Summary: We delivered theta-burst stimulation to primary motor cortex directly before a novel verb learning task. Our results show that TMS of M1 (but not active or sham controls) interferes with the learning process, as indexed by measures of movement kinematics and a higher number of errors during training. Overall, our study demonstrates the M1’s causal involvement in the earliest phases of word learning and rapid encoding of semantic motor information.
a neuroscientist at UC San Francisco. I research how our brain, the most complex object in the universe, does what appears to us the simplest and most natural of things: human language.
I've always been fascinated by the richness and complexity of our meaning-making consciousness. How is it that the brain lets us turn arbitrary bursts of sound, or inarticulate symbols on a piece of paper, into means of conjuring and transmitting an infinite array of thoughts and impressions? As a scientist, I apply my creativity and problem-solving skills to uncover the mechanistic basis of these processes.
I am a neuroscientist who studies how the brain lets us acquire, use, and communicate meaning through the medium of language. I was born and raised in Montenegro, but have since lived and worked in numerous countries. I hold a PhD and MPhil in Cognitive Neuroscience from the University of Cambridge. Right now, I work as a postdoctoral researcher at the Laboratory for Educational Neuroscience at UC San Francisco.
Professionally, I believe scientists should not be afraid to blur the edges of their discipline: learning about ideas from other fields of knowledge can only enrich our work and understanding. I tend to practice such intellectual and methodological pluralism daily, and nowhere is it as beneficial as in the study of language. After all, language influences every human activity and sphere of life, and my own and others' scientific findings show that language processing engages every sensory, motor, emotional, and associative system in the brain. The interplay and relative contribution of these modalities to learning and comprehension of words are the topic of my current research, which I conduct primarily using fMRI, MEG, and TMS methods.
I passionately believe in the importance of public engagement, and communicate my science both through international peer-reviewed journals, as well as varied outreach activities.
My primary scientific focus lies with the neurobiological mechanisms underlying semantic processing and word learning. In particular, I am interested in: A. interactions between linguistic areas and other modality-specific neural systems, B. the microstructural and functional signatures of language learning and comprehension, and C. the decay of these representations due to ageing or disease.
Since 2018: Postdoctoral Researcher, brainLENS - Laboratory for Educational NeuroScience, University of California San Francisco, USA.
Tasks: Studying how the brain changes over time in children learning two (or more) languages (from kindergarten to 3rd grade). The goal of this project is to test and evaluate models of literacy acquisition, as well as discover the impact that learning multiple languages may have on cognition, socio-emotional skills and creativity.
2015 - 2018 Postdoctoral Researcher, Centre of Functionally Integrative Neuroscience (CFIN), Aarhus University, Denmark.
Tasks: Researching the neurobiological mechanisms underlying lexical and semantic processing. Most recently, employed combined TMS, fMRI, DKI, and behavioural methods to identify the spatial profile and causal role of early microstructural brain signatures of word learning.
2011 - 2015: PhD in Cognitive Neuroscience, Department of Theoretical and Applied Linguistics (DTAL), University of Cambridge, United Kingdom.
Tasks: Researched the involvement and role of functionally differentiated brain areas in processing language. Over a range of experiments, I looked at how the automatic activation of sensory-motor representations during semantic access sheds light on the way monolinguals and bilinguals structure their lexicon. This work highlighted the crucial role of individual differences, experience, and contextual factors in comprehension.
2012 - 2014: Visiting Doctoral Researcher, MRC Cognition and Brain Sciences Unit (CBU), University of Cambridge, United Kingdom.
Tasks: Conducted high-density EEG recordings of bilingual speakers. Investigated oscillatory brain activity during word procesing, particularly as it relates to motor cortex involvement in representing semantic knowledge. Additionally received in-depth training in fMRI and MEG, as well as advanced signal processing techniques such as ICA.
2010 - 2011: MPhil Linguistics, Department of Theoretical and Applied Linguistics (DTAL), University of Cambridge, United Kingdom.
