The Bilingual Brain: Bilingual Aphasia

Brain and Language 79, 201–210 (2001) doi:10.1006/brln.2001.2480, available online at http://www.idealibrary.com on

The Bilingual Brain: Bilingual Aphasia Franco Fabbro IRCCS ‘‘E. Medea’’ and University of Udine, Udine, Italy

Since most people in the world know more than one language, bilingual aphasia is an important line of research in clinical and theoretical neurolinguistics. From a clinical and ethical viewpoint, it is no longer acceptable that bilingual aphasics be assessed in only one of the languages they know. Bilingual aphasic patients should receive comparable language tests in all their languages. In the present work, language recovery of 20 bilingual Friulian–Italian aphasics was investigated. Thirteen patients (65%) showed a similar impairment in both languages (parallel recovery), four patients (20%) showed a greater impairment of L2, while three patients (15%) showed a greater impairment of L1. Despite the many hypotheses advanced to account for nonparallel recovery, none of them seems to provide satisfactory explanations. The study of bilingual aphasics with parallel impairment of both languages allows us to verify the hypothesis whereby grammatical disorders in aphasia depend on the specific structure of each language. As far as rehabilitation programs for multilingual aphasics are concerned, several questions have been raised, many of which still need a satisfactory answer.  2001 Academic Press

Key Words: bilingual aphasia; language assessment; language recovery; language treatment.

Describing Bilingualism According to current linguistic, psychological, and neurolinguistic approaches, the term ‘‘bilingual’’ refers to all those people who use two or more languages or dialects in their everyday lives (Grosjean 1994). In this presentation, dialects are subsumed under the term ‘‘language.’’ Actually, at the linguistic level no objective criteria to distinguish between languages and dialects have been proposed so far (Pinker 1994), and at the neurolinguistic level the question whether the structural distance between two languages or two dialects or between a language and a dialect may affect their respective cerebral representation is still under debate (Paradis, 1995). Several neuropsychological studies suggest that it is not correct to consider bilingual subjects as ‘‘two monolinguals in one person’’ (Grosjean, 1989). Indeed, bilinguals do not necessarily need to have a perfect knowledge of all the languages they know to be considered as such. The extremist view of the ‘‘perfect’’ bilingual derives from a language culture which is essentially monolingual. Bilinguals acquire and use their languages for different purposes, in different domains of life and with different people. For example, a Canadian born in Quebec may acquire Quebecois as mother tongue (L1) and use it with his or her family and friends; standard French as a second language (L2), being the official language of education; and English as a third (L3) language, the latter not being used everyday but, for example, to write scientific manuscripts or give lectures at international congresses. Irrespective of the degree Address correspondence and reprint requests to Franco Fabbro, Neurolinguistic Unit, Scientific Institute ‘‘E.Medea,’’ 33078 San Vito al Tagliamento (PN), Udine, Italy. E-mail: [email protected]. 201 0093-934X/01 $35.00 Copyright  2001 by Academic Press All rights of reproduction in any form reserved.

