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.I. Neurolmgursrics, Volume 3. Number 2, Prmted in Great Britain pp. 161-183, 1988. 0 091 f-6044/88 $3.00 + .OO 1988 Pergamon Press plc Assigning Linguistic Roles: Sentence Interpretation in Normal and Aphasic Kannada-English Bilinguals Jyotsna Shyamala Vaid Department of Psychoiogq Texas A & M University Chengappa Department of Speech Pathology All India Institute of Speech and Hearing ABSTRACT In interpreting a sentence, listeners rely on a variety of linguistic cues to assign grammatical roles such as agent and patient. In normal sentence comprehension these cues converge to enable sentence interpretation, yet when the cues are placed in competttion they are differentially used by speakers. The present study investigated the relative strength of three cues to agenthood - word order, noun animacy and subject-verb agreement - in normal and aphasic Kannada-English bilinguals and Kannada monolingual controls. The findings are discussed with respect to other crosslinguistic evidence using the sentence interpretation paradigm and with respect to their bearing on theories of bilingual language representation. In interpreting a sentence we rely on a variety of surface linguistic cues ranging from phonological stress, morphological markers and syntactic-semantic cues such as word order and noun animacy. The information conveyed by these cues allows us to identify the topic of a sentence, to distinguish between given and new information and to assign grammatical roles. In acquiring a first or a second language, a language user must learn what kinds of information are conveyed by particular linguistic cues present in the surface form. The mapping between form and function is rarely one-to-one for a single form can map to several functions and several forms can map to the same function. For example, in English, cues such as word order, pronoun case inflection and noun animacy all convey information about grammatical roles. Although more than one 162 Journal of Neurolinguistics, cue conveys information Volume 3, Number 2 (1988) relevant to the same comprehension in how well they convey this information. The accuracy process, the cues vary with which a cue conveys information is known as its validit),. Cue validity may be viewed as the product ofa cue’s availability and reliability. Availability is a measure of how often a cue is present, reliability is a measure of how often a cue points to the correct interpretation when it is present. Cue validity can be calculated from adult language input to the language learner (cf. McDonald 1984). While overall cue validity predicts order of acquisition, conflict validity (see McDonald 1987) predicts order of adult strength of usage. COMPETITION MODEL The concept of cue validity has been incorporated into a model of sentence comprehension developed by Bates and MacWhinney (1982. 1987). This model, known as the Competition Model. offers a probabilistic account of how cues combine during comprehension. ln this model. each cue is accorded a strength or weighting proportional to its validity. This weighting in turn determines the amount of activation of a particular interpretation. If two cues agree as to an interpretation, their strengths are added, leading to a greater activation of that interpretation compared to when a single cue is present. If they disagree. the interpretation with the highest activation level is chosen. In this way, cues are thought to cooperate and compete in the comprehension process. SENTENCE INTERPRETATION The notion of cue validity been empirically examined PARADIGM and its psychological by MacWhinney counterpart cue strength et al. (1984) in cross-linguistic has studies of sentence processing. The basic paradigm in this research involves a sentence interpretation task where native speakers of different languages are presented with simple, transitive sentences containing two concrete nouns and a concrete action verb and are asked to identify the agent - that is, who performed the action described in the sentence. While in normal discourse various cues arecorrelated, in the sentence interpretation paradigm the sentences always represent orthogonal combinations of lexical-semantic, pragmatic, grammatical and/ or phonological cues, thereby allowing for an independent examination of the relative contribution of each of these types of information. The result of selecting sentences in this way is that a number of semi-grammatical sentences are included along with grammatical sentences. Nevertheless. their syntactic or semantic oddness does not appear to affect how they are processed as previous research with this paradigm has shown. Bilingual Sentence Interpretation For example, the obligatory Hungarian speakers case markings comprehend ungrammatical have been deleted sentences 163 in which in the same way in which they process grammatical sentences where the omission of this case marking is allowable (MacWhinney et al. 1985). In some of the sentences in this task the various cues converge to a single decision about who did the action while in other sentences one or all of the cues may conflict. An