Foreign Languages Slow Down Brain Ageing
Medical advances are causing a gradual increase in average life expectancy. However, this comes at a price, as the number of cases of dementia and other neurodegenerative diseases grows with age. Researchers from HSE University (Russia) and Northumbria University (UK) have found that bilingualism can slow down and mitigate the course of age-related changes in the human brain. The study was published in Frontiers in Psychology.
The human brain begins to perform worse with age: overall information-processing speed decreases, short-term and episodic memory deteriorates, and control over language skills, executive, and visuospatial functions declines. This process is called ‘cognitive ageing’. At the neuronal level, it manifests itself through anatomical changes in the grey and white matter in specific brain regions.
However, the speed at which aging occurs varies and depends on a person's cognitive reserve—the brain's ability to cope with the effects of age-related brain damage and maintain optimal performance. This reserve is built up over the course of a person’s life, as the brain strengthens neural networks in response to various external stimuli. The more complex the neural networks are, the greater a person’s cognitive reserve is and the milder any age-related changes will be. It is already proven that cognitive reserve is influenced by physical exercise, nutrition, career, leisure habits, level of education, socio-economic status, and several other factors.
A team of scientists from HSE University (Russia) and Northumbria University (UK) decided to investigate the effect of bilingualism on older people’s brain functioning and how it relates to other aspects of cognitive reserve.
The researchers conducted an experiment with 63 adults aged 60 or above. The participants were healthy and had no history of psychiatric or neurodegenerative impairments. The participation requirements for the study included at least partial knowledge of a second language (‘bilingualism’ in this case referring to the ability to speak two languages, no matter how fluently). Before the experiment, all of the participants took a questionnaire that investigated their cognitive reserve (including questions about the participants’ marital status, level of education, profession, social relationships, sports activities, etc.) The participants also had to indicate how long they had known a second language, how often and where they used it, and how fluent they were in this language.
The participants were presented with a ‘flanker task’, which is traditionally used to measure inhibitory executive control. In the task, participants are shown a row of five arrows; the central ‘target’ arrow is the key stimulus. The arrows to either side of the central arrow (the ‘flankers’) can point in the same direction as the key stimulus (congruent), the opposite direction (incongruent), or they can be replaced by other objects (such as squares). The participants were asked to indicate the direction of the central target, and to do so as quickly as possible.
In an incongruent situation (when the target and side arrows point in different directions), it is usually more difficult for a person to concentrate and give the correct answer. However, bilingualism showed a facilitatory effect on the task. The longer people had studied a second language and the more fluent they were, the better they performed in the experiment. It is worth noting that the level of subjects’ language skills played a greater role than the length of time they had been learning a second language. The researchers explain this result by noting that bilingual speakers constantly face similar conflicts in daily life, in which they must make choices and switch between two linguistic systems.
Federico Gallo, Junior Research Fellow at the HSE University Institute of Cognitive Neuroscience
‘Unlike other factors that shape cognitive reserve, bilingualism is unique in that it is constantly present in our lives. We can take up and give up physical exercise, go on one diet or another, or change jobs, but language remains with us all the time. We communicate, watch movies, and read books, and the language centres are constantly working in our mind. We witnessed an interesting phenomenon in this experiment: with a high level of language proficiency, the correlation between successful conflict resolution and other components of cognitive reserve disappeared. This suggests that bilingualism’s benefits on cognitive reserve might be stronger than those of other known factors.’
Proficiency in two or more languages improves brain functioning not only in healthy people, but also in people with various neurodegenerative disorders (dementia, Alzheimer's, Parkinson's disease, stroke). In another article published in Frontiers in Human Neuroscience, Federico Gallo and his colleagues provide an overview of the latest research on bilingualism and aging. The data suggest that active bilinguals are diagnosed with neurodegenerative diseases 5–7 years later than monolingual speakers. Scientists believe that bilingualism improves not only the executive functioning of the brain, but also episodic, working and semantic memory, and even increases overall fluid intelligence.
‘There are no really effective drugs available today to prevent or slow down brain ageing. It takes enormous financial resources to develop pharmaceutical treatments. Therefore, finding and researching alternative, non-drug ways to slow down cognitive ageing should become a priority in science. In the long term, we plan to study how the benefits of bilingualism on ageing may vary with different language pairs,’ says Federico Gallo.
