Date: Wed, 12 May 2004 12:08:42 -0400 From: Phaedra Royle Subject: Mind, Brain and Language: Multidisciplinary perspectives.
Banich, Marie T. & Molly Mack, ed. (2003) Mind, Brain and Language: Multidisciplinary perspectives, Lawrence Erlbaum Associates.
Phaedra Royle, School of Speech Language Pathology and Audiology, Université de Montréal, Montreal, Quebec, Canada
As stated in the preface of Mind, Brain and Language (hereafter MBL), the aim of this publication is to provide an overview of the influence of the organization of brain structure on language and that of language on thought. The approach is very interdisciplinary, with contributions from the fields of anthropology, psychology, philosophy, neuroscience, and linguistics. The book is designed to be an entry point for researchers who are interested in cross-disciplinary studies, but who have little knowledge of these specific fields. The volume therefore contains chapters written by experts in their various areas of interest, providing us with a glimpse of the cross-disciplinary work done by others. It includes chapters stemming from a conference on Mind, Brain and Language that was held at the University of Illinois in 1998. It is divided into five sections. The first, ''The emergence, Influence and Development of Language,'' focuses on language evolution, language and its effect on thought, language perception and language acquisition. The second section, entitled ''Models of Language and Language Processing,'' describes linguistic and psycholinguistic models of language processing. Section three, ''The Neurological Bases of Language,'' deals with neuroimaging studies of language processing. In section four, ''Language Disruption and Loss,'' developmental and acquired language disorders are expounded, and in section five, ''Two Languages, One Brain,'' the implications of bilingualism on language and brain organization are addressed. I will present each chapter in turn, focusing on the main points addressed. This will be followed by a discussion of certain specific points that I found interesting.
Part I: The Emergence, Influence and Development of Language
1 - Language Evolution and Innateness (Philip Lieberman) In this chapter, Lieberman discusses the evolution of the language faculty and the modularity hypothesis, focusing on the issue of Broca's area and its role in language processing. He rejects the idea that language is modular and states rather that, ''...it can be safely said that the Broca's-Wernicke's area theory first proposed by Lichtheim in 1885 is wrong. [...] Neuroanatomical studies clearly show that permanent aphasia does not occur absent subcortical damage; victims of stroke and other trauma that results in purely cortical damage recover, usually after a period of months (Elman et al., 1997). In contrast, subcortical brain damage can result in permanent linguistic deficits.'' (p.10) Lieberman documents findings in support of his assertion, showing that the language system is a complex neuronal network involving less traditional language areas such as the basal ganglia, the prefrontal cortex, and areas of the primary visual and auditory cortex in addition to Broca's and Wernicke's areas.
2 - Language, Mind and Culture: From Linguistic Relativity to Representational Modularity (Giovanni Bennardo) Bennardo reviews a study on the Linguistic Relativity paradigm (often termed the Sapir-Whorf hypothesis). This chapter is extremely well written. The author shows less informed readers why research on vocabulary items (e.g., color and kinship terms) might not be the best approach to studying the influence of language on thought. He discusses the impact of other cognitive systems on language structure. In particular, he presents data on the interaction of cultural knowledge, conceptual (semantic) knowledge, and spatial representation.
3 - The Role of Speech Perception Capacities in Early Language Acquisition (Peter W. Jusczyk) In this chapter, Jusczyk gives an overview of the research findings on infant speech perception over the last 30 years. The focus is on children who are still in their first year of life. Jusczyk presents information on the attrition of the ability to perceive non-native contrasts, the development of sensitivity to mother-tongue phonotactic and prosodic cues, and the emerging ability to segment the sound stream into words and eventually into phrases. The hope is that such data will provide us with information on how the perception of language constrains models of language acquisition.
Part II: Models of Language and Language Processing
4 - Dissociation and Modularity: Reflections on Language and Mind (Neil Smith) In this chapter, Smith documents findings on language disorders in support of a modular view of language in the brain. By using dissociation data (i.e., the absence of some cognitive ability in the presence of another one in a given individual), he sets out to show that language is modular and can therefore be dissociated from other cognitive processes. The debate centers on the dissociability of language and intelligence. However, cases of people with low intelligence and good language skills are rare. Smith argues that the case of the polyglot savant Christopher and his extraordinary language abilities in the absence of a normal I.Q. is evidence of this thesis. Smith argues further that Christopher's linguistic behavior demonstrates an ability to learn new lexical items and morphological processes such as inflection, but an inability to acquire the syntax of a new language. According to Smith, this suggests the possibility of modularity within language (i.e., separate modules for at least syntax, morphology, and lexicon).
5 - Linguistic Models (Geoffrey K. Pullum & Barbara C. Scholz) Pullum and Scholz present a discussion of syntactic models of language, which they term generative-enumerative (hereafter GU) grammars. They note that GU grammars pose a problem for the theory, as they cannot make a principled distinction between different levels of ungrammaticality, especially in cases where structures are partially grammatical. Another, more important, problem with GU grammars is that it is mathematically impossible to use them to acquire ''superfinite'' grammars (i.e. grammars containing all the finite languages and at least one infinite grammar), at least not from text. The authors propose that the problem with linguistics modeling stems from the fact that linguists try to model sets of expressions rather than the expressions themselves. They propose the use of model-theoretic grammars to overcome this problem. These models are based on GU grammars, but do not have a set-generating component and would instead include constraints on syntactic structures.