I tackle research projects with an analytic and systematic rigour, generating novel ideas, as well as looking for logical solutions informed by past experience and research literature. I am confident enough to challenge established practices and come up with new ways of working.
Managing research and teaching workload by setting priorities, planning, and monitoring progress. Successfully organised numerous well-attended social events, talks, and conferences.
Experienced with statistical and research software such as SPSS, R, MATLAB, SPM, Fieldtrip Superlab, E-Prime, BrainVision Analyzer, and EEGlab.
Able to write for a variety of audiences, both in scientific publications as well as more general media. Received excellent end of term feedback from students on my teaching. Developed confidence in public speaking through presenting at numerous conferences, meetings, and on TV.
I have excellent skill in creating scientific graphics and communication using Adobe Illustrator, Photoshop, and InDesign.
I am a native speaker of Serbo-Croatian, and have full professional proficiency in English (IELTS score: 9.0) and German (CEFR score: C2). Apart from these, I have intermediate knowledge of Russian (primary and secondary school).
Teacher at Interdisciplinary Summer School on Neuroimaging (ISSN), Aarhus, Denmark
Tasks:Taught a course on Magneto- and Electroencephalography, and transcranial magnetic stimulation (TMS), to a group of 34 bachelor and master students from Denmark, the UK, Austria, Germany, Australia, and Belgium.
Doctoral Training Centre Fellow at Cambridge Language Sciences Initiative
Tasks: Ran two networking sesions for early career researchers at the University of Cambridge. Organised a series of ESRC funded interdisciplinary workshops, aimedat helping solve common issues encountered by students at all stages of experimental research.
Society Secretary at Cambridge University Linguistic Society
Tasks: Organizing the Society’s academic and social events, including 10 annual guest lectures; liaising with the speakers and the various colleges involved; maintaining relations and cooperation with University internal and external research partners and sponsors.
Supervisor at University of Cambridge, Linguistics Tripos
Supervisor at the Department of Theoretical & Applied Linguistics, Li16-Psychology of language processing and learning course. Colleges: King's, Fitzwiliam, Christ's, and Gonvile & Caius.
Language Teacher at EF Education First, Cambridge
Tasks: Teaching using the Efekta Language blended learning system, as well as planning lessons and development seminars and workshops.
SUBMITTED OR UNDER REVIEW
Shpektor A., Vukovic, N. & Feurra, M. The BDNF val66met polymorphism affects the Level of Processing effect of memory: A deep and shallow rTMS study. (under review).
Vukovic N., Shtyrov, Y. Learning with the wave of the hand: Kinematic and TMS evidence of primary motor cortex role in category-specific encoding of word meaning. NeuroImage (2019)
Vukovic, N., Fardo, F. & Shtyrov, Y. When words burn – language processing differentially modulates pain perception in typical and chronic pain populations. Language and Cognition (2019)
Vukovic, N. & Shtyrov, Y. Cortical networks for reference-frame processing are shared by language and spatial navigation systems. NeuroImage (2017)
Vukovic, N., Feurra, M., Shpektor, A., Myachykov, A. & Shtyrov, Y. Primary motor cortex functionally contributes to language comprehension: An online rTMS study. Neuropsychologia 96, 222-229 (2017).
Vukovic, N. & Williams, J. N. Individual differences in spatial cognition influence mental simulation of language. Cognition 142, 110–122 (2015).
Vukovic, N. & Shtyrov, Y. Cortical motor systems are involved in second-language comprehension: evidence from rapid mu-rhythm desynchronisation. Neuroimage 102, 695–703 (2014).
Vukovic, N. & Williams, J. N. Automatic perceptual simulation of first language meanings during second language sentence processing in bilinguals. Acta Psychologica. 145, 98–103 (2014).
Vukovic, N. When Words Get Physical: Evidence for proficiency-modulated somatotopic motor interference during second language comprehension. Proceedings of 35th Annual Conference of the Cognitive Science Society. (2013).