example where the cues of word order, subject-verb agreement and noun animacy conflict is in the sentence “The dog lick the pencils”. Standard subject- verb ~ object (SVO) word order in English would assign the preverbal noun dog as actor as would the animacy cue, but noun-verb agreement would favor the plural noun pencils, which agrees in number with the plural verb form. In such cases native speakers of English rely most on word order, discardingpencils as the actor despite the agreement cue. Italian speakers, however, tend to choosepencils as the agent, for agreement cues are stronger than word order cues in Italian. For German speakers, animacy and agreement turn out to be stronger cues than word order and for Hungarian and Serbo-Croation speakers case is a stronger cue than word order. In short, adult native speakers interpret sentences by making preferential use of the cue that is the most valid (or informative) in their language. Thus, the relative ranking of cues may often differ across different languages, even when the languages on a formal level are typologically similar (e.g. Italian and English). Developmental studies using the sentence interpretation paradigm to study children as young as two years of age indicate that cue validity based on adult usage is a strong predictor of the developmental sequence of acquisition of the cues. Word order (SVO) is the first cue to emerge in English-speaking children and nominative/accusative case marking is the first to emerge in Turkish children (Bates and MacWhinney 1987). Within the Competition Model framework, lan- guage learning is viewed as a process of incrementing and adjusting the weights of form-function mappings until there is an optimal fit with the processing environment (MacWhinney 1987). STUDIES WITH BRAIN-INJURED INDIVIDUALS Given that there are differences in how normal listeners monitor different cues in the input, one might expect differences in cue validity to be reflected in the pattern of language impairment of brain-damaged individuals. In fact, language-specific differences in cue strength appear to be preserved in aphasics (see Bates et al. 1987). In general, the cue that has the highest strength in premorbid language use appears to be the most resistant to impairment following brain damage. At the same time, there appears to be a global impairment of certain cues (e.g. subject-verb agreement) regardless of their premorbid status in a particular language, and a selective 164 Journal of Neurolinguistics, sparing aphasics of other cues. e.g. word using the sentence SENTENCE A recent Volume 3, Number 2 (1988) INTERPRETATION extension order interpretation (see Bates et al. in press). paradigm Research on is still in its infancy. IN BILINGUALS of the sentence interpretation paradigm has involv,ed a comparison of sentence interpretation strategies used by bilinguals or second language learners in their two languages. This topic has thus far been addressed in users of predominantly Indo-European languages including Spanish (Wulfeck 6’1 al. 1986) and German (Bates and MacWhinney 1981: McDonald 1984). but a few other language families are also being studied. typically with English being one of the two languages under study. These other languages include Dutch(Kilborn 1986: Kilborn and Cooreman 1987). Korean (Park 1986), Japanese (Kilborn and Ito 1987) and Hindi (Vaid et (11. 1987). On a theoretical level. the sentence interpretation task in bilinguals 15of interest in that it allows a test of different hypothesized views about bilingual language representation. Most previous work in this area has concentrated on the lexical level, typically using lists of unrelated words. The sentence interpretation task allows for an examination of higher-level language comprehension strategies in each language. POSSIBLE OUTCOMES IN BILINGLIALS A priori. one can distinguish between four different possible outcomes on the task, reflecting different forms of internal representation of bilingual discourse. Assuming language-specific differences on the task (as reflected in different strategies used by monolingual speakers of the different languages). one possible outcome for bilinguals on this task may be a transfer of first language strategies to the second language. This outcome would be expected for individuals at early stages of second language exposure and/or proficiency and would support a “subordinate” form of bilingual language organization. where the first language cues remain dominant and the second language is processed in terms of cues that are salient in the first language (see McDonald 1987). A second possible outcome is one in which the bilingual shows a different pattern in each language, corresponding to the ranking of cues of monolingual speakers of the respective languages This kind of response would support a”coordinate” form of representation where distinct sentence comprehension strategies are used for the two languages. A third possible outcome is where bilinguals show a unified strategy in each 01 their languages. but this strategy differs from that used by monolingual speakers of the Bilingual Sentence Interpretation languages