DOCSLIB.ORG

A New Paradigm for BCI Research

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A New Paradigm for BCI Research A new paradigm for BCI research Conference or Workshop Item Other Submited paper on BCI research Daly, I., Nasuto, S. and Warwick, K. (2008) A new paradigm for BCI research. In: SSE Systems Engineering Conference 2008, 25-26 Sep 2008, The University of Reading. (Unpublished) Available at http://centaur.reading.ac.uk/1076/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online A new paradigm for BCI research Ian Daly and Slawek J. Nasuto and Kevin Warwick1 Abstract. A new control paradigm for Brain Computer Interfaces the keyboard and the mouse. However an expanding field of cur- (BCIs) is proposed. rent research involves methods for directly interfacing between the BCIs provide a means of communication direct from the brain t a brain and a computer, bypassing motor movement control. Such di- computer that allows individuals with motor disabilities an additional rect interfacing opens up the possibility for additional channels of channel of communication and control of their external environment. communication and environmental control for individuals with mo- Traditional BCI control paradigms use motor imagery, frequency tor disabilities. rhythm modification or the Event Related Potential (ERP) as a means It should be noted at this stage that systems interfacing with the of extracting a control signal. brain can be classified as Brain Machine Interfaces (BMIs), where A new control paradigm for BCIs based on speech imagery is ini- BMIs usually refer to invasive interfacing and signal extraction tech- tially proposed. niques, and Brain Computer Interfaces (BCIs), which commonly re- Further to this a unique system for identifying correlations be- fer to noninvasive techniques [33]. However to avoid overly verbose tween components of the EEG and target events is proposed and in- language here we simply refer to all Brain Computer and Brain Ma- troduced. chine Interfaces as BCIs. BCI components can be broken down into five broad areas, these 1 Introduction are. Investigations into the possibility of creating a speech imagery based 1. Signal extraction. BCI are described. Such a BCI allows a degree of control of a com- 2. Signal processing techniques. puter system by the user without the need for muscle movement. 3. Feature extraction. Thus individuals with motor disabilities would be able to use the 4. Classification techniques. system to communicate and control their immediate environment. 5. Control paradigms. A speech imagery based BCI has several advantages over tradi- Signal extraction refers to the reading of levels of neurological tional BCI control paradigms. activity from individuals with the aim of extracting a useful control signal for our BCI. This can take two general forms, either invasive 1. It’s a more natural way for the user to communicate. Imagining techniques such as implanted electrode arrays or non-invasive tech- words is a much more direct means of communication then imag- niques such as the EEG. ing hand movements which is then used to control a cursor to Signal processing refers to the intermediate steps taken between ex- (among other things) select letters to spell a word. tracting a signal and classifying it. The techniques that can be used 2. No training is required on the part of the user. This reduces setup here are many and vary significantly depending on the type of signal time and increases user motivation. extraction method and specific hardware used. They can also depend 3. It’s a much more direct means of control for the user. Thus the user on the intended usage of our signal. However the general aim is al- will have a greater level of success and hence be more motivated ways to maximize the signal to noise ratio with respect to the features to use the system. of the signal that are the most interesting and usable for our purposes. Towards this end it becomes necessary to identify correlations Signal types within BCI encompass both the type of signal ex- within the EEG between speech imagery of specific words and cer- tracted and the way that signal is used. There are many different tain features of the EEG. Thus a unique solution to identifying these types of signals that can be extracted from the brain, these include correlations is outlined. EEG rhythms such as the mu rhythm (related to motor movement), Such a solution has numerous advantages to other researchers in neural firing spike trains (from invasive signal extraction methods), the BCI field. Hence our motivation is to create a unique solution for event related potentials and many more. identifying correlations between EEG features and specific tasks. Classification