Vukovic, N. Sensorimotor processing of action verbs in second language speakers. 5th Annual Embodied and Situated Language Procesing Conference, (2012).
Because the world inside our head can be even more complex and fascinating than the one outside, and its currency is language. It defines us and is the foundation of culture, education, and economic development. Unsurprisingly, impairments of language can be devastating for the affected individuals and their families, and costly for society. Studying its neural basis is thus beneficial at many levels.
We are not particularly strong, fast, or agile animals - what sets us apart is our reasoning & language. Learning about these unique human traits is intrinsically satisfying.
Language deficits are a debilitating consequence of many clinical conditions. A mechanistic understanding of language is a prerequisite for successful therapy.
Science can tell us how language is acquired & processed, how best to teach it in schools, or model using computers or AI - areas often based on anecdotal evidence.
I have extensive hands-on experience in conducting research using these methods.
My neuroscientific research programme addresses these broad topics and questions.
Where in the brain is the linguistic system? Early work with patients identified key structures in the frontal and temporo-parietal lobes: the so-called Broca's and Wernicke's areas. Since, we have discovered that many other areas contribute to language processing, including some "unlikely candidates", which were previously treated as separate domains. However, given this complex network, a significant challenge we have to solve is to characterise precise functions and contributions of different structures, and the neural mechanisms by which language is represented and processed.
How is it possible that reading or speaking lets us communicate and share thoughts with others? Importantly, words are not just sounds or symbols on paper - they are tools and triggers which lead the brain to behave in a certain way. Central to my research on comprehension is the idea that the brain simulates word meaning by reactivating perceptual, motor, and emotional states which mimick those we had when we first acquired (or subsequently used) the word. I study the neural dynamics of this semantic system using fMRI and MEG scanners, TMS stimulation, as well as computer-based tests.
What consequences does speaking multiple languages have on cognition? How are these learned and stored, and how do we contextually switch between them? While most current research suggests that the brain represents languages in a shared network, bilinguals also seem to draw upon additional resources, which require more study. In an increasingly globalised and technological world, understanding multilingualism has become very important, as is the question of how we can use neuroscientific principles to better teach language to our children, and even our computers.
Below are some of my recent publications, presentations, and data. These are provided to ensure timely and unbiased dissemination of academic work. Copyright resides with the respective copyright holders, as stated in each publication.
Published 2019 in NeuroImage
Published 2019 in Language and Cognition
Published 2017 in Neuropsychologia
Published 2017 in NeuroImage
Currently in review
Published 2015 in Cognition
Published 2014 in NeuroImage
Published 2014 in Acta Psychologica
A scientist’s duty is not only to produce rigorous and high-quality research, but also to take an active part in disseminating it, encourage debate and educate the public, thus maximising the transparency and impact of academic work in the community.
Q&A with a K-5 Classroom about brain science.
Week-long online science communication campaign.
"Brain Matters!" 2016 outreach event in Aarhus.
Interdisciplinary Summer School on Neuroimaging.
Science Talk on national TV in Montenegro.
CU Language Sciences Initiative workshops.
Cambridge "PhD Clinic" graduate workshops.
Talk at the Montenegrin Open Science Days 2014.
Podcast interview on "Growing up Bilingual".
Cambridge Uni Linguistic Society lecture series.
If you are a fellow researcher, journalist, or simply an interested individual, I’d love to hear from you.
brainLENS: Laboratory for Educational NeuroScience, UC San Francisco
Langley Porter Psychiatric Institute, 401 Parnassus Ave, Room A316, San Francisco, CA 94143
Vukovic, N., Shtyrov, Y.