and represents of the languages. an amalgam Such an outcome or merger of cues that are dominant would be consistent with a “compound” 165 in each form of representation (see Wulfeck et al. 1986). Finally, it is possible that bilinguals may show a reverse subordinate pattern such that their performance on their second language is comparable to that of monolingual speakers of that language and their performance on their native language is influenced by their second language. Such an outcome might be expected to arise if the bilinguals are more practised in their second language than in their first. These four hypothesized outcomes are not mutually exclusive nor are they rigid over time. Rather, at different stages of a bilingual’s language history, different outcomes may be observed. For example, McDonald (1984) found that L2 speakers with little exposure to the second language use Ll strengths; with increasing L2 exposure the L2 speakers shift to appropriate L2 weights. means of classification. The outcomes should thus be viewed merely as a useful In what follows, sentence interpretation data are presented from adult bilingual speakers of Kannada and English. A language from the Dravidian language family used primarily in south India, Kannada is spoken by over five million speakers. Sentence interpretation data are presented from a group of brain-intact Kannada monolingual adults and Kannada-English bilinguals and from a smaller group of aphasic counterparts. To date there has been only one published study of sentence interpretation in bilingual aphasics (Wulfeck ef al. 1986). RELEVANT CHARACTERISTICS OF KANNADA GRAMMAR Some remarks are in order at this point about the characteristics of Kannada of relevance to the sentence interpretation task. First. Kannada is a case-marked language. The case system of Kannada is similar to that of other Dravidian languages in that various suffixes are added to the noun stem to indicate different relationships between the noun and the other sentence constituents. The cases include the nominative, genitive, dative, locative, instrumental; ablative, vocative and accusative (Schiffman 1979). The basic colloquial accusative marker is - anna/ - annu. It is used with both “rational” (capable of thought) and “non-rational” referents (usually animals, young children and inanimate objects). It is also possible for the accusative markers to be omitted entirely except in the case of rational (masculine and feminme) nouns. Case markers used with plural nouns are usually the same as those used with the singular, but often in colloquial Kannada the plural marker -galu is not used, 50 the singular can be found even when more than one object is meant. In previous sentence interpretation studies performed on other case-marked languages (e.g. Serbo-Croation), case has emerged as a dominant cue. It is likely to play a strong NEL 3:2-D 166 Journal of Neurolinguistics, role in Kannada sentence Volume 3, Number 2 (1988) interpretation as well. Since our interest was In com- paring Kannada and English on cues that both languages possess to a comparable degree, it was decided to delete the accusative case marker from the Kannada stimuli so as to render the task of interpretation at least as ambiguous as that in English. The cues chosen for study in the two languages. then. were noun animac!;. noun-verb agreement and word order. Word order may perhaps be a weaker cue in Kannada than in English since Kannada permits more variation in word order, given that linguistic roles are normally signalled by case markers. Moreover, Kannada uses a subject-object verb (SOV) word order. VSO or VOS word orders are stylistic variations referred to as “after thought” word orders used in colloquial speech (Schiffman 1979). The nature of the word order effect might be expected to differ in Kannada and English. a SVO language. The subject in Kannada sentences agrees with the verb in number and gender. We would thus expect the agreement cue to be at least as strong as that in English and perhaps stronger since non-verb agreement in English is only on the basl5 of number. There is no a priori basis for expecting a difference in the strength of the animacy cue in the two languages. In neither language IS noun ammacy overtI>, marked; rather it 1s one of the semantic properties associated with a noun. STUDY I Sentence Interpretation In order to understand in Brain-intact Kannada-English Kannada Speakers bilinguals performance on the sentence interpretation task, it is important to understand the cues used by monolingual Kannada speakers. Thus both groups were tested. Method Subjects Subjects included a group of 8 Kannada monolinguals and 21 Kannada-Enghsh bilinguals. All were right-handed. The monolingual sample included 2 males and 6 females ranging in age from 21 to 60 years with a mean age of 40 years. The bilingual sample ranged in age from 20 to 62 years with a mean age of 3 1 years and included 6 females and 15 males. The bilinguals’ mother tongue was Kannada in all cases. They had studied English in school until their second year of college and had been enrolled in English-medium schools throughout