follows on from signal processing. Classification at- In researching such systems current methods within the BCI field tempts to determine whether a specific signal belongs to a specific are first identified. class group. That is; what command or stimulus presentation a spe- cific signal feature corresponds to. There are two paradigms for control of BCI systems; control based 1.1 Current BCIs - background paradigms and the goal based paradigms. Goal based BCIs present a selection of options to the user. The Traditional methods for interacting with computers are based on mo- user then chooses one of them as their target [33]. For example; in tor movement controlled interfaces. The most common of which are a BCI speller the subject will be presented with a selection of letters 1 University of Reading, UK, email: [email protected] from which they select the one they want. tween them. Damage to any region in this area would lead to aphasia (language disorders). From this theory naturally emerges the idea of functional local- ization within the brain. That is, we attribute specific localized areas specific functions, Broca’s area performs speech production, Wer- nicke’s area speech perception and together they are responsible for language. This idea was further strengthened by the formulation of a much more detailed model of the different specialized areas of lan- guage localization within the brain by Salomon Henschen in 1926 [15]. This model was based on previous clinical studies of patients with aphasia and the specific localization of lesions within their brains. The model has been elaborated on in further studies with even more specific sites added to the map of the brain developed by Brod- mann [20]. It’s important to note that there can be said to exist a level of local- ization of function within the brain. For example damage to Broca’s area will most likely result in loss of speech production abilities, al- though the extent of the loss of function and which specific speech functions are lost is still the subject of much research. It can how- ever be said with a very high level of confidence that when a subject speaks a high level of activity will occur within Broca’s area and when a subject listens to speech a high level of activity will occur Figure 1. Figure 1.0 - Typical EEG recording within Wernicke’s area. Furthermore it has been shown that this ac- tivity can be detected via EEG [6] using wavelet decomposition and independent component analysis to reveal high levels of EEG activity Control based BCIs by contrast allow the user to set their own within certain components at times corresponding to speech percep- goals [33]. For example; many motor imagery based BCIs such as tion. [7] make use of this paradigm. With these systems the user attempts Other research into EEG analysis of language has shown a level of to position a cursor or prosthetic device in any location. Typically the similarity between the mental rehearsal (imagination) of a language cursor or prosthetic’s velocity along one or more directional axis is function and it’s implementation [5]. This is akin to the level of sim- controlled by the strength of some neurological signal component. ilarity exhibited between the mental imagery of a motor function and We can thus say that goal based BCIs are discrete, digital systems it’s implementation [19]. It is upon this principle that the majority of and control based BCIs are open, analog systems. the current BCI research into motor control is based. Additionally fMRI is shown to exhibit specific activity patterns during linguistics tasks such as word perception and production. 1.2 Neurolinguistics Analysis of EEG using fuzzy logic to classify wavelet decompo- Of key importance for attempts to develop a speech production based sitions of the signal is shown to correctly classify speech imagery BCI is the current research into neurolinguistics. That is, research tasks fr three simple nouns (colour names; red, green and blue). This into the neurological mechanisms of speech perception and produc- demonstrates that it is possible to use a range of imaging techniques tion. Therefore the following introduces relevant neurolinguistic con- to identify neurological processes related to speech perception and cepts. production. Further to this it is possible to correctly identify the per- The key areas in the brain involved in speech are Broca’s area ception and imagined production of different words in the EEG. which lies on the third convolution in the left brain hemisphere and It is therefore reasonable to hypothesize that a BCI based upon the was first identified by Paul Broca in 1861 [29]. This region has been imagination of speech production is a feasible area of research.
