Scientific results:
The Center for Language and Brain conducts research in the domain of psycho- and neurolinguistics aimed, from the basic research viewpoint, at the determination of cognitive neural foundations of language, and, in terms of practical applications, at the prevention and diagnostics of speech disorders.
- The first series of studies was focused on post-operative language mapping in neurosurgical patients. We have developed and validated a paradigm of functional magnetic resonance imaging involving a sentence completion task. All in all, pre-operative mapping has been performed in a group of 65 patients (25 patients with brain tumors and 40 patients with pharmacoresistant epilepsy). Individual language activation maps were compared with the localization of language zones determined during intra-operative mapping with the use of direct electrical stimulation. Significant individual variability was found in the coherence of mapping based on functional magnetic resonance imaging and direct electrical stimulation. Also within the domain of pre-operative mapping we have conducted reconstructions of individual anatomy of white matter pathways of the brain related to speech and intra-operatively checked their functions by direct electrical stimulation in the same group of neurosurgical patients. The Laboratory has also, for the first time in Russia, developed a standardized protocol for the pre-operative mapping in patients with pharmacoresistant epilepsy and tumors with the use of transcranial magnetic stimulation (TMS). In this protocol we used thoroughly selected language stimuli and tested the critical parameters of TMS in a group of healthy volunteers: the frequency of stimulation, the orientation of the coil and the delay of stimulation in relation to the presentation of the stimulus.
- The second direction is oriented towards the development of diagnostic tests for adult patients with aphasia. Materials of the ScreeLing test have been adapted from the Dutch language to Russian. Its standardization was performed in a control group (N=120) as well as in a group of patients who had suffered a stroke (N=120). We calculated the indicators of validity and reliability of the test. We also performed a clinical testing of the «Aphasia: express verification» test — one more screening tool to detect speech disorders in the acute post-stroke period. We have published the Russian Aphasia Test (RAT) developed by the Center. Unlike all the existing Russian-language tools, RAT is designed for the comprehensive assessment of the state of comprehensive, synthesis and reproduction of language at each of the main language levels (phonological, lexico-semantic, syntactic and discursive). The test was computerized and is available in the form of an application for tablet computers, which ensures its uniform procedure. One more diagnostic tool for the assessment of language skills in children, «Clinical assessment of main language competences» was standardized and validated for typically developing Russian monolinguals, Russian-English bilingual children and children with delayed language development in the context of autism. At the same time, the accumulated data allowed to build a perception of the rate of typical development of Russian language skills and deviations from the norm in a bilingual and a clinical population. As for diagnostic tools for the assessment of reading in children, we have developed a battery of tests for the assessment of reading of words and pseudowords with two parallel variants. This first standardized battery of tests of Russian-language reading, the materials of which were prepared in view of relevant linguistic and psycholinguistic parameters. Moreover, we have developed and standardized a test for the assessment of a non-language cognitive function — memory — by adapting the Rey Auditory Verbal Learning Test (RAVLT) for adults speaking Russian. To assess the executive functions, we computerized the color trail test that includes, apart from Russian, 18 languages (English, Arabic, Greek, Danish, Spanish, Chinese, Italian, Catalan, Korean, German, Dutch, Polish, Portuguese, Turkish, Swedish, Ukrainian, French, Japanese). For both cognitive tests we collectednormative data.
- To understand the patterns of language disorders in various clinical populations, we have conducted and analyzed a comprehensive assessment of speech in patients who underwent neurosurgeies to remove brain tumor and patients who suffered a stroke. The produced results indicate the discrepancy between non-specific language disorders after surgical removal of tumors and traditionally observed syndromes of post-stroke aphasia. We have also discovered that in patients with minor speech impediments, lesions are located predominantly in the left temporal pole, a region that is seldom damaged by a stroke due to the peculiarities of the anatomy of vessels. Thus, the behavioral features of speech disorders in neurosurgical patients turned out to be directly correlated with the specifics of the neuroanatomic distribution of their lesions in comparison with the post-stroke population. In another research we have analyzed the patterns of speech disorders in the field of the perception and generation of verbs in patients with post-stroke aphasia. The results from 54 patients indicated that the participants with aphasia were grouped on the basis of the general severity of speech disorders, while the models of disorders of the processing of verbs and sentences had strong individual variability and were not related to the types of aphasia. Another longitudinal research has been performed among persons with aphasia in the chronic post-stroke period. Their profile of language assessment structural neuroimaging were obtained before an intensive rehabilitation course. We have determined the relation between the preservation of white brain matter in the left hemisphere of the brain and distinct indicators of spontaneous speech, while the indicators of the white matter of the right hemisphere of the brain predict the cumulative efficiency of therapy. One more study was devoted to the mechanics of reading in persons with hearing disorders: adults and children. The analysis of trajectories of eye movement (scanpaths) during reading indicated that early access to sign language influences reading fluency in adults with hearing disorders: patients that had early access to sign language more frequently demonstrate more fluent reading. To the contrary, early access to spoken language did not influence reading fluency. An experiment involving children has demonstrated that reading speed and the level of nonverbal intellect in children with hearing disorders are comparable with the norm, while for some indicators of reading the deaf are superior to typically developed children. For instance, in deaf children the position of the first fixation on a word was closer to the center of the word, also they showed less fixations on longer words. In a similar research of reading, trajectories of eye movements in children with normal hearing with dyslexia and without it were compared. It was demonstrated that in both groups reading skills improved with age, but in typically developed children progress was faster. It turned out that as soon as in the second grade they were at the penultimate stage of development, and in the forth grade they were reading like adults. Children with dyslexia demonstrated the same trajectory of development as those with a three-year delay.