Language processing recruits a core fronto-temporal cortical network, which is complemented by a distributed network of modality-specific areas (such as the motor cortex) to encode referential aspects of meaning. Since most studies typically focus on already fully-formed adult vocabulary, it remains unclear how and when exactly modality-specific areas become involved in language processing. Here, we addressed this question using a 3D virtual environment game to teach adult participants new action verbs and object nouns. To test the role of primary motor cortex (M1) in selectively encoding aspects of action verb meaning early on in the process of word learning, we delivered theta-burst stimulation to three groups of participants prior to learning: M1 TMS, active control TMS, and sham TMS. Our results show that TMS of M1 (but not active or sham controls) interferes with the learning process, as indexed by measures of movement kinematics and a higher number of errors during training. Thus, TMS disruption of M1 degrades learning outcomes when motor information is an integral part of lexico-semantic encoding. This effect was corroborated in a subsequent lexical decision task, which showed significant group- and word-category RT differences, suggesting category-specific effects of TMS on word learning. Overall, our study demonstrates the M1’s causal involvement in the earliest phases of word learning and rapid encoding of semantic motor information.
Language and Cognition (2019)
Vukovic, N., Fardo, F., Shtyrov, Y.
How do we communicate our pain to others? The challenge of conveying such a highly individual experience in words is faced daily by many sufferers of chronic pain and their doctors. Moreover, such linguistic strategies are especially relevant in situations where no obvious reference to physical injuries or tissue damage can be made. Neurolinguistically, this question is directly linked to understanding the brain mechanisms behind the encoding, storage, and comprehension of word meanings. An influential view posits that comprehension involves mentally simulating sensorimotor experiences which words refer to. Here, we test the hypothesis that both pain word comprehension and first-hand experiences of pain rely on a common neural substrate, leading to a prediction that word processing should modulate the perception of noxious stimuli. We used a priming task and asked neurotypical and chronic pain participants to read sentences containing literal or metaphoric pain descriptors, and then rate the intensity of thermal pain stimuli. We found that pain language comprehension modulated participants’ ratings of pain intensity. Furthermore, this effect depended on linguistic context as well as individual pain history. We discuss our findings within the larger theoretical debate on the nature of semantic representations, and point to their potential relevance for clinical practice.
Vukovic, N., Feurra, M., Shpektor, A., Myachykov, A., Shtyrov, Y.
Among various questions pertinent to grounding human cognitive functions in a neurobiological substrate, the association between language and motor brain structures is a particularly debated one in neuroscience and psychology. While many studies support a broadly distributed model of language and semantics grounded, among other things, in the general modality-specific systems, theories disagree as to whether motor and sensory cortex activity observed during language processing is functional or epiphenomenal. Here, we assessed the role of motor areas in linguistic processing by investigating the responses of 28 healthy volunteers to different word types in semantic and lexical decision tasks, following repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex. We found that early rTMS (delivered within 200 ms of word onset) produces a left-lateralised and meaning-specific change in reaction speed, slowing down behavioural responses to action-related words, and facilitating abstract words – an effect present only during semantic, but not lexical, decision. We interpret these data in light of action-perception theory of language, bolstering the claim that motor cortical areas play a functional role in language comprehension.
Currently In Review
Shpektor, A., Vukovic, N., Feurra, M.
The Val66Met polymorphism of the Brain-Derived Neurotrophic Factor (BDNF) gene is known to alter brain structure and plasticity mechanisms. Although at the behavioral level Met carriers show differences in memory performance, little is known about the underlying neural mechanisms. Since previous studies with neuro-typical populations showed the critical role of the dorsolateral prefrontal cortex (DLPFC) in episodic memory processes, here we used repetitive Transcranial Magnetic Stimulation (rTMS) to causally address the role of left and right DLPFC in episodic retrieval in relation to the BDNF Val66Met polymorphism. To achieve this goal, we adopted a classical deep and shallow memory task. Participants encoded visually presented words while performing a semantic (living/non-living) or perceptual (letter judgment) task, followed by an incidental recognition memory task. Whereas encoding was free of stimulation, 10 Hz rTMS was delivered at retrieval over the left and right DLPFC. Vertex (active site) and no rTMS were included as control conditions. We found a significant drop of memory performance for the ValVal group during left DLPFC stimulation: the effect was specific for recognition of deeply encoded items. Conversely, rTMS had no impact on Met-carriers' memory performance. Our results represent the first causal evidence of rTMS modulatory effects during a cognitive task in relation to the Val66Met polymorphism. These findings highlight possible differences across the cortical memory network and plasticity mechanisms between the two BDNF genotypes, and might represent a step towards the development of genetically-based brain stimulation therapies in patients with memory impairments.