202

FRANCO FABBRO

of knowledge this person has of these three languages, he or she should definitely be considered a bilingual. Given these methodological premises, at present more than half of the world population is multilingual (Grosjean 1982, 1994). As a direct consequence, multilingual individuals suffering from developmental or acquired speech or language disorders do not represent isolated and exceptional cases—as one might be inclined to think when reading the specialized literature—but rather the majority of clinical cases (Paradis, 1998a). The Assessment of Bilingual Aphasia A systematic assessment of all the languages known by an aphasic patient is an essential prerequisite for both clinical procedures (diagnosis, rehabilitation program, assessment of progress in recovery, etc.) and neurolinguistic research on multilingualism. For this reason, Michel Paradis and associates (Paradis & Libben, 1987; Paradis, 2001a) developed the Bilingual Aphasia Test (BAT), which consists of three main parts: part A for the evaluation of the patient’s multilingual history (50 items), part B for the systematic and comparable assessment of language disorders in each language known by the subject (472 items in each known language), and part C for the assessment of translation abilities and interference detection in each language pair (58 items each). The BAT is currently available in 65 languages (part B) and 160 language pairs (part C). Parts B and C of this test have not been simply translated into different languages, but rather adapted across languages. For example, when adapting the BAT verbal auditory discrimination test into Friulian, English items were not simply translated. In fact, for each item the authors had to find four Friulian words that differed from each other by only one initial phoneme and could also be easily represented by a picture. Thus, the English stimuli ‘‘mat, cat, bat, hat’’ became ‘‘cjoc, c¸oc, poc, toc’’ (drunk, log, chicory, piece). The persons administering the test are not required to make any judgment: they simply write down the answers given by the patient, which will then be processed by means of a computerized program indicating for each part (B and C) the absolute number and the percentage of correct answers for each linguistic skill (comprehension, repetition, judgment, lexical access, propositionizing, reading, and writing) and for each linguistic level (phonology, morphology, syntax, lexicon, and semantics). For some parts of the test, such as spontaneous speech, description of a short story illustrated by pictures, and spontaneous writing, a thorough neurolinguistic analysis on the basis of strict, objective criteria is required. Assessment of bilingual aphasics by the BAT provides a quantification and classification of language disorders for each language, thus allowing a direct comparison of performances in the different languages known by the patient. Before the BAT, bilingual aphasia was studied using different test instruments; for this reason it was very hard to compare different studies (cf. Paradis, 1983, 1993). Therefore, previous findings should be seen as a useful starting point for a more thorough and systematic neurolinguistic analysis (Fabbro, 1997). As pointed out by Grosjean (1989, 1998) and stipulated in the implementation manual (Paradis & Libben, 1987), when assessing residual language abilities in bilingual aphasics, a series of methodological precautionary steps should be taken: each language should be assessed on a separate day and the code-switching habits of the patient before pathological onset should be thoroughly described, e.g., asking relatives and friends for relevant information. Indeed, in some bilingual communities code switching is sociolinguistically accepted and quite common during everyday conversation (e.g., among English–French bilinguals in Montreal, Canada), whereas

BILINGUAL APHASIA

203

it hardly ever occurs in other bilingual environments (e.g., Friulian–Italian bilinguals in Friuli, cf. Francescato & Salimbeni, 1976). If the patient exhibits frequent pathological switching and/or mixing, L1 should be assessed by a person not knowing the patient’s L2 and, vice versa, L2 should be assessed by someone not knowing L1, so as to avoid confusing any pathological behavior with deep-rooted habits. On the other hand, assessment of translation abilities should be made by someone knowing all the languages at issue. Clinical Aspects of Bilingual Aphasia Several clinical studies have shown that bilingual aphasics do not necessarily manifest the same language disorders with the same degree of severity in both languages. For this reason, it is no longer ethically acceptable to assess aphasic patients in only one of their languages (Paradis 1995). In addition, the clinical assessment of both monolingual and bilingual aphasics should take into account three different phases in time: (1) the acute phase, which generally lasts 4 weeks after onset; (2) the lesion phase, which lasts for several weeks and perhaps even up to 4–5 months postonset; and (3) the late phase, beginning a few months after onset and continuing for the rest of the patient’s life (Alexander, 1989; Fabbro, 1999a). During the acute phase a regression of the diaschisis occurs, i.e., a regression of the functional impairment effects in structurally unaffected cerebral regions of the ipsilateral and/or contralateral hemisphere which are functionally connected to the brain area where the damage occurred. These effects were highlighted by tests based on the quantitative assessment of the regional glucose metabolism by means of positron emission tomography (Cappa, 1988). During the acute phase, several dynamic language disorders were observed, such as temporary mutism with preserved comprehension in both languages (Aglioti & Fabbro, 1993; Fabbro & Paradis, 1995b), severe word-finding difficulties alternately in one language with concurrent relative fluency in the other language and good comprehension in both (the so-called alternating antagonism; cf. Paradis, Goldblum, & Abidi 1982; Nilipour & Ashayeri, 1989), and severe impairment of the language acquired during childhood with complete preservation of the one learned at school (‘‘selective aphasia’’; cf. Paradis & Goldblum, 1989). The study of these dynamic phenomena is also useful for setting up theoretical neurofunctional models of brain functioning in multilinguals (Green, 1986; Paradis, 1993a), though it does not allow us to draw unequivocal conclusions about the relationship between linguistic functions and neuroanatomical structures. The lesion phase is the period of greatest interest for brain–behavior relationships because during this period language disorders can be more clearly correlated with the site and extent of the lesion. Since such disorders are also more stable, it is far more convenient to carry out a complete assessment of the patients’ residual language abilities in this phase by taking into account all the languages he or she knew before the insult. Aphasic disorders may or may not vary across languages in one and the same patient; they may be classified as typical of a single aphasic syndrome, though with different degrees of symptomatic severity according to the language (Fabbro & Paradis, 1995b; Yiu & Worral, 1996). On the other hand, the hypothesis of the existence of a clinical picture of differential aphasia (Albert & Obler, 1978; Silverberg & Gordon, 1979), namely a type of aphasia in one language (e.g., Wernicke’s aphasia) and another type (e.g., Broca’s aphasia) in another language, still lacks sufficient corroborating data (Paradis, 1998b). In the late phase different patterns of recovery can be observed in multilingual patients. Sometimes, this phase may hardly differ from the previous one since recovery or even improvement do not always occur. Language recovery phenomena are

