because the tumour took so long to grow, the brain has found a way of adapting, which is why we don’t see any sort of speech defect. Together with our colleagues from the Burdenko Institute, we are studying exactly how this adaptation occurs, as well as which parts of the brain are involved. Because if these parts are damaged during surgery, you can lose speech altogether,’ she adds.

During these operations, the patient is first given general anaesthesia (put to sleep), trepanation is performed, and the person is taken off the anaesthesia (woken up). While he or she is awakening, we work with a team of doctors to map speech

Russia’s Burdenko Neurosurgery Institute is one of the few locations in Russia that carries out some of the most advanced brain operations being performed today, specifically awake brain surgery. Staff from the HSE Neurolinguistics Laboratory assist in the operations.

‘During these operations, the patient is first given general anaesthesia (put to sleep), trepanation is performed, and the person is taken off the anaesthesia (woken up). While he or she is awakening, we work with a team of doctors to map speech,’ Olga Dragoy adds. ‘The patient carries out speech tasks (names images, finishes sentences, repeats words, etc.), during which the surgeon uses low-level electrical brain stimulation on certain parts of the brain, which is enough to block the speech function. If the patient stops carrying out a speech task or makes certain mistakes when a certain area of the brain is stimulated, we know that this particular part of the brain is critical for speech. Such testing allows us to localize speech zones in various sections of the brain so a doctor can remove an entire tumour without touching the parts of the brain being used in speech,’ she concludes. 

Valeria Tolkacheva, third-year student in the Fundamental and Computational Linguistics programme and junior researcher in the laboratory

‘I first read about the laboratory in an interview with Olga Dragoy, but I wasn’t able to get in right away, as I didn’t get up to speed on the topic fast enough. But after my first year, I went to the Summer Linguistics School that the lab organises, after which Olga offered me a position.

‘Our patients are people with brain tumours located close to the language centre – that is, in the temporal and frontal lobes. In the lab, we developed a special test for these kinds of operations. The surgeon stimulates the cerebral cortex, and we carry out a test while the patient is still conscious. My academic supervisor Anna Chrabaszcz and I take part in these kinds of operations once or twice a week.

‘For me, working in the lab is a way of realising my childhood dream of working in medicine, and this won over my passion for languages and linguistics. But as it turns out, I can combine all of these things by working in the Neurolinguistics Laboratory. I’m working on something that’s truly at the interface of medicine, psychology, and linguistics, and I’ve already gone to several international conferences to present the results of our research. The main thing, I believe, is that my intellectual effort helps people – it helps doctors perform an operation, and it helps patients maintain speech. When you see that a patient is able to speak and that his or her life improves as a result, this inspires you, and you understand that you’re doing something good and effective,’ Valeria notes.

Left-handed, Right-handed, and Ambidextrous

But the laboratory works with more than just people with brain disorders. For example, the lab researches the lateralization of speech in the brain of individuals without any disorders. Brain lateralization refers to the linkage of psychological functions during the growth of an organism with left and right hemispheres.

‘We research where the speech function is located for left-handed, right-handed, and ambidextrous individuals – in the right or left hemisphere, or possibly in both,’ Olga explains. ‘It’s interesting to look at nonstandard speech zone organisation. For example, a person can be right-handed but have a genetic predisposition toward left-handedness because relatives in a certain generation were left-handed. This increases the chance that his or her speech will, at least partially, be located in the right hemisphere. And if this person has a stroke in the left hemisphere of the brain, then their main language centre won’t be touched, and aphasia will not occur,’ she concludes.

Tatiana Bolgina, third-year student in the Fundamental and Computational Linguistics programme and junior researcher in the laboratory

‘I found out about the Neurolinguistics Laboratory during my first year when I had to decide on the subject of my term paper. I ultimately worked on the impact of control functions like memory and attention on one’s understanding of lies and irony during my first and second year. This year, however, I started a new project in which I use MRIs to study the location of language centres in right-handed, left-handed, and ambidextrous individuals. My goal in the current stage of the project is to test out a speech localizer that allows you to determine where in the brain the areas responsible for speech are located.