See also:
Microgravity Rewires Connectivity in Cosmonauts' Brains
After studying the brain scans of 13 Russian cosmonauts who participated in space missions to the ISS from 2014 to 2020, scientists discovered that prolonged exposure to microgravity had an impact on the connectivity of the brain structures responsible for adapting to unfamiliar conditions. The study revealed that these connections may not always return to their original state after the flight. The paper has been published in Communications Biology.
EEG and Eye Tracking Help Calculate Attentional Engagement Index
Researchers at the HSE Institute of Cognitive Neuroscience have discovered that analysing the electrical activity in the brains of a small group of people and studying their visual attention makes it possible to predict the impact of an online advertising campaign on a much larger group of 300,000 consumers. The paper has been published in Brain Sciences.
HSE Researchers Can Now Measure Individual Decision-making Time
HSE researchers have developed an algorithm for estimating individual response preparation period duration. Their approach can help diagnose disruptions in decision-making and motor functions associated with certain diseases. The study findings are published in PLoS ONE. The research was financed by a megagrant from the Russian government as part of the 'Science and Universities' National Project.
Neural Prosthesis Uses Brain Activity to Decode Speech
Researchers from HSE University and the Moscow State University of Medicine and Dentistry have developed a machine learning model that can predict the word about to be uttered by a subject based on their neural activity recorded with a small set of minimally invasive electrodes. The paper 'Speech decoding from a small set of spatially segregated minimally invasive intracranial EEG electrodes with a compact and interpretable neural network' has been published in the Journal of Neural Engineering. The research was financed by a grant from the Russian Government as part of the 'Science and Universities' National Project.
Corpus Callosum Found to Switch Off Right Hemisphere During Speech
A study by the HSE Centre for Language and Brain has confirmed the role of the corpus callosum in language lateralisation, ie the distribution of language processing functions between the brain's hemispheres. The authors came up with an innovative language task for their study subjects and applied advanced neuroimaging methods to the data collected. A paper on their findings has been published in PLoS ONE. The research was financed by a grant from the Russian government as part of the 'Science and Universities' National Project.
Ketamine Found to Increase Brain Noise
An international team of researchers including Sofya Kulikova, Senior Research Fellow at the HSE University-Perm, found that ketamine, being an NMDA receptor inhibitor, increases the brain's background noise, causing higher entropy of incoming sensory signals and disrupting their transmission between the thalamus and the cortex. This finding may contribute to a better understanding of the causes of psychosis in schizophrenia. An article with the study’s findings has been published in the European Journal of Neuroscience.
Speech Register Switching Causes Brain to Struggle with Comprehension
According to researchers at the HSE Centre for Language and Brain, processing a word which is markedly different in style from the rest of the sentence uses the same brain mechanisms as making sense of a semantically incongruent word. These mechanisms reflect the brain’s efforts to process an unexpected term. The study findings have been published in the Journal of Neurolinguistics. The research was financed by a grant from the Russian Government as part of the 'Science and Universities' National Project.
Only Left Hemisphere Involved in Action Naming
An international team including researchers from the HSE Centre for Language and Brain and the HSE Institute for Cognitive Neuroscience have demonstrated the critical role of the left, but not the right, inferior frontal gyrus in action naming. The study findings are published in Brain Structure and Function.
Machine Learning Predicts Epileptogenic Activity from High-Frequency Oscillation Rates
In an innovative study, researchers from HSE University, RAN Institute of Linguistics, and the National Medical and Surgical Centre named after N.I. Pirogov measured and analysed high-frequency oscillations (HFO) in different regions of the brain. An automated detector predicted seizure outcomes based on HFO rates with an accuracy rate of 85%, and by applying machine learning, made it possible to distinguish between epileptogenic and non-epileptogenic HFO. The study’s findings are published in Frontiers in Human Neurosciences.
HSE Researchers Caused People to Behave Less Rationally by Suppressing Activity in Specific Parts of the Brain
Researchers at the HSE Institute for Cognitive Neuroscience have shown experimentally that magnetic stimulation of the prefrontal cortex of the brain causes test subjects to act less rationally, changing how they assess possible outcomes at the moment they make risky decisions. The scientists believe that the discovery will provide a better understanding of the mechanisms that give rise to gaming addiction. The results of the study were published in the journal Scientific Reports.