204

FRANCO FABBRO

thought to be due to the ‘‘takeover’’ of linguistic functions by the contralateral hemisphere or by undamaged areas within the same hemisphere (Bychowsky, 1919/1983; Cappa, 1998). Improvement in communication skills may probably depend on the application of explicit compensatory strategies (Paradis, 1994; Paradis & Gopnik, 1997). Recovery, either spontaneous or following rehabilitation, may continue also during the late phase, though generally less intensively than during the lesion phase. Patients should be periodically reassessed so as to reexamine recovery patterns and possibly revise the rehabilitation program. The most common patterns of recovery, described by Pitres (1895) in the first monograph on bilingual aphasia ever published, are (1) parallel recovery, when both languages are recovered simultaneously; (2) selective recovery, when only one language slowly comes back and the other is never recovered; and (3) successive recovery, when one language improves before the other(s). Language Recovery in Polyglot Aphasics When bilinguals or polyglots suffer a brain insult affecting language areas, they may lose the ability to use all languages they knew and exhibit the same type of aphasia in all languages. Subsequent recovery may be parallel in all languages. In a study on the literature of bilingual aphasia published in 1977, Paradis stated that 40% of the reported cases of polyglot aphasics exhibited parallel recovery of languages. It should be noted, however, that these statistics are based on clinical case histories which have been published and, thus, are the most atypical. Paradis put forward the hypothesis that this type of recovery is even more frequent because descriptions of single clinical cases of polyglot aphasics with parallel language recovery are very rare, since neurologists and neuropsychologists tend to describe ‘‘exceptional’’ cases only, as they can more easily be published (Paradis, 1977). This is one of the reasons why over 10 years ago Paradis started an international project on bilingual aphasia in Canada, which is still operative and sees the participation of numerous researchers from all over the world. This study also includes bilingual aphasic patients with any type of language disorders so as to have a large number of subjects and, thus, more reliable statistical data. In some cases, aphasia affects only one of the languages known by the patient. In his study of 1895, Pitres was the first to draw attention to the fact that the dissociation of the languages affected by aphasia was not an exceptional phenomenon, but rather ordinary. Pitres described seven clinical cases of patients exhibiting differential recovery of the two languages they spoke. On the basis of the frequency of dissociation, Pitres put forward hypotheses on the causes that might determine a better recovery in one language. He suggested that patients tended to recover the language that was most familiar to them prior to the insult. This hypothesis was subsequently called Pitres’ rule. In proposing his theory, Pitres referred to a work by Ribot in which it was claimed that, in the case of memory disorders, the general rule held that the new deteriorates earlier than the old. Subsequently, numerous neurologists compared and contrasted the so-called Pitres’ rule (recovery of the most familiar language) with ‘‘Ribot’s law’’ (recovery of the native language), but it should be noted that none of the two authors ever formulated a ‘‘rule’’ on language recovery in bilingual aphasics. In his work, Pitres proposed a reasonable explanation of language recovery in aphasics. He maintained that the recovery pattern could occur only if the lesion had not destroyed language centers, but only temporarily inhibited them through pathological inertia. In Pitres’ opinion, the patient generally recovered the most familiar language because the neural elements subserving it were more firmly associated. If the patient had become aphasic owing to ‘‘functional inertia’’ of the language areas,

