Electrical Brain Stimulation Helps Memorise New Words
A team of researchers at HSE University, in collaboration with scientists from Russian and foreign universities, has investigated the impact of electrical brain stimulation on learning new words. The experiment shows that direct current stimulation of language centres—Broca's and Wernicke's areas—can improve and speed up the memorisation of new words. The findings have been published in Neurobiology of Learning and Memory.
The transcranial direct current stimulation (tDCS) technique involves applying a low direct current to specific areas of the brain. The advantages of tDCS include its simplicity, affordability, and non-invasive nature, meaning it does not require surgical intervention or expensive equipment. All that is required is the correct placement of electrodes on the head.
Researchers from HSE University, the N.P. Bekhtereva Institute of the Human Brain of the Russian Academy of Sciences, Sirius University, and the Gestalt Centre London, in collaboration with St Petersburg State University, investigated how transcranial direct current stimulation of Broca's and Wernicke's areas affects new word acquisition. These two areas are the brain's primary language centres, typically located in the left hemisphere for most people. The authors of the study conducted a large-scale, complex experiment involving 160 participants.
'We developed a rather complex experimental design, aiming to account for as many factors influencing learning as possible to obtain the most comprehensive picture of the process of acquiring new words. We aimed to determine whether transcranial direct current stimulation actually aids in memorising new words, whether a specific stimulation mode influences memorisation, and which brain area—Broca's or Wernicke's—plays a more significant role in the process of learning new words,' explains Olga Sherbakova, Leading Research Fellow at the Cognitive Health and Intelligence Centre of the HSE Institute for Cognitive Neuroscience.
To account for all these factors, participants were randomly assigned to five groups, subjected, respectively, to anodal stimulation of Broca’s area, anodal stimulation of Wernicke’s area, cathodal stimulation of Broca’s area, cathodal stimulation of Wernicke’s area, and placebo stimulation as a control, with inactive electrodes placed on the scalp.
The stimulation lasted 15 minutes, after which participants were instructed to memorise 16 new words—or more precisely, pseudowords—designed specifically for the experiment using the phonetic and rhythmic structure of the Russian language.
'People use two strategies to learn new words: explicit learning, where we are shown an object and told, "this is a table," and implicit learning, where we infer the meaning of a word from its context. In our experiment, we aimed to determine which memorisation strategy would be more effective under stimulation,' Shcherbakova explains. 'Additionally, we asked the participants to repeat some words aloud to investigate whether, as is commonly believed, articulation—pronouncing memorised words aloud—actually aids in memorisation.'
During the experiment, participants were shown images of unfamiliar objects, such as ancient musical instruments or rare deep-sea fish. While viewing each image, participants either heard a new word, such as 'This is SEN' (explicit strategy), or a question, such as 'Is SEN furry?' (implicit strategy).
After the learning phase, each group was assessed to determine which of them learned the new words most effectively and whether the learning strategy had any impact on the outcome. Participants first had to recognise a word by ear and then associate it with the image. The outcome assessment considered both the speed and accuracy of the response.
The results of the experiment show that both the explicit and implicit strategies lead to similarly successful word acquisition but engage different neural mechanisms, as evidenced by the varying effects of the different stimulation modes. It was also found that articulation contributes to better memorisation: participants recognised the words they had said aloud during the learning phase more accurately and quickly.
Most importantly, the study authors demonstrated that transcranial direct current stimulation significantly improves word memorisation, with the greatest effect resulting from anodal stimulation of Broca's area and cathodal stimulation of Wernicke's area. It is also important to note that the study found no adverse effects of tDCS on the outcomes of word learning in any of the groups.
This is the first tDCS study to consider such a wide range of factors potentially affecting language learning and to yield reliable results. 'We were able not only to demonstrate that tDCS has a positive effect on language learning, but also to identify the optimal stimulation modes for such learning,' Sherbakova emphasises.
In the future, the researchers plan to investigate the delayed effects of tDCS and determine how long its positive impact on the brain's language areas lasts. Potentially, transcranial direct current stimulation could be used to restore language abilities in patients after a stroke, brain injury, or neurodegenerative disease, as well as to enhance the cognitive abilities of healthy individuals.