Load more

Recommended publications
  • Defining the Relation Between Linguistics and Neuroscience
    Defining the relation between linguistics and 6 neuroscience David Poeppel and David Embick University of Maryland College Park and University of Pennsylvania The popularity of the study of language and the brain is evident from the large number of studies published in the last 15 or so years that have used PET, fMRI, EEG, MEG, TMS, or NIRS to investigate aspects of brain and language, in linguistic domains ranging from phonetics to discourse processing. The amount of resources devoted to such studies suggests that they are motivated by a viable and successful research program, and implies that substantive progress is being made. At the very least, the amount and vigor of such research implies that something significant is being learned. In this article, we present a critique of the dominant research program, and provide a cautionary perspective that challenges the belief that explanatorily significant progress is already being made. Our critique focuses on the question of whether current brain/language research provides an example of interdisciplinary cross-fertilization, or an example of cross-sterilization. In developing our critique, which is in part motivated by the necessity to examine the presuppositions of our own work (e.g. Embick, Marantz, Miyashita, O'Neil, Sakai, 2000; Embick, Hackl, Schaeffer, Kelepir, Marantz, 2001; Poeppel, 1996; Poeppel et al. 2004), we identify fundamental problems that must be addressed if progress is to be made in this area of inquiry. We conclude with the outline of a research program that constitutes an attempt to overcome these problems, at the core of which lies the notion of computation.
    [Show full text]
  • Neural Representational Similarity Between Symbolic and Non-Symbolic Quantities Predicts Arithmetic Skills in Childhood but Not Adolescence
    Received: 29 July 2020 Revised: 1 April 2021 Accepted: 3 May 2021 DOI: 10.1111/desc.13123 SHORT REPORT Neural representational similarity between symbolic and non-symbolic quantities predicts arithmetic skills in childhood but not adolescence Flora Schwartz1 Yuan Zhang1 Hyesang Chang1 Shelby Karraker1 Julia Boram Kang1 Vinod Menon1,2,3,4 1 Department of Psychiatry and Behavioral Sciences, Stanford University School of Abstract Medicine, Stanford, California, USA Mathematical knowledge is constructed hierarchically from basic understanding of 2 Department of Neurology and Neurological quantities and the symbols that denote them. Discrimination of numerical quantity in Sciences, Stanford University School of Medicine, Stanford, California, USA both symbolic and non-symbolic formats has been linked to mathematical problem- 3 Stanford Neuroscience InstituteStanford solving abilities. However, little is known of the extent to which overlap in quantity University School of Medicine, Stanford, California, USA representations between symbolic and non-symbolic formats is related to individual 4 Symbolic Systems Program, Stanford differences in numerical problem solving and whether this relation changes with dif- University School of Medicine, Stanford, ferent stages of development and skill acquisition. Here we investigate the association California, USA between neural representational similarity (NRS) across symbolic and non-symbolic Correspondence quantity discrimination and arithmetic problem-solving skills in early and late devel- Vinod Menon, Stanford University School of opmental stages: elementary school children (ages 7–10 years) and adolescents and Medicine, 401 Quarry Rd, Stanford, CA 94305, USA. young adults (AYA, ages 14–21 years). In children, cross-format NRS in distributed Email: [email protected] brain regions, including parietal and frontal cortices and the hippocampus, was posi- Flora Schwartz, Yuan Zhang, and Hyesang tively correlated with arithmetic skills.