To help us live in the three-dimensional world, our brain integrates incoming spatial information into reference frames, which are based either on our own body (egocentric) or independent from it (allocentric). Such frames, however, may be crucial not only when interacting with the visual world, but also in language comprehension, since even the simplest utterance can be understood from different perspectives. While significant progress has been made in elucidating how linguistic factors, such as pronouns, influence reference frame adoption, the neural underpinnings of this ability are largely unknown. Building on the neural reuse framework, this study tested the hypothesis that reference frame processing in language comprehension involves mechanisms used in navigation and spatial cognition. We recorded EEG activity in 28 healthy volunteers to identify spatiotemporal dynamics in (1) spatial navigation, and (2) a language comprehension task (sentence-picture matching). By decomposing the EEG signal into a set of maximally independent activity patterns, we localised and identified a subset of components which best characterised perspective-taking in both domains. Remarkably, we find individual co-variability across these tasks: people's strategies in spatial navigation are also reflected in their construction of sentential perspective. Furthermore, a distributed network of cortical generators of such strategy-dependent activity responded not only in navigation, but in sentence comprehension. Thus we report, for the first time, evidence for shared brain mechanisms across these two domains - advancing our understanding of language's interaction with other cognitive systems, and the individual differences shaping comprehension.
Vukovic, N., Williams, J. N.
The factors that contribute to perceptual simulation during sentence comprehension remain underexplored. Extant research on perspective taking in language has largely focused on linguistic constraints, such as the role of pronouns in guiding perspective adoption. In the present study, we identify preferential usage of egocentric and allocentric reference frames in individuals, and test the two groups on a standard sentence-picture verification task. Across three experiments, we show that individual biases in spatial reference frame adoption observed in non-linguistic tasks influence visual simulation of perspective in language. Our findings suggest that typically reported grand-averaged effects may obscure important between-subject differences, and support proposals arguing for representational pluralism, where perceptual information is integrated dynamically and in a way that is sensitive to contextual and especially individual constraints.
Understanding neurocognitive mechanisms supporting the use of multiple languages is a key question in language science. Recent neuroimaging studies in monolinguals indicated that core language areas in human neo-cortex together with sensorimotor structures form a highly interactive system underpinning native language comprehension. While the experience of a native speaker promotes the establishment of strong action–perception links in the comprehension network, this may not necessarily be the case for L2 where, as it has been argued, the most a typical L2 speaker may get is a link between an L2 wordform and its L1 translation equivalent. Therefore, we investigated, whether the motor cortex of bilingual subjects shows differential involvement in processing action semantics of native and non-native words. We used high-density EEG to dynamically measure changes in the cortical motor system's activity, indexed by event-related desynchronisation (ERD) of the mu-rhythm, in response to passively reading L1 (German) and L2 (English) action words. Analysis of motor-related EEG oscillations at the sensor level revealed an early (starting ~150 ms) and left-lateralised coupling between action and semantics during both L1 and L2 processing. Crucially, source-level activation in the motor areas showed that mu-rhythm ERD, while present for both languages, is significantly stronger for L1 words. This is the first neurophysiological evidence of rapid motor-cortex involvement during L2 action–semantic processing. Our results both strengthen embodied cognition evidence obtained previously in monolinguals and, at the same time, reveal important quantitative differences between L1 and L2 sensorimotor brain activity in language comprehension.