See also:
HSE Scientists Reveal How Staying at Alma Mater Can Affect Early-Career Researchers
Many early-career scientists continue their academic careers at the same university where they studied, a practice known as academic inbreeding. A researcher at the HSE Institute of Education analysed the impact of academic inbreeding on publication activity in the natural sciences and mathematics. The study found that the impact is ambiguous and depends on various factors, including the university's geographical location, its financial resources, and the state of the regional academic employment market. A paper with the study findings has been published in Research Policy.
Group and Shuffle: Researchers at HSE University and AIRI Accelerate Neural Network Fine-Tuning
Researchers at HSE University and the AIRI Institute have proposed a method for quickly fine-tuning neural networks. Their approach involves processing data in groups and then optimally shuffling these groups to improve their interactions. The method outperforms alternatives in image generation and analysis, as well as in fine-tuning text models, all while requiring less memory and training time. The results have been presented at the NeurIPS 2024 Conference.
When Thoughts Become Movement: How Brain–Computer Interfaces Are Transforming Medicine and Daily Life
At the dawn of the 21st century, humans are increasingly becoming not just observers, but active participants in the technological revolution. Among the breakthroughs with the potential to change the lives of millions, brain–computer interfaces (BCIs)—systems that connect the brain to external devices—hold a special place. These technologies were the focal point of the spring International School ‘A New Generation of Neurointerfaces,’ which took place at HSE University.
New Clustering Method Simplifies Analysis of Large Data Sets
Researchers from HSE University and the Institute of Control Sciences of the Russian Academy of Sciences have proposed a new method of data analysis: tunnel clustering. It allows for the rapid identification of groups of similar objects and requires fewer computational resources than traditional methods. Depending on the data configuration, the algorithm can operate dozens of times faster than its counterparts. Thestudy was published in the journal Doklady Rossijskoj Akademii Nauk. Mathematika, Informatika, Processy Upravlenia.
Researchers from HSE University in Perm Teach AI to Analyse Figure Skating
Researchers from HSE University in Perm have developed NeuroSkate, a neural network that identifies the movements of skaters on video and determines the correctness of the elements performed. The algorithm has already demonstrated success with the basic elements, and further development of the model will improve its accuracy in identifying complex jumps.
Script Differences Hinder Language Switching in Bilinguals
Researchers at the HSE Centre for Language and Brain used eye-tracking to examine how bilinguals switch between languages in response to context shifts. Script differences were found to slow down this process. When letters appear unfamiliar—such as the Latin alphabet in a Russian-language text—the brain does not immediately switch to the other language, even when the person is aware they are in a bilingual setting. The article has been published in Bilingualism: Language and Cognition.
HSE Experts Highlight Factors Influencing EV Market Growth
According to estimates from HSE University, Moscow leads in the number of charging stations for electric vehicles in Russia, while Nizhny Novgorod ranks first in terms of charging station coverage, with 11.23 electric vehicles per charging station, compared to 14.41 in Moscow. The lack of charging infrastructure is one of the key factors limiting the growth of the electric vehicle market. This is stated in the study titled ‘Socio-Economic Aspects of Introducing Electric Vehicles in Commercial Transportation’ conducted by experts from the Institute of Transport Economics and Transport Policy Studies at HSE University.
Machine Learning Links Two New Genes to Ischemic Stroke
A team of scientists from HSE University and the Kurchatov Institute used machine learning methods to investigate genetic predisposition to stroke. Their analysis of the genomes of over 5,000 people identified 131 genes linked to the risk of ischemic stroke. For two of these genes, the association was found for the first time. The paper has been published in PeerJ Computer Science.
First Digital Adult Reading Test Available on RuStore
HSE University's Centre for Language and Brain has developed the first standardised tool for assessing Russian reading skills in adults—the LexiMetr-A test. The test is now available digitally on the RuStore platform. This application allows for a quick and effective diagnosis of reading disorders, including dyslexia, in people aged 18 and older.
Low-Carbon Exports Reduce CO2 Emissions
Researchers at the HSE Faculty of Economic Sciences and the Federal Research Centre of Coal and Coal Chemistry have found that exporting low-carbon goods contributes to a better environment in Russian regions and helps them reduce greenhouse gas emissions. The study results have been published in R-Economy.