BILINGUAL APHASIA

205

these inhibitory pathological phenomena should have affected to a greater extent the languages that exhibited weaker associations between the neural elements subserving them. These hypotheses were both supported and opposed. To date, no unequivocal evidence supports a rule applicable to all clinical cases. Language Recovery in 20 Friulian–Italian Bilingual Aphasics In recent years I have had the opportunity to assess 20 right-handed bilingual aphasics using the Bilingual Aphasia Test—BAT (Paradis and Libben 1987, 1999) in the two versions of Friulian (Paradis & Fabbro, 1993) and Italian (Paradis & Canzanella, 1989). Table 1 shows patients’ percentages of correct tasks in the BAT linguistic levels both in L1 and L2. All the patients presented with aphasia following a left hemisphere lesion. Seventeen patients were native Friulians and three patients were native Italians (OM, AS, and CM in Table 1). For all patients L2 was learned between 5 and 7 years of age. Before the insult all patients used both languages in their everyday lives. They could write and read only in Italian. A battery of standardized neuropsychological tests for the assessment of orientation in time and space, attention, detection of agnosia, apraxia, verbal and spatial short-term memory deficits, and verbal long-term memory deficits was administered to all patients (Spinnler & Tognoni, 1987). Furthermore, patients received a standard neurologic examination and a neuroimaging study was performed with CT scan or MRI to define the characteristics of the lesion (site, extent, and type, see Table 1). Eighteen patients (except for KB and CM) also received the Italian version of the Aachener Aphasie Test—AAT (Luzzati et al., 1992) to determine the type of aphasia which had affected each patient (see Table 1). Thirteen patients (65%) showed a similar impairment in both languages (parallel recovery) (subjects 1–13, Table 1), four patients (20%) showed a greater impairment of L2 (subjects 14–17, Table 1), while three patients (15%) showed a greater impairment of L1 (subjects 18–20, Table 1). These percentages are in line with a recent review on language recovery in polyglot aphasics (Paradis, 2001b). Several factors have been proposed to explain parallel language recovery vs differential recovery in bilinguals. The native language, the most familiar to the patient at the time of the insult, the most socially useful or the most affectively loaded, or, still, the language of the environment do not recover first or best. Nor does it seem to be a matter of whether the two languages were acquired and used in the same context as opposed to different contexts, at different times of development (Paradis 1977, 1998, 2001b). Still, the type of aphasic syndrome, the type of lesion (tumor, infarction, or cerebral hemorrhage) or the site of the lesion (cortical vs subcortical, frontal lobe vs temporal lobe, etc.) do not seem to be directly responsible for parallel language recovery vs differential recovery. So far, empirical studies have not provided tenable explanations for the presence of parallel recovery in some bilingual aphasic patients and of differential recovery in others. Grammatical Errors in Bilingual Aphasic Patients Grammatical deficits in aphasia are dependent on the way the system can break down and, therefore, on the structure of the language system. When the system is placed under stress it can only break down at those junctures allowed by the system (Paradis, 1988). Given this assumption, if inflectional morphology is vulnerable, a language with this feature will show outstanding signs of agrammatism (Alajouanine, 1968). Grammatical disorders typical of aphasia are dependent on the structure of each language. Their various manifestations are only trivially (and predictably) differ-