their education. Many subjects also received post-graduate training in English. As such, the sample was highly fluent in English. A brief questionnaire administered to the bilinguals revealed that the majority of Bilingual Sentence Interpretation subjects newspaper reported using and writing English letters; at work Kannada and with friends was used primarily 161 and in reading the at home and with friends. Stimuli For each language, a total of 54 sentences were constructed. The stimuli were all simple, active, declarative sentences with two concrete nouns and a transitive action verb. All three word orders (NVN, VNN and NNV) were tested in orthogonal combinations of noun animacy (both nouns are animate, yielding semanticallyreversible sentences; only the first noun is animate; only the second noun is animate) and noun-verb agreement (the verb agrees with both nouns in number; the verb agrees only with the first noun; the verb agrees only with the second noun). The 3 X 3 X 3 factorial design resulted in a total of 27 sentences. Two examples of each sentence type were included, yielding a total of 54 sentences. To minimize the effect of extralinguistic, real world knowledge on sentence comprehension, the stimuli were prepared using a random assignment of animate and inanimate nouns to the designated slots in the sentences. While the Kannada and English sentences were not translation equivalents, they were constructed from the same pool of words. The set of nouns and verbs used to generate the stimuli in each language is provided in the Appendix. Procedure Subjects were all tested individually. The sentences were read out loud one at a time in a neutral intonation by the examiner (SC) who is a native speaker of Kannada and fluent in English. Upon hearing each sentence, subjects were to indicate which of the two nouns - the first or the second - had performed the action described in the sentence. Practice trials were given to ensure that subjects understood the task. The order of testing for the bilinguals was alternated across subjects such that half were tested in Kannada first followed by English while the remainder were first tested in English. A gap of at least a day separated the two testing sessions. Scoring If the first preverbal noun mentioned was chosen as the actor, subjects received a score of 1. Choice of the second noun was assigned a score of0. Since there were two sentences with each possible combination of the three factors, the maximum score possible was 2, indicating that subjects chose the first noun both times for that sentence type. The dependent variable was the percentage choice of the first noun as agent. Chance performance would be designated by 50%; 100% would indicate a choice of the first noun on every item and 0% a choice of the second noun. 168 Journal of Neurolinguistics, Volume 3, Number 2 (1988) Results Analyses of variance were performed on the percentage of lirst preverbal nouns chosen as the agent for each sentence type. The monolingual data were analyzed first tn a separate analysis of vartance and were subsequently compared with the bilinguals’ Kannada data tn a combined analysts of vartancc. The bilinguals’ data were further analyzed to compare performance tn their two languages. Kannada Monolinguals Mean scores ranging from 0 to 2 on the sentence interpretation test were entered into a 3 X 3 X 3 analysis of variance as a function of noun animacy, word order and verb agreement. There were two significant effects: a main effect of animacy (pc .OOOl) and an animacy X agreement interaction (pc .OOl). The animacy effect accounted for 84c7, of the variance while the two-way interaction accounted for an additional 8qc of the vartance. Table I summarizes the ANOVA results for the monolinguals. Table I Summary of ANOVA of Kannada Normal Monolinguals (n=8) Source df F P Animacy Agreement Word order 2, 14 2, 14 2. 14 80.63 3.12 0.14 ,000 1* ,076 ns ,672 ns Animacy Animacy 4, 28 4, 28 5.97 0.85 .001* .507 ns 4. 28 8. 56 0.94 0.79 456 ns ,612 ns X agreement X order Agreement X order Animacy X agreement X order * Significant ns, not significant The main effect of animacy indicated that the percentage choice of the first noun as agent was much higher when the first noun m the sentence was animate and the second noun was inanimate (88Yc) than when both nouns were animate (6357’) or only the second noun was animate (254). The interaction of animacy and agreement revealed that verb agreement was used as a cue only when animacy cues were neutral or absent. as when both nouns in the sentence are animate. In this condition, the percentage choice of the first noun was 794% when the first noun agreed in number with the verb, whereas tt fell to 40 c?cwhen the second noun agreed Bilingual Sentence Interpretation with the verb. With animacy diminished noun cues present, the agreement as in the animate-inanimate condition choice in the first-noun-agreement 169 effect was either greatly (compare 94% vs. 81% first- and second-noun-agreement conditions, respectively) or was completely absent, as in the inanimate-animate condition (where the percentage choice of first noun remained a low 