We have also studied the mechanism of speech processing in persons without brain damage and without speech disorders. We researched the predictability of words and their morphological features during reading, as well as compared the indicators of predictability collected via a questionnaire filled by the participants and from a language model trained over a large array of texts. Using the analysis of eye movements, we have found that the higher the possibility of predicting a grammatical feature of a word, the faster people read the word. Supposedly, for languages with complex morphological systems predicting is, to a large extent, related to forecasting grammatical features. The possibilities of encountering grammatical features collected from the language model explained the time of reading of words similarly to the posbbilities obtained from the questionnaire, which means that the indicators of predictability can be efficiently extracted from the corpus. In the second research we checked the influence of age on the mechanisms of morphological processing. It has been determined that regardless of age, the mechanisms corresponded to the dual pathway model, according to which the processes of morphological decomposition and full-word access to the word form occur in parallel during the processing of polymorphic words. In another study we compared the mechanisms of sentence processing in younger and older people. In contrast with our predictions, the results demonstrated that the superficial processing of speech emerges as soon as adolescence begins and intensifies in the older age. Then we reviewed the existing behavioral and eye-movement data that reflect the quality of lexical representation in foreign and native language processing. On the basis of the review we formulated a hypothesis on fuzzy lexical representations, according to which the vocal form of a word, its meaning and the correspondence between the form and the meaning are approximate in a non-native language even at the advanced level of language proficiency. This is related to the later acquisition of a foreign language, it has consequences for fast access to the mental lexicon and explains the frequent lexical substitutions in the non-native language, the weak lexical competition, the reliance on sublexical processes during the recognition of foreign words, the prevalence of the word form over the meaning, the pronounced role of episodic memory in memorizing foreign words. We have also studied the patterns of eye movement during reading in Russian-speaking monolinguals. A cluster analysis of eye movements uncovered three main reading patterns that to equal extent characterized all four tested cohorts of participants: monolingual Russian-speaking adults, Russian-speaking children, Americans studying Russian as a foreign language and native Russian speakers living in the USA. Thus, the reading pattern was influenced by other factors as well: for instance, in native speakers of an «inherited» language we found a relation between the rate of reading aloud and the pattern of reading to oneself, while in persons studying Russian as a foreign language it is related to verbal fluency. The trend was determined by the level of Russian language fluency.
Implemented results of research:
On of the directions of the work of the Center is the development of standardized tests that allow to assess the degree and nature of both speech and written language and the introduction of those tests into logopedic and clinical practice:
Education and career development:
The educational activities of the Center is conducted for the dissemination of the achieved results among the aspiring generation of researchers at the Higher School of Economics. We have developed and implemented the following education programs: the experimental track for the bachelor’s degree program «Experimental and computer linguistics» of the Faculty of Humanities; the course «Psychology and neurophysiology of language and speech» – for the bachelor’s degree program «Psychology» of the Faculty of Social Sciences; the periodic courses: «Experimental linguistics», «Experimental methods in psycho- and neurolinguistics», «Dyslexia and dysgraphia: a neurolinguistic approach» – for the bachelor’s and master’s degree program the School of Linguistics of the Faculty of Humanities.
Additionally, employees of the Center provide the scientific supervision of term papers, Final qualifying works, summer internships and Candidate of Sciences dissertations at the Faculty of Humanities, the Faculty of Social Sciences, the Faculty of Computer Science, the Moscow Institute of Electronics and Mathematics.
In 2019, we organized and staged international summer and winter school as well as two international conferences. A periodic open research seminar was conducted that featured 37 presentations.