F F M M M M F M M M M M F F F M M M F M

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

15 71 56 63 39 50 77 48 67 62 72 51 25 67 54 54 48 53 78 77

A 8 5 11 5 18 13 5 13 5 5 8 19 13 5 5 8 17 5 8 5

Edu I I H I Tu H I I I I I I H Tu I I H I I I

TL FT BG BG BG-I Th BG T FT BG Ins T BG PT Th BG P BG-FT PT PT F

Ls 96 4 28 3 3 1 1 3 2 1 1 7 13 1 1 4 1 24 1 1

Ass TM B B W-B A-B B B B W-A B-A G B A TM A G G TS W G

95 81 79 75 96 82 71 51 81 95 76 87 93 95 89 61 48 67 59 48

L1 95 76 82 78 95 85 67 62 73 82 76 79 100 95 89 39 45 89 62 61

L2 65 52 13 43 91 56 26 0 52 78 65 78 95 86 86 56 13 17 30 0

L1 69 43 69 43 78 73 17 68 21 86 65 78 65 56 65 17 4 17 60 39

L2

Morphology

88 51 50 53 75 58 58 66 58 95 69 78 89 91 86 44 55 50 60 36

L1 93 55 56 50 77 57 50 56 59 90 70 71 91 80 78 39 51 54 56 38

L2

Syntax

91 61 65 63 90 73 61 66 67 97 74 81 91 93 89 59 55 67 68 30

L1 95 66 68 68 92 68 60 72 69 92 74 81 87 88 88 51 53 76 72 49

L2

Lexicon

93 42 47 50 82 76 53 57 60 96 74 77 100 100 88 62 53 73 65 12

L1

87 55 42 71 92 50 55 77 60 95 74 77 95 82 73 55 53 87 77 26

L2

Semantics

86 57 51 57 87 69 54 47 64 92 71 80 94 93 88 56 45 55 56 25

L1

88 59 63 62 86 67 50 66 56 89 72 77 87 80** 78** 40*** 41** 64** 65** 42*

L2

Total

Note. S ⫽ sex; A ⫽ age; Edu ⫽ years of education; TL ⫽ type of lesion (tumor, infarction, hemorrhage); LS ⫽ lesion site (F: frontal lobe; T: temporal lobe; P: parietal lobe; BG: basal ganglia; Th: thalamus; Ins: insula); Ass ⫽ interval between the onset of the lesion and language assessment; Aphasic Syndrome (B: Broca’s aphasia; W: Wernicke’s aphasia; G: global aphasia; A: anomic aphasia; TM: transcortical motor aphasia; TS: Transcortical Sensory Aphasia). Bold entries are related to the language that showed a significantly better recovery. * p ⫽ 0.7. ** p ⬍ .05. *** p ⬍ .01.

(KB) (CB) (EM) (OR) (PB) (DC) (AT) (DD) (FV) (ATM) (OM) (AS) (CM) (LM) (LT) (LV) (AM) (RT) (VD) (AL)

S

Subjects

Aphasic Sy

Phonology

TABLE 1 Linguistic Levels (Percentages of Correct Answers)

206 FRANCO FABBRO

207

BILINGUAL APHASIA

ent in different languages. Grammatical disorders observed in aphasics speaking different languages are such only at the surface level, but their nature seems to have a universal character and follow the rule whereby aphasia impairs all grammatical aspects of a language, even if at varying degrees of severity. The study of bilingual aphasics with parallel impairment of both languages allows us to confirm the hypothesis whereby grammatical disorders in aphasia depend on the language structure. Therefore, in ‘‘agrammatic’’ patients who know two morphology-rich languages such as Friulian and Italian grammatical errors will probably be similar in both languages and will be different only at the junctures where the two languages differ. With regard to the first four patients shown in Table 1 the percentage of morphosyntactic errors in obligatory contexts in L1 and L2 was calculated over a 5-min spontaneous speech sample (see Table 2). They all presented nonfluent aphasia with parallel recovery of the two languages. A comparison of errors made by patients in the two languages revealed that the most significant difference was the percentage of omissions of obligatory pronouns in Friulian (38.25%) vs Italian (1.25%). This is probably due to the peculiar grammatical structure of the two languages, as in Friulian the subject is always accompanied by an obligatory pronoun (Il frut al bef, literally: The boy he drinks), whereas in Italian the subject can be omitted (‘‘the child drinks’’ or ‘‘drinks’’). Therefore, in Italian aphasic patients can

TABLE 2 Percentage of Morphosyntactic Errors in Obligatory Contexts (during a 5-Min Sample of Spontaneous Speech) 1 (KB)