29% for first-noun and second-noun-agreement conditions). The word order effect was not significant in Kannada: subjects showed a consistent preference of the first noun (around 6OYo) for all three word orders. Figure 1 illustrates the performance of the Kannada monolinguals relative to that of English monolinguals tested in previous studies by Bates and colleagues. Note that while the agreement effect is weak in both language groups, the animacy effect is particularly strong in Kannada relative to English while the reverse is true for the word order effect. I 0 Kannado A English ‘71 I \ \ d’ 1 \ I 4 I NVN Word VNN I \ I b I I NNV order An ~macy Agreement Monolinguals Figure 1. Kannada vs. English Monolinguals: Animacy and Agreement. Kannada Monolinguals A 2 X 3 X 3 X 3 factorial vs. Kannada-English analysis of variance Main Effects of Word Order, Bilinguals was performed on Kannada on the Kannada data 170 Journal of Neurolinguistics, Volume 3, Number 2 (1988) of monolinguals and bilinguals. All three within-subject variables (animacy, agreement and word order) were highly significant, as were two two-way mteractions: animacy X agreement (p < .OOOl) and animacyX word order(p .:: .002). It is noteworthy that there were no significant bilingual/monolingual group differences nor were there any significant interactions involving the group variable. Kannada-English A four-way Bilinguals analysis on Kannada vs. English of variance (animacy by agreement by word order by language) was performed on the bilinguals’data to compare their performance on their two languages. A summary of the ANOVA results is presented in Table 2. The analysis indicated significant main effects of animacy, agreement and word order as well as 2 two-way interactions: animacy X agreement (p c: .0009) and Table 2 Summary of ANOVA for Kannada-English Normal Bilinguals (n = 21) Source Animacy Agreement Word order Language Animacy X agreement Animacy X order Agreement X order Animacy X language Agreement X language Order X language Animacy X agreement X language Animacy X order X language Agreement X order X language Animacy X agreement X order Animacy X agreement X order X language * Significant ns. not significant df F P 2.40 2.40 2,40 1,20 4,80 4,80 168.95 16.65 8.55 1.63 5.19 6.76 4.80 2,40 2.40 2.40 4,80 0.31 0.53 0.53 1.04 4.80 1.38 3.04 3.26 1.81 .0001* .0001* .0008* .22 ns .0009* .0001* .87 ns 4,80 4,80 8,160 8.160 .59 ns .59 ns .36 ns .002* .25 ns .02* .002* .08 ns Bilingual Sentence Interpretation animacy X order (p < .OOOl). In addition, 171 there were three higher order interactions: animacy X agreement X order (p < .002) and language X animacy X agreement (p < .02). Figure 2 illustrates the three main effects in each language. The main effect of animacy accounted for the greatest proportion of the variance (82%), while the main effect of agreement accounted for 8% and the interaction effects together constituted about 1070 of the variance. o Kannada A English 80 Iu ; 0 5 fro- ‘tB, e --Cl ‘1 .E E 40- 20 - 0 I NVN I VNN Word I NNL I AA order I I I Al IA NJ0 Anrnacy Normal bilinguab Figure 2. Kannada-English Agreement Bilinguals: I Agl I Ag2 Agreement ( n = 2 I) Effects of Word Order, Animacy and by Language. Let us examine the two higher-order interaction effects involving language. The means for the language X animacy X agreement effect are summarized in Table 3. Note first that in both Kannada and English the presence of an animate first noun greatly increases the percentage choice of the first noun as agent while the presence of an inanimate first noun greatly reduces it. When animacy cues are absent (when both nouns in the sentence are animate) the choice of agent is governed by agreement cues. These cues appear to be stronger for Kannada than for English. 172 Journal of Neurolinguistics, Volume 3, Number 2 (1988) Table 3 Kannada-English Normal Bilinguals (n = 21): Language X Animacy X Agreement Interaction Means (in %) English Kannada AA Al IA AgO f%l AS AgO Agl AS 72 88 8 86 93 24 47 78 12 59 80 16 68 87 36 53 66 20 The other interaction effect was language X agreement X word order. Table 4 provides a summary of the interaction means. Inspection of the table suggests that the source of the interaction hes in the NNV condition: when agreement is with the ftrst noun in this word order condition, the percentage choice of the ftrst noun 1s much higher in Kannada (7O?e) than it is in English(56qe). The analogous effect for NVN word order does not appear to be present. that is, the percentage choice of the first noun is only marginally higher in English than in Kannada (74$$ vs. 68%)) when agreement is with the first noun in the NVN condition. Table 4 Kannada-English Normal Bilinguals (n = 21): Language X Word Order X Agreement Interaction Means (in %) English Kannada AgO NVN VNN NNV 61 53 54 Ad A@ 68 65 70 55 44 40 AgO Ad 49 60 48 47 74 60 56 52 46 42 Bilingual Sentence Interpretation 173 Discussion It would appear that animacy is the cue with the greatest cue strength in Kannada at least among the cues tested, since case would presumably have been a strong cue in Kannada as well. In monolinguals and bilinguals alike, the