    [Show full text]
  • Jyoti Mishra, Ph.D
    Contact CURRICULUM VITAE UCSF - Mission Bay Sandler Neurosciences Center Rm 502 Jyoti Mishra, Ph.D 675 Nelson Rising Lane San Francisco, CA 94158-0444 Web: http://profiles.ucsf.edu/jyoti.mishra http://gazzaleylab.ucsf.edu/people-profiles/jyoti-mishra/ Email: [email protected] [email protected] Phone: 415-502-7322 Personal Statement I am a translational neuroscientist with expertise in attention, learning and brain plasticity. My research mission is “advancing neurotechnology from the lab to the community”. I develop and evaluate novel neurotechnologies that can serve as neurocognitive diagnostics and therapeutics; in this context, I recently developed novel attention training tools for aging adults and children with attention deficits. My current lab projects focus on advancing real-time neurofeedback technologies and developing neuroscience-based training that optimizes decision-making in children. My community projects evaluate our innovative neurocognitive therapeutics in children with ADHD and neglected children in institutional foster-care, here in the United States as well as in India via global mental health research collaborations. Positions and Employment 2013 - present Assistant Professor Step 2 Departments of Neurology, Psychiatry and Global Health Sciences University of California, San Francisco 2009 - 2014 Senior Scientist, Brain Plasticity Institute PositScience Corporation, San Francisco 2009 - 2012 Postdoctoral Research Fellow, Neurology University of California, San Francisco 2008 - 2009 Postdoctoral Research
    [Show full text]
  • Neurolinguistic and Machine-Learning Perspectives on Direct Speech Bcis for Restoration of Naturalistic Communication
    Brain-Computer Interfaces ISSN: 2326-263X (Print) 2326-2621 (Online) Journal homepage: http://www.tandfonline.com/loi/tbci20 Neurolinguistic and machine-learning perspectives on direct speech BCIs for restoration of naturalistic communication Olga Iljina, Johanna Derix, Robin Tibor Schirrmeister, Andreas Schulze- Bonhage, Peter Auer, Ad Aertsen & Tonio Ball To cite this article: Olga Iljina, Johanna Derix, Robin Tibor Schirrmeister, Andreas Schulze- Bonhage, Peter Auer, Ad Aertsen & Tonio Ball (2017): Neurolinguistic and machine-learning perspectives on direct speech BCIs for restoration of naturalistic communication, Brain-Computer Interfaces, DOI: 10.1080/2326263X.2017.1330611 To link to this article: http://dx.doi.org/10.1080/2326263X.2017.1330611 © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group Published online: 21 Jun 2017. Submit your article to this journal View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=tbci20 Download by: [93.230.60.226] Date: 22 June 2017, At: 15:41 BRAINCOMPUTER INTERFACES, 2017 https://doi.org/10.1080/2326263X.2017.1330611 OPEN ACCESS Neurolinguistic and machine-learning perspectives on direct speech BCIs for restoration of naturalistic communication Olga Iljinaa,b,c,e,g,h, Johanna Derixe,h, Robin Tibor Schirrmeistere,h, Andreas Schulze-Bonhaged,e, Peter Auera,b,c,f, Ad Aertseng,i and Tonio Balle,h aGRK 1624 ‘Frequency effects in language’, University of
    [Show full text]
  • Language, Culture and the Neurobiology of Pain: a Theoretical Exploration
    Behavioural Neurology, 1989, 2, 235-259 Language, Culture and the Neurobiology of Pain: a Theoretical Exploration HORACIO FABREGA, JR. Universiry oj Pittsburgh, School oj Medicine, Department oj Psychiatry, Pittsburgh, Pennsylvania 15213, USA Language and culture, as conceptualized in traditional anthropology, may have an important influence on pain and brain-behavior relations. The paradigm case for the influence of language and culture on perception and cognition is stipulated in the Sapir-Whorfhypothesis which has been applied to phenomena "external" to the individual. In this paper, the paradigm is applied to information the person retrieves from "inside" his body; namely, "noxious" stimuli which get registered in consciousness as pain. Introduction Every person seems to "know" what pain is and by means of language is able to describe it. Given the ubiquity and importance of pain in the adaptation of higher animal forms, one may infer that it has played an important role in evolution. It is thus very likely that pre-hominids and earlier members of the human species also "knew" a great deal about pain. A neurophysiologist would claim that pain is based on brain structures which all members of the human species share. At present these structures and their mode offunctioning are incompletely understood. An anthropolo­ gist who endorses a position of cultural relativism is aware of the variety of beliefs and understandings about pain and behaviors associated with it and would claim that there appear to exist not one but many varieties of pain (Fabrega, 1974; Zborowski, 1958; Fabrega and Tyma, 1976a,b). Language and culture play some role in the phenomenon of pain.