OFGM Articles Prepositions Conjunctions Obl. Pron. Aux. Verbs Full Verbs SBGM Verbs Adjectives Nouns SFGM Articles Prepositions Conjunctions Obl. Pron Aux. Verbs AGMIC Articles Prepositions Conjunctions Obl. Pron. Aux. Verbs

2 (CB)

3 (EM)

4 (OR)

L1

L2

L1

L2

L1

L2

L1

L2

4 — — 38 15 2

4 — — — — —

7 5 5 43 18 3

15 3 — 3 10 1

80 16 4 42 40 16

29 27 7 — 100 25

— 5 10 30 26 2

1 5 — 2 24 1

3 — —

1 1 —

5 7 2

3 2 —

— — —

— — 2

3 — —

11 — —

— — — 1 —

2 4 — 2 —

— — — 1 —

— — — — —

30 8 — — 13

4 27 — — —

— 1 — — —

3 7 — 2 —

— — — — —

2 — — 5 —

3 — — — —

— 6 — — —

— — — — —

— — — — —

3 3 2 — —

2 2 — — —

Note. OFMG ⫽ Omission of free grammatical morphemes; SBGM ⫽ Substitutions of bound grammatical morphemes; SFGM ⫽ Substitutions of free grammatical morphemes; AGMIC ⫽ Addition of grammatical morphemes in inappropriate contexts. Bold entries refer to the number of omissions of bound grammatical morphemes in L1.

208

FRANCO FABBRO

easily avoid structures requiring obligatory pronouns while in Friulian they cannot (Fabbro & Frau 2001). The analysis of morphosyntactic errors made by the first four patients with nonfluent aphasia confirms the hypothesis that the so-called agrammatism is—as suggested by Miceli and Mazzucchi (1990)—a theoretical construct and not a natural category. In both languages these patients made omissions of free-standing grammatical morphemes and substitutions of bound grammatical morphemes (errors that are reported to be typical of agrammatism), but also a small percentage of errors came from substitutions and additions of free grammatical morphemes, which are considered specific to paragrammatism. Rehabilitation of Bilingual Aphasics A consistent rehabilitation program for aphasic monolinguals and bilinguals requires a systematic assessment of language disorders. As far as rehabilitation programs for multilingual aphasics are concerned, several questions have been raised, many of which still need a satisfactory answer, namely (1) Is it enough to rehabilitate one language in bilingual aphasics or do all languages known by the patient have to be treated? (2) If the decision is taken to rehabilitate one language only, what are the criteria behind this choice? (3) Does rehabilitation in one language also have beneficial effects on the untreated languages? (4) Do potentially beneficial effects transfer to structurally similar languages (Italian and Spanish) only or also to structurally distant languages (Italian and Japanese)? (Paradis, 1993b). Unfortunately, research on language rehabilitation in bilingual aphasics is still at an early stage (cf. Fabbro, 1999b). So far researchers have mainly analyzed individual cases and, generally, they have not carried out a proper pre- and postrehabilitation assessment of language disorders. Indeed, very few research studies assessed the patients’ linguistic abilities before and after rehabilitation with a test equivalent in both languages. Conclusions drawn from these research studies are thus still speculative, and further studies are needed if more detailed information is to be acquired. At present, only one language is generally rehabilitated, especially if the patient shows mixing or switching phenomena, so as not to confuse the patient and waste time. Should two languages be simultaneously rehabilitated, sessions would increase from three to six per week; similarly six languages would require nine sessions, and so on. With regard to the selection criteria, no clear-cut answers are provided: Some researchers claim that the mother tongue is preferable, others claim that it is the least impaired language which should be treated, others, still, claim that the language that is worst impaired should be targeted. In the case of the bilingual aphasic patients I observed, selection of the language to be rehabilitated was based on two parameters: (a) a systematic assessment of the patient’s linguistic disorders through the BAT in the languages the patient knew and (b) an interview with the patient and his/her relatives was carried out during which neurolinguistic data were collected (neurological data, results of the BAT in the languages known by the patients, etc.) and sociolinguistic issues concerning the patient and his or her family were discussed (which language they preferred to rehabilitate both for affective and for business reasons). Therefore, except for highly complex neurolinguistic situations (for instance, aphasia with paradoxical recovery of one language), the choice of the language to rehabilitate depends on the patient and his or her family’s decision, since it was proven that generally the benefits of rehabilitation in one language tend to extend to the untreated languages (Fredman, 1975; Junque´, Vendrell, Vendrell-Brucet, & Toben˜a, 1989). This ‘‘mass effect’’ does not seem to be due to the degree of structural similarity