animacy main effect accounted for by far the largest proportion of the variance. The cue used next appears to be verb agreement, although its effect is evident only in the absence of animacy cues. The weakest cue seems to be word order. The performance of bilinguals on Kannada was indistinguishable from that of Kannada monolinguals. While this finding may not be all that surprising given that Kannada was the first language of the bilinguals, it is nevertheless interesting that the bilinguals were not in any way influenced by their exposure to English, despite their apparently high level of proficiency in English. As such, the present study does not support hypothesized outcome 4 stated at the outset. One can speculate that the word order cue was not used by Kannada-English bilinguals when processing English because the English spoken in India has different structural properties than the English spoken in America. While there may be some basis for this speculation it should be pointed out that HindiiEnglish bilingual speakers do rely on word order when processing English (see Vaid et al. 1987). Thus the observed lack of reliance on word order in Kannada speakers would appear to suggest a languagespecific influence of Kannada, rather than sociolinguistic differences in the nature of English used in India. When we consider the bilinguals’ performance noteworthy that across both languages animacy on Kannada vs. English, it is again accounted for the most variance (over 80%). Word order was a relatively weak cue, even in English. In the two instances where language differences were significant, the nature of the difference was such that the effect (of agreement in one case and of word order in another) was more pronounced in Kannada than in English. Specifically with regard to the word order effect, while NVN sentences yielded a slight first-noun preference in both Kannada and English, NNV sentences yielded a strong firstnoun preference in Kannada as compared to that in English. This difference reflects the different structural properties of the two languages, inasmuch as Kannada is a SOV language whereas the typical response of native English speakers to the noncanomcal NNV word order is to choose the second noun as agent (see MacWhinney et al. 1984). Thus, it would appear that the response of the bilinguals on this task supports the first of the four hypothesized outcomes, namely, a transfer of first language strategies onto the second language. The results do not support a situation where bilinguals show a particular ranking of cues in one language and another ranking in the other language. Rather, their performance on Kannada is almost identical to 174 Journal of Neurolinguistics. Volume 3, Number 2 (1988) that of Kannada monolinguals. version of their Kannada-based while their performance on English is a muted strategy and in no way resembles the performance of English-speaking monolinguals. This outcome is somewhat surprising given the high degree of English language proficiency reported by the bilinguals. The present results suggest, therefore. that the sentence interpretation strategies observed need not be related in any obvious way to the individual’s level of proficiency. Alternatively, it may be that. at the level of discourse processing, proficiency may mean something different. STUDY Sentence 2 Interpretation in Aphasic In this section of the paper, interpretation task administered Kannada-speaking adults. Kannada Speakers we summarize the findings from the sentence to a group of left-hemisphere damaged native Method Subjects Two monolingual Kannada aphasics, S.A. and B.B., were tested at the National Institute of Mental Health and Neurological Sciences (NIMHANS) in Bangalore. Both were patients at the Speech Pathology unit at NIMHANS where, on the basrs of a standard aphasia test battery adapted to Kannada. they were diagnosed as being receptive aphasics. In addition, three Kannada-English aphasic bihnguals who were also patients at NIMHANS were tested. Two of these patients( K. K. and J. P.) had been diagnosed as expressive aphasics and the third (N.D.) was a receptive aphasic. While it was not possible to obtain a detailed premorbid language use inventory on the bilingual patients, a brief interview with the patients’ immediate family confirmed that the bilingual patients’ language background and premorbid language use was not all that different from that reported for the bilingual controls in Study 1. Criteria used to exclude patients from participation in this study included the following: (a) a history of multiple strokes; (b) significant hearing and/or visual deficits; (c) severe gross motor disabilities; (d) severe motor speech involvements such that speech was all but unintelligible; and (e) evidence of neurological instability and/ or testing less than 3 months post-onset of insult. Monolingual Aphasics Both monolingual patients S. A. and B. B. spoke Kannada as a mother tongue and had Kannada as the medium of instruction m school through graduation S.A. had suffered a post-traumatic cerebral contusion and an acute subdural Bilingual Sentence Interpretation hematoma in the left temporal lobe following a traffic accident. 