Finiteness and verb-second in German agrammatism

This study presents results from sentence-completion and grammaticality-judgement tasks with seven German-speaking agrammatic aphasics and seven age-matched control subjects examining verb finiteness marking and verb-second (V2) placement. The patients were found to be selectively impaired in tense marking in the face of preserved mood and agreement marking. Moreover, our results revealed that V2 scores varied across our patients, with some showing impaired and others preserved V2 performance. These findings will be discussed in the light of different syntactic accounts of agrammatism.     

An Acoustic Analysis of Rate of Speech Effects on Vowel Production in Aphasia

The present investigation examined the production of tense and lax vowel duration differences at two speaking rates in the speech of 10 nonfluent aphasics, 8 fluent aphasics, and 10 normal control subjects. Subjects produced four repetitions of each of the vowels [i e æ o u I ε υ Λ] at each speaking rate. Acoustic analyses revealed that subjects in all three groups were able to manipulate overall rate of speech. In addition, normal controls and fluent aphasic subjects produced vowels under the fast rate condition which were significantly shorter than those under the slow rate condition. Despite a change in overall speaking rate, the nonfluent aphasics did not exhibit a significant difference in vowel duration at the two rates of speech, suggesting a deficit in the implementation of this temporal parameter. Both normal controls and fluent aphasic patients produced nonoverlapping distributions of tense and lax vowels at both speaking rates. In contrast, the nonfluent aphasics demonstrated a great deal of overlap in the distribution of tense and lax vowel durations at the fast rate. Results are discussed in relation to the nature of the speech production deficits in nonfluent and fluent aphasic patients.     

Sentence comprehension in aphasia in two clear case-marking languages

Studies of aphasia in Indo-European languages point to a selective vulnerability of morphological case marking in sentence comprehension. However, in case-marking languages such as German and Serbo-Croatian, the use of case marking to express formal grammatical gender diminishes the clarity of grammatical role marking. In Hungarian and Turkish, there are simple and reliable markings for the direct object. These markings are not linked to grammatical gender. Compared to Hungarian, the Turkish accusative marking is somewhat lower in availability, but somewhat higher in detectability. The processing of these cues by aphasics was tested using the design of MacWhinney, Pléh, and Bates (1985. Cognitive Psychology, 17, 178-209). Simple sentences with two nouns and one transitive verb were read to Broca's and Wernicke's aphasics, anomics, and control subjects in both Turkey and Hungary. The main effect of case marking was extremely strong. However, this was not true for all groups. The aphasics used the case cue far less than the normals, with the Hungarian Wernicke's group showing the greatest loss. Word order variations were largely ignored in all groups whenever the case-marking cue was present. When case marking was absent, Turkish subjects had a clear SOV interpretation for NNV sentences and Hungarians had a clear SVO interpretation for NVN sentences, in accord with basic patterns in their languages. When there was a contrast between the animacy of the two nouns, subjects choose the animate nouns significantly more often. The effect of animacy was particularly strong in Turkish, in accord with basic facts of Turkish grammar. In Hungarian, VNN sentences without case marking were interpreted as VOS when the first noun was inanimate. In Turkish, VNN sentences without case marking were often interpreted as VSO. In general, the aphasic subjects showed a clear preservation of virtually all aspects of their native languages, albeit in a much noisier form. Despite the high reliability of the case-marking cue, it was damaged more than the word order cue in English subjects. The near-chance processing of the case cue by the Wernicke's aphasics in Hungarian can probably be attributed to the relatively greater difficulty involved in detecting the Hungarian accusative suffix.     

Accessibility of case and gender contrasts for agent--object assignment in Broca's aphasics and fluent anomics

Yugoslav agrammatic Broca's aphasics, fluent anomics, and control subjects were tested for comprehension of agent-object relations in a series of simple Serbo-Croatian sentences in the conversational past tense, consisting of two nouns and a transitive action verb. The availability of two closed class cues--case contrasts and gender contrasts--as well as the availability of an open class lexical cue--animacy contrasts--was varied across sentences. An analysis of subjects' agent-object assignments yielded the following results: Both Broca's aphasics and fluent anomics showed a selective impairment in sensitivity to closed class morphology, although anomics were considerably less impaired than Broca's aphasics. This finding was interpreted as evidence for a non-syndrome-dependent vulnerability of abilities to process closed class morphology for comprehension. In addition, the pattern of agent-object assignments for Broca's aphasics revealed that the degree to which they were able to access the two closed class cues depended on a convergence of the various cues to agent-object relations. In particular, a convergence of case and gender contrasts had an interactive effect on Broca's responses: Gender agreement cues were accessed only in the presence of convergent case contrasts. Conversely, sensitivity to case contrasts was dramatically heightened in the presence of convergent gender contrasts. These results were consistent with a view that the two cues function as intrasentential "primes" or "retrieval cues" for one another.     