BILINGUAL APHASIA

209

between languages since it is effective not only in the case of structurally similar languages, but also with structurally different languages (Fabbro, De Luca, & Vorano, 1997). REFERENCES Aglioti, S., & Fabbro, F. (1993). Paradoxical selective recovery in a bilingual aphasic following subcortical lesions. NeuroReport, 4, 1359–1362. Albert, M. L., & Obler, L. K. (1978). The Bilingual Brain. New York: Academic Press. Alajouanine, T. (1963). L’aphasie et le langage pathologique. Paris: J. B. Baille`re. Alexander, M. P. (1989). Clinical-anatomical correlations of aphasia following predominantly subcortical lesions. In F. Boller & J. Grafman (Eds.), Handbook of neuropsychology (Vol. 2, pp. 47–66). Amsterdam: Elsevier. Bychowsky, Z. (1919/1983). Concerning the restitution of language loss subsequent to a cranial gunshot wound in a polyglot aphasic. In M. Paradis (Ed.), Readings on aphasia in bilinguals and polyglots (pp. 130–144). Montreal: Didier. Cappa, S. F. (1998). Spontaneous recovery from aphasia. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of neurolinguistics (pp. 536–547). San Diego: Academic Press. Chlenov, L. G. (1948/1983). On aphasia in polyglots. In M. Paradis (Ed.), Readings on aphasia in bilinguals and polyglots (pp. 445–454). Montreal: Didier. Fabbro, F. (1997). Bilingual aphasia research is not a tabula rasa. Aphasiology, 12, 138–141. Fabbro, F. (1999a). Aphasia in multilinguals. In F. Fabbro (Ed.), Concise encyclopedia of language pathology (pp. 335–340). Oxford: Pergamon Press. Fabbro, F. (1999b). The neurolinguistics of bilingualism. Hove, UK: Psychology Press. Fabbro, F., De Luca, G., & Vorano, L. (1996). Assessment of language rehabilitation with the BAT in four multilingual aphasics. Journal of the Israeli Speech, Hearing and Language Association, 19, 46–53. Fabbro, F., & Frau, G. (2001). Manifestations of aphasia in Friulian. Journal of Neurolinguistics, 14, 255–279. Fabbro, F., & Paradis, M. (1995). Differential impairments in four multilingual patients with subcortical lesions. In M. Paradis (Ed.), Aspects of bilingual aphasia (pp. 139–176). Oxford, UK: Pergamon Press. Francescato, G., & Salimbeni, F. (1976). Storia, lingua e societa` in Friuli. Udine: Casamassima. Fredman, M. (1976). The effect of therapy given in Hebrew on the home language of the bilingual or polyglot adult in Israel. British Journal of Disorders of Communication, 10, 61–69. Green, D. (1986). Control, activation, and resource: A framework and a model for the control of speech in bilinguals. Brain and Language, 27, 210–223. Grosjean, F. (1982). Life with two languages. An introduction to bilingualism. Cambridge, MA: Harvard Univ. Press. Grosjean, F. (1989). Neurolinguists, beware! The bilingual is not two monolinguals in one person. Brain and Language, 36, 3–15. Grosjean, F. (1994). Individual bilingualism. In R. E. Asher (Ed.), The encyclopaedia of language and linguistics (pp. 1656–1660). Oxford, UK: Pergamon Press. Grosjean, F. (1998). Studying bilinguals: Methodological and conceptual issues. Bilingualism, Language and Cognition, 1, 131–149. Junque´, C., Vendrell, P., & Vendrell, J. (1995). Differential impairments and specific phenomena in 50 Catalan-Spanish bilingual aphasic patients. In M. Paradis (Ed.), Aspects of bilingual aphasia (pp. 177–210). Oxford, UK: Pergamon Press. Luzzati, C., Willmes, K., & De Bleser, R. (1992). Aachener Aphasie-Test, Versione Italiana. Firenze: Organizzazioni Speciali. Nilipour, R., & Ashayeri, H. (1989). Alternating antagonism between two languages with successive recovery of a third in a trilingual aphasic patient. Brain and Language, 36, 23–48. Ojemann, G. A., & Whitaker, H. A. (1978). The bilingual brain. Archives of Neurology, 35, 409–412. Paradis, M. (1977). Bilingualism and aphasia. In H. Whitaker & H. A. Whitaker (Eds.), Studies in neurolinguistics (Vol. 3, pp. 65–121). New York: Academic Press.