Acta Psychologica (2014)
Research supports the claim that, when understanding language, people perform mental simulation using those parts of the brain which support sensation, action, and emotion. A major criticism of the findings quoted as evidence for embodied simulation, however, is that they could be a result of conscious image generation strategies. Here we exploit the well-known fact that bilinguals routinely and automatically activate both their languages during comprehension to test whether this automatic process is, in turn, modulated by embodied simulatory processes. Dutch participants heard English sentences containing interlingual homophones and implying specific distance relations, and had to subsequently respond to pictures of objects matching or mismatching this implied distance. Participants were significantly slower to reject critical items when their perceptual features matched said distance relationship. These results suggest that bilinguals not only activate task-irrelevant meanings of interlingual homophones, but also automatically simulate these meanings in a detailed perceptual fashion. Our study supports the claim that embodied simulation is not due to participants' conscious strategies, but is an automatic component of meaning construction.
In November 2018, I collaborated with Skype A Scientist, an organisation with matches scientists with classrooms around the world, especially in underserved and low-SES communities! We organised a 60 minute Q and A session with a K-5 classroom about brain science and what it’s like to work in STEM.
In November 2017, I led a community science outreach event in collaboration with SciComm Hub and Crastina. The week-long project popularised brain research and offered advice on using new media for science communication (video, podcasts, and Twitter). As a result, we were able to reach and interact with almost 12000 researchers and members of the public.
In June 2015, I had the pleasure of giving an interview with Channel 1 of the Montenegrin national television broadcaster. The conversation was a unique opportunity to present my work to a national audience, and explain the basics of neuroscience more broadly, and neurolinguistics, specifically - topics rarely discussed on mainstream television.
As the committee head of Cambridge University Linguistic Society from 2012 to 2014, I have helped organise the Society's academic and social events, where members can meet each other, discuss ideas, and network with professionals in the discipline. These events included 20 guest lectures, with internationally renowned speakers from universities across Europe and the US.
In this audio piece myself and other researchers, teachers, parents, and language specialists from around Cambridge and London, talk about the neuro-cognition of language, and about growing up bilingual.
I got invited to deliver an informal talk about the brain and language at the Montenegrin Open Science Days. The Festival, which is one of the main science promotion events in the country, focused on the neurosciences, in line with 2014 being declared the European Year of Brain Studies. The series of talks included presentations by international guests from the fields of Neurophisiology, Neuroinformatics, Cognitive Neuroscience, Functional and Structural Representations of the Nervous System and Human-Machine Inteface Design and Development.
In 2014 and 2015, I founded "The PhD Clinic" - a series of informal career-development workshops aimed at Cambridge graduate students in the language, cognitive and social sciences. With generous help and funding from the Cambridge Language Sciences Initiative and the ESRC, we ran 4 well-attended workshops on academic writing, publishing, and employability in academia and industry.
In 2014 I helped organise and run two networking sessions for early career researchers at the University of Cambridge. Supported by the Cambridge Language Sciences Initiative, these events brought together researchers from the different Faculties, Departments and Institutes at the University of Cambridge - as well as the general public - to build collaborations and discuss advances in the language sciences.
In July 2015, I taught a course on Magneto- and Electroencephalography, and transcranial magnetic stimulation (TMS), at the Interdisciplinary Summer School on Neuroimaging in Aarhus. The School was aimed at introducing talented and enthusiastic university students to basic aspects of preclinical and clinical brain imaging. We also discussed PET and fMRI, in light of their great potential to expand our knowledge in many life science areas. The course was attended by 34 bachelor and master students from Denmark, the UK, Austria, Germany, Australia, and Belgium.
On May 4th 2016, I spoke about my research at the Aarhus Neuroscience Day - and won the Best Presentation Prize. The purpose of the event was to bridge the gap between basic and clinical neuroscience, to present new research to the Danish public and academia, and to foster collaborations. More than 350 researchers, members of the public, and research foundation and organization representatives attended this year's Neuroscience Day.