    [Show full text]
  • Neuroscience Impact Brain and Business
    Innovation Trend Report Neuroscience Impact Brain and Business NEUROSCIENCE IMPACT – BRAIN AND BUSINESS INTRODUCTION This work is licensed under a Creative Commons Attribution-NonCommercial- Acknowledgements NoDerivatives 4.0 International. We would like to extend a special thanks to all of the companies and To view a copy of this license, visit: individuals who participated in our Report with any kind of contribution. https://creativecommons.org/licenses/ The following companies agreed to be publicly named and gave us by-nc-nd/4.0/ or send a letter to: Creative precious content to be published: Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. Dreem Neural Sense Emotiv Neuralya Halo Neuroscience Paradromics Mindmaze Pymetrics Neuron Guard Synetiq We would also like to thank the following individuals for helping us with precious suggestions and information: Russel Poldrack, Professor of Psychology at Stanford University, CA, USA; John Dylan-Haynes, Professor at the Bernstein Center for Computational Neuroscience Berlin, Germany; Carlo Miniussi, Director of Center for Mind/Brain Sciences – CIMeC, University of Trento, Rovereto TN Italy; Zaira Cattaneo, Associate Professor in Psychobiology and Physiological Psychology, Department of Psychology, University of Milano-Bicocca, Milano, Italy; Nadia Bolognini, University of Milano Bicocca, Department of Psychology, & IRCCS Istituto Auxologico Italiano, Laboratory of Neuropsychology; Dario Nardi, Author, speaker and expert in the fields of neuroscience and personality; Intesa Sanpaolo Innovation Center Nick Chater, Professor of Behavioral Science at Warwick Business School; assumes no responsibility on the Enrico Maria Cervellati, Associate Professor of Corporate Finance external linked content, both in terms of at the Department of Management Ca’ Foscari University of Venice; availability that of immutability in time.
    [Show full text]
  • Neurophysiological Activity Related to Speech Production: an ERP Investigation Adithya Chandregowda University of South Florida, [email protected]
    University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 11-20-2015 Neurophysiological Activity Related to Speech Production: An ERP Investigation Adithya Chandregowda University of South Florida, [email protected] Follow this and additional works at: http://scholarcommons.usf.edu/etd Part of the Neurosciences Commons, and the Other Psychology Commons Scholar Commons Citation Chandregowda, Adithya, "Neurophysiological Activity Related to Speech Production: An ERP Investigation" (2015). Graduate Theses and Dissertations. http://scholarcommons.usf.edu/etd/5919 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Neurophysiological Activity Related to Speech Production: An ERP Investigation by Adithya Chandregowda A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Communication Sciences and Disorders College of Behavioral and Community Sciences University of South Florida Co-Major Professor: Emanuel Donchin, Ph.D. Co-Major Professor: Yael Arbel, Ph.D. Stefan A. Frisch, Ph.D. Nathan D. Maxfield, Ph.D. Date of Approval: November 20, 2015 Keywords: Speech motor control, Readiness potentials, Principal component analysis Copyright © 2015, Adithya Chandregowda TABLE OF CONTENTS LIST OF TABLES ................................................................................................................