175 On the basis of a Kannada adaptation of the Western Aphasia Battery, S.A. was diagnosed as having Wernicke’s asphasia. S,A.‘s language functions were tested 15 days postinsult. At the time of testing, S.A. had a mild hemiparesis and aphasic symptoms. B.B. was diagnosed on the basis of a CT scan as having had an infarct in the left temporoparietal region. His language functions were tested four months postinsult using the Western Aphasia Battery and, like S.A., he was also classified as a Wernicke’s aphasic. At the time of testing one and a half years post-insult, B.B. had almost recovered from a right hemiparesis but still had aphasic symptoms. Bilingual Aphasics All three bilingual aphasics. J.P., K.K. and N.D., had studied Kannada and English in school as their first and second language, respectively. From grade 10, all three had English as the medium of instruction and used English in their work. The etiology of J.P.‘s brain injury, as indicated by a CT scan, was a left cervical internal carotid aneurysm with cerebral embolism. The other two patients were not Table 5 Background Subjects’ initials type K mono B.B. K mono Group Information Aphasia on Kannada Aphasics Sex Age Hand dom. Etiology Receptive M 37 R Left internal carotid insufficiency. Right hemiparesis 1.5 years earlier S.A. Receptive M 27 R Left temporal lobe problems due to left subdural hematoma K-E bi N.D. Receptive M 3s R Left internal insufficiency carotid K-E bi K.K. Expressive M 56 R Left internal insufficiency carotid K-E bi J.P. Expressive M 30 R Left internal insufficiency carotid 176 Journal of Neurolinguistics, Volume 3, Number 2 (1988) advised to have a CT scan done and were diagnosed simply as having a left carotid insufficiency, that is, inadequate blood supply to the cortical lobes by the middle cerebral artery, perhaps as a result of a thrombosis or embolism. All three patients had hemiplegia with aphasia. N.D. had almost recovered from the hemiplegia at the time of testing. Language testing of K.K. was done three months after the cerebral insult, one month post-insult for J.P. and two years post-insult for N.D. Table 5 provides a summary of the background characteristics of the patients. Stimuli and Procedure The same set of sentences used in Study 1 were administered to the braindamaged subjects. Sentences were read aloud to the patients by the same examiner who had tested the normal subjects. Patients signalled their responses by pointing to the appropriate noun on the stimulus sheet. Sufficient practice trials were given to ensure that the patients understood the task. Bilinguals were tested in therr two languages in separate sessions, with the order of the sessions being varred across subjects. The data were coded as in Study I with the additional feature that a score of 5 was assigned on any trial on which subjects failed to make a response. Table 6 Performance of Kannada-English Bilingual Aphasics (Percentage Choice of First Noun) Animacy AA AI IA 84 72 61 44 72 16 Agreement AgO AgJ Ag2 61 84 72 56 28 50 Word order NVN VNN NNV 72 61 84 34 44 56 Bilingual Sentence Interpretation 177 Results Monolingual Aphasics Given the small sample size, an analysis of variance was not conducted. the data from the two monolingual aphasics are individually summarized Instead, in Table 6. Inspection of the mean percentage choice of first-noun scores suggests that the animacy cue was used by both subjects and was particularly dominant for B.B. When the first noun of the sentence was animate. B. B. chose the first noun as agent 72% of the time as compared to 16% of the time when the first noun was inanimate. Animacy may have been the only cue utilized systematically by B. B. inasmuch as his performance on the other two factors appears to be essentially random. S. A., on the other hand, showed some sensitivity to verb agreement, choosing the first noun as agent 84% of the time when that noun agreed with the verb, as compared to 61% of the time when agreement was ambiguous. S. A. also appeared to favor a first-noun preference for sentences with the order NNV (84%) and to a lesser extent for NVN sentences (72%). Bilingual Aphasics on Kannada vs. English Owing to the small sample size it was not advisable to conduct a statistical Table 7 Performance of Kannada-English Bilingual Aphasics (Percentage Choice of First Noun) Kannada N.D. Animacy Agreement K.K. AA 39 72 83 AI IA 83 0 100 6 89 39 AgO 61 33 39 56 67 56 83 67 61 50 67 61 50 67 67 78 Ag1 Ag2 Word order J.P. NVN VNN NNV 44 39 Con td. 178 Journal of Neurolinguistics, Volume 3. Number 2 (1988) Table 7 - Contd. English Animacy AA AI IA Agreement AgO Agl Ag2 Word order 61 44 89 11 100 17 39 61 50 NVN 44 VNN 56 61 NNV 61 50 89 11 50 50 56 50 44 56 50 50 44 50 56 analysis of the data. The data from the three bilingual aphasics are therefore summarized in Table 7. In all three bilingual patients, the animacy cue appears to have been spared, in both Kannada and English. The percentage choice of the first noun was generally higher when the first noun was animate (the scores ranged from 83 to 100%) than when the first noun was inanimate (the