6 - Connectionist Modeling of Language: Examples and Implications (David C. Plaut) Plaut reviews three connectionist models of language: one each for phonology (Plaut & Kello, 1999), morphology (Joanisse & Seidenberg, 1999), and syntax (St. John & McClelland, 1990). The main thrust of connectionist models is to account for language processing without cognitive specialization (or modularity). What linguists call ''rules'' are believed here to arise as a consequence of the data (or ''learning''). That is, the acquisition of the past tense in English is not the acquisition of a symbolic structure manipulation process, but rather the statistical strengthening of a predominant pattern that is associated with a constant semantics. There are no morphemes in connectionist models, only the co-occurrence of phonology and semantics. Plaut proposes that connectionist modeling is a compelling method for the comprehension of language processing because it can account for the ''flexibility and productivity of human performance through the development of internal representations that capture the underlying structure in a domain, and because it suggests how such representations and processes might actually be learned and carried out by the brain.'' (p.163)
Part III: The Neurological Bases of Language
7 - Language in Microvolts (Marta Kutas & Bernadette M. Schmitt) Kutas and Schmitt present an overview of the electrophysiology of language processing. They establish the time-course, localization (in terms of scalp electrodes), and strength of the different cognitive processes involved in language recognition and production. The primary interest of evoked response potentials (ERPs) is that they are extremely sensitive to the unfolding time-course of language processing, and that this methodology is non-invasive. ERP recordings have been proven sensitive to phonological, syntactic, and semantic information during processing. In addition, ERP readings can be taken without asking the participant to perform a linguistic task such as grammaticality judgment or lexical decision, thus reducing artifacts related to metalinguistic processing.
8 - Functional and Structural Imaging in the Study of Auditory Language Processes (Robert J. Zatorre) Zatorre reports some findings from brain imaging and neuroanatomical studies of auditory processing in order to better qualify the classical Broca/Wernicke (or production versus comprehension) distinction. He reviews a number of very specific experiments whose goal was to grasp the specific implication of different neuronal substrates in different language processing tasks. Zatorre suggests that Broca's area might also be implicated in the auditory comprehension of language at the level of phonetics.
9 - Parallel Systems for Processing Language: Hemispheric Complementarity in the Normal Brain (Christine Chiarello) Chiarello discusses the question: ''one or two brains?'' which is rarely addressed in the linguistics or even the psycholinguistic literature although it is a hot topic in neurolinguistics and neuro-cognition. While it is clear that, in normal left-handed white males, the left hemisphere (LH) tends to be the superior language processor, it can be shown that both brains carry out linguistic functions in different but complimentary ways. Chiarello presents studies of commissurotomized (split-brain) patients in order to highlight differences in processing at the auditory, semantic, and syntactic levels. She concludes that the LH is an efficient language processor, rapidly zooming in on higher- level information in order to process the message, while the right hemisphere (RH) tends to be more superficial and broad in its language processing capabilities. The LH is also faster than the RH in terms of processing time. Finally, the LH tends to focus on specific meanings for words, while the RH maintains alternative meanings, probably as a fallback procedure if communication breaks down.
Part IV: Language Disruption and Loss
10 - Evidence From Language Breakdown: Implications for the Neural and Functional Organization of Language (Eleanor M. Saffran) Saffran reviews data on language breakdown following cerebral lesions in order to extract information that reveals the functional organization of language in the brain. This chapter focuses on three areas of language: syntactic processing, conceptual organization (semantics), and lexical storage and processing. Based on the data presented, more particularly specific deficits following localized lesions, Saffran concludes that the neural substrate is specialized in identifiable regions of the brain for specific linguistics functions, but that interaction nonetheless takes place between different areas in order to produce and comprehend language.
11 - Neurocognitive Bases of Developmental Reading Disorders (Marie T. Banich & Paige E. Scalf)
Banich and Scalf review three main hypotheses for the neurocognitive basis for developmental dyslexia: disrupted phonological processing, difficulties in temporal or perceptual processing, or a disconnection between brain areas dedicated to reading even if these areas function normally. They present data derived mainly from neuropsychological and neuroanatomical research on developmental dyslexia. The authors note that dyslexia might be the result of one or a number of possible neuroanatomical disturbances, especially in view of the fact that different types of developmental dyslexia exist, and therefore different possible neurocognitive causes.
Part V: Two Languages, One Brain
12 - The Phonetic Systems of Bilinguals (Molly Mack) Mack reviews studies of phonetics in bilinguals. She divides the studies into three different approaches according to their methodologies. The first is the ''monolingual-comparison'' approach, where the bilingual's phonetic system is compared to that of the monolingual in order to find out if the two systems differ. The second, the ''shared-separate'' approach, tries to verify whether the bilingual's phonological systems are shared or independent. The third approach, which she terms the ''age-effect'' approach, investigates more closely the effects of age of acquisition on the ability to learn a second phonetic system. The chapter presents an extensive review of the data and three models that have been proposed to account for them. However, no model can yet account for all of the phenomena observed. Mack also notes, ''very few bilinguals [...] will be found to function at the phonetic level exactly as native monolinguals. This is due at least in part to the inevitable influence [...] of one system upon the other.'' My own experience as a quasi-late learner (5 years old) of French can attest to this. My English stress and aspiration patterns have been strongly modified in favor of French rules.