    [Show full text]
  • Introduction to Neurolinguistics
    Introduction to Neurolinguistics Aniela Improta França UFRJ (Federal University of Rio de Janeiro, Brazil) This is an account of Introduction to Neurolinguistics, a week-long course that took place during the First South American Summer School in Formal Linguistics (EVELIN ’04), UNICAMP, São Paulo, Brazil. Classes ranged from an overview of brain anatomy and an introduction to neurolinguistics protocols to the comparative analysis of neurolinguistics and medical research about the Language Faculty. 1. About the course Neurolinguistics is a branch of Cognitive Neuroscience, that, on its turn, together with many other fields such as Systemic, Movement, Sensory, Cellular and others, is a branch of a larger domain named the Neurosciences. Neurolinguistics can still be divided into two areas: language acquisition and processing and language impairment. THE NEUROSCIENCES Cognitive Systemic Movement Sensory Cellular Neurolinguistics Vision Hearing Attention Memory Language Acquisition Language Impairment Language Processing The focus on language impairment is a historic one, dating from 400 b.C., with Hippocrates’ accounts on infirmities that produced lack of language. Contrastingly, the questions about the healthy Faculty of Language – how we come to acquire and use our mother tongue – have been systematically taken for granted through a long stretch of history, despite the fact that language is the one cognition that definitely sets us apart from other animals on this planet. In reality, language investigation has only taken a definite bio-linguistic course in the 1950’s with the advent of Noam Chomsky’s Generative Grammar (Chomsky, 1957, 1965). And the neurophysiological characterization of the healthy Faculty of Language, that is, the understanding of language-brain relations at work, only started being investigated specially in the late 1980’s, with the introduction of non-invasive cognitive assessment techniques that brought new and exciting perspectives into the field.
    [Show full text]
  • SEPTEMBER 2018 Vol
    The Journal of the IYNA SEPTEMBER 2018 Vol. 2 Issue 5 Featured Articles ‘Brain Versus Com- ‘The Brain of a puter: A Comparison Honeybee’ of Structure, Meth- - Vilena Lee ods, and Capabilities’ - Khayla Black International Youth Neuroscience Association –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Contents INTRODUCTION Letter from the Editors IYNA Editorial Team page 2 GENERAL NEUROSCIENCE The Brain of a Honeybee Vilena Lee pages 3-7 The Neuroscience Behind Imagination, Kimaya Gadre pages 8-10 or What We Imagine it to be Neurolinguistics: The Intersection of Language Geetanjali Rastogi pages 11-14 and the Brain DISEASE Protein Dysregulation in Amyotrophic Lateral Sarah Shirley p ages 15-17 Sclerosis RESEARCH Oxytocin and Social Cognitive Decits Tobey Le pages 18-20 NEUROTECHNOLOGY Brain versus Computer: A Comparison of Khayla Black pages 21-26 Structure, Methods, and Capabilities INTERVIEW An Interview With Elisabeth Glowatzki: Dharshan Varia pages 27-30 Departments of Otolaryngology and Head and Neck Surgery and Neuroscience at Johns Hopkins University Zebrash and Hearing: An Interview with Dr. Chinmayi Balusu pages 31-35 Allison Con CONTRIBUTORS PAGE page 36 –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1 –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ・I NTRODUCTION ・ –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Letter From the Editors Sojas Wagle, Robert Morgan, Anita Singh, and Miruna-Elena Vlad Dear Readers, Welcome to the fth issue of the second season of the IYNA Journal! We greatly appreciate your readership, continued or new. This is the second issue with our redesigned journal process where we now have a rolling basis for article publications. This means that every article that is submitted before the deadline will not necessarily be published for that specic issue, but publication in a future issue is virtually guaranteed if the author makes changes to their article as directed by the editors’ suggestions.