In 2020, we have conducted two schools: the summer school «Language acquisition by children» and the winter school «Analysis of eye movements during reading» as well as a series of а educational seminars on academic writing.
Employees of the Center, including the leading scientist Roelien Bastiaanse, delivered five education courses for students of the Higher School of Economics, one of the courses had been developed in 2020 and was delivered for the first time.
In 2021, we organized 5 major scientific and educational events that were open not only to students of the Higher School of Economics but also for interested students of other universities, teachers, research fellows, clinical professionals from any institutions of Russia and other countries:
- A traditional summer school of neurolinguistics annually organized by the Center was conducted fully online and was devoted to the topic «Science of reading: from the brain to behavior and back». Thanks to the online format, the school attracted 304 participants from all around the world.
- Four offline educational events have been organized to develop practical skills in students and young researchers: the series of educational seminars «Academic writing for psycho- and neurolinguists», a master class in eye tracking, a course in the analysis of diffusion-weighted MRI data, the series of master classes «Applications of transcranial magnetic stimulation for language mapping in the brain».
The Center frequently organizes the research seminar «Neurolinguistics Thursday».
In 2022, employees of the Center organized the Ninth Summer Neurolinguistics School in the online format (27-28 June 2022). The school was devoted to the topic «Experimental research of languages of peoples of Russia». This topic continues the topic of experimental linguistics in little-studied languages of Russia. Among the invited speakers were: Andrian Vlakhov (Arctic Social Sciences and Humanities Laboratory of the Higher School of Economics), Timofey Mukhin and Polina Nasledskova (International Linguistic Convergence Laboratory of the Higher School of Economics), Yuliya Normanskaya (Institute of Linguistics of the Russian Academy of Sciences and the Ivannikov Institute for System Programming of the Russian Academy of Sciences), Michael Daniel (International Linguistic Convergence Laboratory of the Higher School of Economics), Marina Usacheva (Institute of Linguistics of the Russian Academy of Sciences). Moreover, short presentations were delivered by participants selected on the basis of a review of submitted abstracts. Thanks to the online format, the school reached a wide audience: 350 students from various countries registered for the school. The program of the School and extensive information are available at the website https://www.hse.ru/neuroling/summer_school_2022.
Three Candidate of Sciences and one Doctor of Sciences dissertations have been prepared and defended.
Other results:
- The Laboratory has provided neurolinguistic support in 50 neurosurgical operations.
- Under the supervision of employees of the Center every year students of the Higher School of Economics complete dozens of course works and graduate qualification works. Many of them additionally participate in other projects of the Center to broaden their experimental skills and generate more experience in empirical research. Students of other universities (the Moscow State University, the Novosibirsk State University) also submit applications to volunteer for the Center.
- Several high-resolution video-oculographs are used to accurately measure the mechanisms of reading in adults and children, healthy and diseased. Two electroencephalography systems (one of them portable) allow to study the neurophysiology of language. A transcranial magnetic stimulator and a transcranial micropolarizer allow for therapeutic research and language mapping in the brain. Having such a modern battery of neurobiology tools makes our research advanced and precise.
Collaborations:
- Center for Speech Pathology and Neurorehabilitation of the Department of Health of City of Moscow, Pirogov National Medical and Surgical Center of the Ministry of Health of Russia, Neurological clinic «Epilepsy Center», Federal State Budgetary Research Institution «Neurology Research Center», «Treatment and Rehabilitation Center» of the Ministry of Health of Russia, Multi-profile Psychology Center «Territory of Happiness», Memory clinic (branch of the Moscow Psychiatric Hospital No. 1 named after N. A. Alekseyev), Private additional training institution «Institute of age-specific neuropsychology» (Russia): joint research.
- School No. 1236, School No. 548 «Tsaritsino» (kindergarten), Combined-type Kindergarten No. 56», School No. 1541 (Russia): testing of applied developments.
This collaboration resulted in the creation of clinical tools for the prevention (intra-surgical mapping of speech), diagnostics (testing for the assessment of speech function) and correction of speech disorders (development of speech functions restoration).
- Kindergarten No. 782 of the City of Moscow, Institute of Humanities and Ecology (Russia): data acquisition for the research of child speech.
- Republican Clinical Hospital of the Ministry of Health of the of Chuvash Republic (Russia): joint research and implementation of the results into clinical practice, participation in discussion of the demand of the clinical for diagnostic tests.
- Kazan (Volga region) Federal University (Russia): joint research, adaptation of diagnostic tests for bilingual patients.
- Erasmus Mundus Master’s degree program in clinical linguistics (Germany, the Netherlands, Finland): student exchanges.