210

FRANCO FABBRO

Paradis, M. (Ed.) (1983). Readings on aphasia in bilinguals and polyglots. Montreal: Didier. Paradis, M. (1988). Recent developments in the study of agrammatism: Their import for the assessment of bilingual aphasia. Journal of Neurolinguistics, 3, 127–160. Paradis, M. (1993a). Linguistic, psycholinguistic, and neurolinguistic aspects of ‘interference’ in bilingual speakers: The activation threshold hypothesis. International Journal of Psycholinguistics, 9, 133–145. Paradis, M. (1993b). Bilingual aphasia rehabilitation. In M. Paradis (Ed.), Foundations of aphasia rehabilitation (pp. 413–419). Oxford, UK: Pergamon Press. Paradis, M. (1994). Neurolinguistic aspects of implicit and explicit memory: Implications for bilingualism and SLA. In N. Ellis (Ed.), Implicit and explicit language learning (pp. 393–419). London: Academic Press. Paradis, M. (1995). Introduction: The need for distinctions. In M. Paradis (Ed.), Aspects of bilingual aphasia (pp. 1–9). Oxford, UK: Pergamon Press. Paradis, M. (1998). Language and communication in multilinguals. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of neurolinguistics (pp. 418–431). San Diego: Academic Press. Paradis, M. (2001a). (in press). Assessing bilingual aphasia. In B. Uzzell & A. Ardila (Eds.), Handbook of cross-cultural neuropsychology. Mahwah, NJ: Erlbaum. Paradis, M. (2001b). Bilingual and polyglot aphasia. In R. S. Berndt (Ed.), Handbook of neuropsychology (2nd ed.) (pp. 69–91). Oxford, UK: Elsevier Science. Paradis, M., & Canzanella, A. (1989). Test per l’afasia in un bilingue, Italian Version. Hillsdale, NJ: Erlbaum. Paradis, M., & Fabbro, F. (1993). Test pe afasie in t’un bilenghist, Friulian Version. Hillsdale, NJ: Erlbaum. Paradis, M., & Libben, G. (1987). The assessment of bilingual aphasia. Hillsdale, NJ: Erlbaum. Paradis, M., & Libben, G. (1999). Valutazione dell’afasia bilingue. Bologna: EMS. Paradis, M., & Goldblum, M. C. (1989). Selective crossed aphasia in a trilingual aphasic patient followed by reciprocal antagonism. Brain and Language, 36, 62–75. Paradis, M., Goldblum, M. C., & Abidi, R. (1982). Alternate antagonism with paradoxical translation behavior in two bilingual aphasic patients. Brain and Language, 15, 55–69. Paradis, M., & Gopnik, M. (1997). Compensatory strategies in genetic dysphasia: Declarative memory. Journal of Neurolinguistics, 10, 173–186. Pitres, A. (1895). Aphasia in polyglots. In M. Paradis (Ed.), Readings on aphasia in bilinguals and polyglots (pp. 26–49). Montreal: Didier. Pinker, S. (1994). The language instinct. London: Penguin Books. Silverberg, R., & Gordon, H. W. (1979). Differential aphasia in two bilingual individuals. Neurology, 29, 51–55. Spinnler, H., & Tognoni, G. (1987). Standardizzazione e taratura italiana di test neuropsicologici. The Italian Journal of Neurological Sciences, Suppl. 8, 5–120. Yiu, E. M., & Worrall, L. E. (1996). Sentence production ability of a bilingual Cantonese–English agrammatic speaker. Aphasiology, 10, 505–522.