scores ranged from 0 to 3996). By contrast, the agreement cue appears to be largely unavailable in either language. for none of the subjects showed a clear main effect of agreement. Had there been more subjects, it would have been possible to examine whether the agreement cue is in fact present under certain conditions of the other two factors. Similarly, word order does not appear to have been a salient cue for the bilingual aphasics. particularly in English, where performance was essentially at chance level for all subjects. In Kannada, one subject (K. K.) showed a slight effect of word order, favoring a first-noun preference for NNV sentences (78”~). Discussion Given the small numbers of patients tested, any generalizations drawn from the aphasia data must be made with caution and should be viewed largely m terms of their heuristic value. Even with such a small sample size, certain trends were observed. For one thing, it would appear that semantic information, as reflected in the animacy variable, is clearly preserved in these aphasics. As such the present data are consistent with those reported for German aphasics (Bates et ul. 1987) who also Bilingual Sentence Interpretation showed a sparing that what should of animacy. This sparing of animacy be preserved in aphasia is consistent 179 with the notion are cues that were premorbidly the strongest cues in the language. As we have already seen in Study 1, animacy was in fact the strongest cue for Kannada speakers. There does not appear to be a sparing of grammatical morphology in the present sample of aphasics. This vulnerability of morphological cues is consistent with observations reported on native English-speaking and Italian aphasics (Bates et al. 1987). but does not appear to be restricted to aphasics, for it is found even among non-aphasic brain-damaged individuals (Bates et al. 1987). The theoretical significance of this finding remains to be determined. Finally, word order appears to have been partially spared in the present sample. One of the monolinguals (S. A.) and one of the bilinguals (K. K.) showed a firstnoun preference for NNV sentences in Kannada, consistent with the strategy observed in brain-intact monolingual and bilingual Kannada controls. This preference for the first noun as agent in sentences in which two nouns precede the verb reflects an SOV interpretation of this particular word order. It is noteworthy that, even in the absence of case markers, both brain-intact and brain-damaged individuals were sensitive to this statistical and structural property of Kannada. CONCLUSION The normative bilingual data (Study tation in which first language discourse 1) support a view of bilingual represenstrategies are mapped onto the second language. The fact that this particular outcome was observed in our subject sample despite the relative fluency and competence of our subjects in English is particularly interesting and contrasts with the pattern observed for a group of Hindi-English bilinguals (Vaid et al. 1987). In the aphasic bilingual group as well, when there was a sparing of cues, it was in favor of cues that are used in Kannada or, alternatively, the cue that is most dominant in Kannada (namely, animacy) was extended to English sentence interpretation as well, whereas the cue that is normally speakers (namely, word order) was relatively and normals alike. the strongest absent in Kannada cue in English speakers, aphasics 180 Journal of Neurolinguistics, Volume 3, Number 2 (1988) ACKNOWLEDGEMENTS This research was partially supported by a National Institute of Health Research Grant on cross-linguistic studies of aphasia awarded to Elizabeth Bates of the University of California, San Diego and by a Council for International Exchange of Scholars Indo-American Advanced Research Fellowship awarded to Jyotsna Vaid. We acknowledge with gratitude the Speech Pathology unit of the National Institute of Mental Health and Neurological Sciences in Bangalore. India, under whose auspices the data were collected. Tom Battocletti and Miguel Quinones of Texas A & M University assisted in data analysis. We thank Janet McDonald for her comments on the manuscript. Requests for reprints may be directed to the first author c/o Department of Psychology. Texas A & M University. College Station, TX 778434235, U.S.A. l&II Bilingual Sentence Interpretation REFERENCES Bates, E., A. Friederici, and B. Wulfeck 1987 “Comprehension in Aphasia: Language A Cross-linguistic Study,” Bruin and 32, 19-67. 1988 “On the Preservation of Word Order in Aphasia: Cross-linguistic Evidence,” Brain and Language 33, 323-364. “Grammatical Morphology in Aphasia: Evidence from Three Languages,” Correx (in press). Bates, E. and B. 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Bilingual Sentence Interpretation APPENDIX Pool of Sentence Animate Inanimate Verbs nouns nouns Interpretation Stimuli English Kannada Zebra Pig Elephant Bear Donkey cow Monkey Donkey Elephant Cat Donkey Block Rock Ball Pencil Stick Umbrella Ball Book Hitting Biting Smelling Patting Eating Kissing Pushing Grabbing Hitting Biting Touching Patting Eating Kicking Pushing Calling Licking Licking cow 183