13 - Differential Use of Cerebral Mechanisms in Bilinguals (Michel Paradis) Paradis presents an overview of his model of neurolinguistics, which is made up of implicit linguistic competence (traditional linguistically motivated components -- what we know but can't say) and explicit metalinguistic knowledge (or declarative knowledge: what we can say we know), which is at least partly responsible for some aspects of lexical knowledge. He adds that pragmatic competence is needed for the normal production of language. Paradis presents a review of neurolinguistic data on language processing in bilinguals that lends support to his model and also shows that type of bilingualism (early vs. late) and learning style (incidental vs. explicit) are important factors in neural organization and representation of language(s).
The main interest in this book lies in the apparent ongoing ''discussion'' between the authors of the different chapters. Two hypotheses are repeatedly presented throughout the book: connectionist (i.e., non-differentiated cognitive processes) versus modular (i.e., specialized cognitive processes) neurocognitive organization. Researchers from different areas present their arguments for or against either model and refer to other chapters in the book in support of their position. In addition, a number of the authors go the extra mile by pointing out overlaps between their area(s) of research and those of the other authors, and they refer to other chapters for a more in-depth discussion of details not addressed by their own section. This makes for a nicely integrated book, especially when we consider that the chapters cover a number of issues from quite disparate areas of research.
As stated in the advertisement for the book, it can be used for readings in a graduate level course or as an introduction to areas of interdisciplinary research for researchers who want to expand their horizons. I was especially intrigued by recent developments in the linguistics relativity paradigm as outlined in chapter 2 by Giovanni Bennardo, since this is an area of linguistic research that I have not followed closely.
A number of thoughts also arose during my readings, in particular with respect to the discussions of the relative merits of modularity vs. connectionism. This issue came up explicitly or implicitly in a number of chapters. For example, in Chapter 2, Lieberman states that, since numerous brain structures support the production of language (and not just Broca's area, as was once thought), we cannot accept a modularistic view of language in the brain. It is important, however, to note that no proponent of modularity has stated that this implies neuroanatomical localization. Strict localization is a straw man that can easily be burned, and I believe that this type of argument against modularity does not add to the scientific debate in any meaningful way.
Another ''linguistic'' fallacy that never ceases to amaze me is the occasional characterization of linguistic models by some psycholinguists as explicit. Some authors genuinely hold the notion that linguistic rules are explicit (i.e., what we can say we know). This, I think, is a gross misrepresentation of the domain of linguistics. Even though we might explicitly formalize rules -- that is write them out as logical structures in the form of ''in the past, add - ed,'' or ''aspirate voiceless stops in stressed onsets,'' linguists do not generally propose that this is how a child learns language or how we represent rules. Linguistic rules are believed to be highly abstract and implicitly represented, as discussed by Paradis in this book. This misrepresentation is unfortunate, since it is often perpetuated in psycholinguistic textbooks that are not used or reviewed by linguists. If not corrected, they propagate a notion akin to the great Eskimo Vocabulary Hoax (Pullum, 1991).
Elman, J., Bates, E., Johnson, M., Karmiloff-Smith, A., Parisi, D. & Plunkett, K. (1997). Rethinking Innateness: A connectionist perspective on development. Cambridge, MA: MIT Press/Bradford Books.
Joanisse, M. & Seidenberg, M. S. (1999). Impairments in brain morphology after brain injury: A connectionist model. Proceedings of the National Academy of Science, 96, 7592-7592.
Plaut, D. C. & Kello, C. T. (1999). The interplay of speech comprehension and production in phonological development: A forward modeling approach. In B. MacWhinney (Ed.), The emergence of language (pp. 381-415). Mahwah, NJ: Lawrence Erlbaum.
Pullum, G. K. (1991). The Great Eskimo Vocabulary Hoax and Other Irreverent Essays on the Study of Language. Chicago: University of Chicago Press.
St. John, M. F. & McClelland, J. L. (1990). Learning and applying contextual constraints in sentence comprehension. Artificial Intelligence, 46, 217-257.
ABOUT THE REVIEWER:
ABOUT THE REVIEWER
Phaedra Royle holds a Ph.D. in Linguistics from the Université de Montréal. Her interests lie in psycholinguistics, language disorders (Specific Language Impairment), language acquisition and morphology. Her thesis investigated lexical access in language-impaired French- speaking adolescents and adults. Her postdoctoral research focused on early language acquisition in French-speaking children with and without language delay at the School of Communication Sciences and Disorders, McGill University. She is presently teaching and carrying out research on language acquisition and processing in French-Speaking populations with and without language disorders at the School of Speech Language Pathology and Audiology at Université de Montréal.