It turns out, I myself am a rare example of when language is distributed bilaterally in the brain – both hemispheres are activated during speech

‘We have two important zones in the brain that are responsible for speech. One is located in the frontal lobe and involves the famous Broca area that activates during speech production. The other zone is in the back of the temporal lobe and is responsible for processing signals – that is, understanding speech. For right-handed people, the language centre is typically located in the left hemisphere of the brain, while it was believed that this centre should be in the right hemisphere for left-handers. But it’s just not that simple. Data from MRIs (red and yellow spots that show which areas of the brain are active when someone carries out different speech tasks) show that left-handers’ language centre is quite often located in the right hemisphere, but the centre could be in the left hemisphere like with righties, and sometimes it can be bilateral – that is, in both the left and right hemispheres.  

I’m a forced right-hander, and it was fun to do the experiment myself before testing it on others. It turns out, I myself am a rare example of when language is distributed bilaterally in the brain – both hemispheres are activated during speech,’ Tatiana notes.

Language and Time

Another area the laboratory is working on relates to how language is organised in the brains of native speakers of certain languages. Olga Dragoy stresses that this does not concern trying to determine which languages are more advanced. ‘There are no poor or structurally underdeveloped languages; each language is an incredibly rich system. If a language has five vowels, for example, this doesn’t mean it has a weak structure. The language might have complex syntax, inflection, or agreement, for instance. There are studies that show that a person’s brain function is enriched by the qualities of the language he or she speaks. For example, natives of sign language have better developed spatial thinking. Deaf people speak using signs, and for them the space of gesticulation is a mental space that they work in,’ Olga notes.

When a person who writes from left to right, like we do in Russian for example, hears a verb in the past tense, their eyes make a tiny movement to the left (like looking backwards)

Researchers in the lab are currently looking for differences in how the brain works for native speakers of Russian, Japanese, and Hebrew. ‘The working hypothesis is this – depending on which direction you write in, people map verb tenses differently in their mental space,’ Olga says. ‘We assume that in our (Russian) mental space, time unfolds from left to right: past, present, and future. In our experiment, a subject is presented with a verb in the past or future tense (wrote/will write), and we record his or her eye movements. When a person who writes from left to right, like we do in Russian for example, hears a verb in the past tense, their eyes make a tiny movement to the left (as if looking backwards), and when it’s in the future tense, they look to the right. In Hebrew, they write from right to left, and we want to see if native Hebrew speakers demonstrate the exact opposite reaction compared to native Russian speakers. But Japanese speakers write one of two ways – either from left to right or in the classical tradition of top to bottom. Does this mean the effect will be “caught” on the vertical axis, or will it take place diagonally? We hope to have answers to these questions very soon,’ Olga concludes. 

Nikita Zmanovsky, second-year student in the Fundamental and Computational Linguistics programme and junior researcher in the laboratory

‘I’ve wanted to be a scientist since childhood. Even in elementary school, I begged my parents for a microscope. I would rip off leaves from our houseplants and flowers and look at them. On top of biology and natural science, I also became interested in linguistics in middle school.

‘My last two years of school, I was in the biology programme of Tyumen State University’s gymnasium. I thought I’d go to Moscow State University for theoretical and applied linguistics, but then I read an interview with Olga Dragoy and learned about HSE’s neurolinguistics laboratory. I wrote Olga and told her how much I wanted to study neurolinguistics. She wrote me back and told me about the options that exist in Russia today as well as what her laboratory does, and as a result, I decided I wanted to study at HSE. Plus, since I won a medal at the Russian Language Olympiad, I didn’t need to take entrance exams.

The brain will react very differently to the sentences “grandma made porridge out of concrete and butter” and 'grandma made porridge out of oatmeal and butter'

I came to Moscow in September when school started, and this is also when I began working in the laboratory. I was given a project in which we studied speech using electroencephalography, which seems like one of the most “hands-on” neurolinguistics methodologies. You put a cap with 128 electrodes on the subject, turn a button, and in parallel hold a discussion with them. I end up meeting people, acquiring practical experience, and doing research all at the same time. This is a very advanced methodology that requires knowledge in a variety of scientific areas, such as physiology, physics, linguistics, mathematics, and programming.

We are studying how the brain reacts differently to varying types of mistakes in a sentence – semantic mistakes, syntactic errors, etc. As one example, the brain will react very differently to the sentences “grandma made porridge out of concrete and butter” and “grandma made porridge out of oatmeal and butter.” And this is exactly what excites me about research in the field of neurolinguistics – the language we’ve gotten used to viewing as completely intangible actually has a physiological side. It’s linked to something material. It’s something you can touch and something you can count,’ Nikita concludes.

Lyudmila Mezentseva, HSE News Service