    [Show full text]
  • Neuromodulation of Cursing in American English a Combined
    Brain and Language 206 (2020) 104791 Contents lists available at ScienceDirect Brain and Language journal homepage: www.elsevier.com/locate/b&l Neuromodulation of cursing in American English: A combined tDCS and T pupillometry study ⁎ Jamie Reillya,b, , Bonnie Zuckermana,b, Alexandra Kellyc, Maurice Fluriea,b, Sagar Raod a Eleanor M. Saffran Center for Cognitive Neuroscience, USA b Department of Communication Sciences and Disorders, Temple University, Philadelphia, PA, USA c Department of Psychology, Drexel University, Philadelphia, PA, USA d Swarthmore College, Swarthmore, PA, USA ARTICLE INFO ABSTRACT Keywords: Many neurological disorders are associated with excessive and/or uncontrolled cursing. The right prefrontal Cursing cortex has long been implicated in a diverse range of cognitive processes that underlie the propensity for cursing, Tabooness including non-propositional language representation, emotion regulation, theory of mind, and affective arousal. Psycholinguistics Neurogenic cursing often poses significant negative social consequences, and there is no known behavioral tDCS intervention for this communicative disorder. We examined whether right vs. left lateralized prefrontal neu- Brain Stimulation rostimultion via tDCS could modulate taboo word production in neurotypical adults. We employed a pre/post design with a bilateral frontal electrode montage. Half the participants received left anodal and right cathodal stimulation; the remainder received the opposite polarity stimulation at the same anatomical loci. We employed physiological (pupillometry) and behavioral (reaction time) dependent measures as participants read aloud taboo and non-taboo words. Pupillary responses demonstrated a crossover reaction, suggestive of modulation of phasic arousal during cursing. Participants in the right anodal condition showed elevated pupil responses for taboo words post stimulation.
    [Show full text]
  • Clinical Neurolinguistics of Bilingualism 739
    36 Clinical Neurolinguistics of B ilingualism A n d r e a M a r i n i, C o s i m o U r g e s i, a n d F r a n c o F a b b r o Introduction The notion of bilingualism refers to all those people who use or simply know two or more languages, including dialects (Grosjean, 1994 ). Just to provide some fi gures, let us consider that something like 7,000 languages are spoken in barely 160 coun- tries. Furthermore, in many of these countries the number of spoken languages is constantly growing due to massive immigration. This means that over 50% of the world population knows at least two languages with different degrees and can be consequently considered not only bilingual but even multilingual (Tucker, 1998 ). The issue of language representation and use in multilingual speakers can be approached at different levels of description. Indeed, it constitutes a matter of inter- est not only for sociolinguistic models of language use and stratifi cation, but also for psycholinguistic theories of language development and functioning, as well as for neurolinguistic models of language representation in the brain, its loss and potential recovery. As such, the issue of bi - /multilingual competence constitutes an important line of research for both clinical and theoretical neurolinguistics (Fabbro, 2001a ). Accordingly, after introducing the issue of the defi nition of multilingual compe- tence, this chapter will explore the loss and recovery patterns in both adult and child bi - /multilingual speakers with different etiologies (aphasias, specifi c language impairment, neuropsychiatric and progressive neurodegenerative disorders).
    [Show full text]
  • Neurolinguistics
    Neurolinguistics 1 What is neurolinguistics? Neurolinguistics studies the relation of language and communication to different aspects of brain function, i.e. it tries to explore how the brain understands and produces language and communication. This involves attempting to combine theory from neurology/neurophysiology (how the brain is structured and how it functions) with linguistic theory (how language is structured and how it functions). • "human language or communication (speech, hearing, reading, writing, or non-verbal modalities) related to any aspect of the brain or brain function" (Brain and Language: "Description") • The common problem area of relating aspects of language or communication to brain function in this dynamic formulation, is stated as a common question by Luria in "Basic problems in neurolinguistics": • "what are the real processes of formation of verbal communication and its comprehension, and what are the components of these processes and the conditions under which they take place" • (Luria, 1976, p.3) Interdisciplinary enterprise • linguistics,neuroanatomy, neurology, neurophysiology, philosophy, psychology, psychiatry, speech pathology and computer science, neurobiology, anthropology, chemistry, cognitive science and artificial intelligence. • Thus, the humanities, as well as medical, natural and social sciences, as well as technology are represented. Different views on the relation between brain and language • Localism tries to find locations or centers in the brain for different language functions. Associationism places language functions in the connections between different areas of the brain, making it possible to associate, for example, perceptions of different senses with words and/or “concepts”. • Dynamic localization of function assumes that functional systems of localized sub-functions perform language functions. Such systems are dynamic, so that they can be reorganized during language development or after a brain damage.
    [Show full text]