- A Neurolinguistic Theory of Bilingualism
Michel Paradis is an internationally known researcher who has worked on bilingualism, bilingual aphasia, and psycholinguistics for almost three decades. This book presents a synthesis of Paradis's views on a number of fundamental issues in these fields. Those who have followed Paradis's work will recognize a number of familiar themes: no difference between bilinguals and unilinguals with respect to lateralization or localization, the need for aphasia tests specifically designed for bilinguals, deep scepticism about psycholinguistic or psychological gadgetry, etc. This is not a neutral reference work that carefully examines arguments and counter-arguments; Paradis is a scholar of strong opinions who is not afraid to state that entire areas of scientific research are hopelessly misguided.
Paradis's book contains seven chapters. Chapter 1, 'Components of Verbal Communication,' provides an overview of the distinction between implicit and explicit memory applied to language processing and acquisition. Paradis then briefly discusses the anatomical representation of language, the role of pragmatics and the right hemisphere, cultural aspects of communication, motivation in second-language learning, and the Activation Threshold Hypothesis.
Chapter 2, 'Implicit and Explicit Language Processes,' develops further Paradis's proposal that the difference between implicit and explicit processing is crucial to understanding bilingual language behaviour.
Chapter 3, 'Bilingual Aphasia,' summarizes the different recovery patterns observed in bilingual aphasics and then examines reports of bilingual aphasics who are said to have different types of aphasia in different languages. Paradis dismisses all such claims of differential recovery, [End Page 186] claiming that they have misinterpreted the aphasic syndromes involved. He then presents in some detail the Bilingual Aphasia Test and follows with a review of studies on speech therapy for bilingual aphasics.
Chapter 4, 'Cerebral Lateralization and Localization,' examines the numerous psychological studies on the representation of language in the brain. Paradis is deeply critical of the claims of experimental psychologists using dichotic listening tests, visual field preference, etc. and finds that the general validity of lateralization studies is highly questionable. He then dismisses reports of a higher rate of crossed aphasia (aphasia with right hemisphere lesion) in bilinguals and states that there is no clinical evidence from bilinguals that proves a greater degree of right hemisphere participation in language. For Paradis, the left hemisphere is dominant for language in both unilinguals and bilinguals. He is also sceptical of claims that bilinguals have a larger or more diffuse language area in the left hemisphere and concludes this chapter by stating that there are no qualitative differences between bilinguals and unilinguals.
Chapter 5, 'Neurofunctional Modularity,' presents an account of the organization of the brain within the framework laid out by Jerry Fodor. According to Paradis, the brain in general and language in particular is organized into semi-autonomous but interconnected modules.
In chapter 6, 'Neuro-Imaging Studies of the Bilingual Brain,' Paradis delivers his most scathing criticism directed at researchers working with brain-imaging techniques. He finds that the results of studies using techniques such as fMRI (functional Magnetic Resonance Imaging) and PET (Positron Emission Tomography) are based on naïve assumptions about language and on methodology that is totally irrelevant for investigating cognitive functions.
The final chapter, 'An Integrated Neurolinguistic Perspective on Bilingualism,' guides the reader through seven working hypotheses that Paradis has developed: the Three Store hypothesis, the Subsystems hypothesis, the Activation Threshold hypothesis, the Direct Access hypothesis, the use of Implicit linguistic competence and metalinguistic knowledge, the role of Pragmatics, and the role of motivation. For Paradis, the integrated functioning of these hypotheses accounts for the paradoxical or unusual facts about bilinguals. In sum, Paradis dispenses with many fashionable but untenable hypotheses on bilingualism and focuses future research on the areas identified above.
While the book is well documented (a forty-four-page bibliography) and written in an engaging style, it is regrettable that Paradis does not provide more specific details about how his hypotheses apply to language processing in bilingualism. Overall this work raises a number of interesting questions for future research: How does activation take place at the sentence level? How are implicit and...