Functional categories in agrammatism: evidence from Greek

The aim of this study is twofold. First, to investigate the use of functional categories by two Greek agrammatic aphasics. Second, to discuss the implications of our findings for the characterization of the deficit in agrammatism. The functional categories under investigation were the following: definite and indefinite articles, personal pronouns, aspect, tense, subject-verb agreement, wh-pronouns, complementizers and the mood marker na (=to). Based on data collected through different methods, it is argued that the deficit in agrammatism cannot be described in terms of a structural account but rather by means of difficulties in the implementation of grammatical knowledge.     

Tense and Agreement Impairment in Ibero–Romance

We examine the inflectional productions of seven Catalan, seven Galician, and seven Spanish speaking agrammatic subjects in an elicitation and a sentence repetition task and consider them in the light of the Tree Pruning Hypothesis (TPH). The results show relatively spared subject person/number agreement with the verb and impaired tense marking for all subjects in all the languages. Recent reformulations of syntactic theory [Chomsky (1999) MIT Occasional Papers in Linguistics (vol. 18). MA: The MIT Press; (2000). Step by Step: Essays on Minimalist Syntax in Honor of Howard Lasnik (pp. 89–155). Cambridge, MA: The MIT Press] regarding the locus of agreement force a reconsideration of the TPH for it to make the desired predictions; we adopt Cinque’s [(1999) Adverbs and Functional Heads: A Cross-linguistic Perspective. Oxford: Oxford University Press] array of functional mood/tense/aspect projections and we show that subject agreement must occur between the subject DP and a low functional head for selective impairment to result. Feature underspecification, formerly considered, is rendered unnecessary.     

A crosslinguistic study of grammaticality judgments in Broca's aphasia

Crosslinguistic studies of sentence comprehension and production in Broca's aphasia have yielded two complementary findings: (1) grammatical morphology appears to be more impaired than word order principles in every language studied, but (2) the degree to which grammatical morphology is retained by aphasic patients depends upon the "strength" or importance of those morphemes in the patient's premorbid language. In an earlier study comparing violations of word order and agreement, we found that English-speaking Broca's aphasics showed greater sensitivity to errors of ordering than to errors of agreement, providing further evidence for the selective vulnerability of morphology. However, because English is a rigid word order language with a relatively weak inflectional system, it could be argued that word order is resilient to brain damage because it is the strongest source of information in this language. The present study compared the performance of English-speaking Broca's aphasics and normal controls with their Italian counterparts in the same grammaticality judgment experiment. Four predictions relating to our previous work were confirmed. (1) Italian aphasics, like their English-speaking counterparts, showed general preservation of grammatical knowledge and (2) they were able to use this knowledge in an "on-line" fashion. (3) Within each language, Broca's aphasics showed greater impairment in their ability to recognize errors of morphological selection (i.e., agreement) compared with errors made by moving the same words to an incorrect position downstream. Nevertheless (4), crosslinguistic differences observed in previous studies of comprehension and production were also observed in this grammaticality judgment task: a processing advantage for agreement errors in Italian normals and aphasics, and a processing advantage for ordering errors in English normals and aphasics.     

Immediate memory span, recognition memory for subspan series of words, and serial position effects in recognition memory for supraspan series of verbal and nonverbal items in Broca's and Wernicke's aphasia

Four Broca's aphasics, four Wernicke's aphasics, and four matched controls were investigated on three verbal and one visual short-term memory tasks. Experiment 1 considered memory span and subspan recognition memory for verbal items and Experiment 2 assessed serial position effects in supraspan verbal recognition memory. The Broca's aphasics demonstrated verbal memory deficits, which could not be attributed to linguistic disturbances, while the verbal memory deficiencies seen with the Wernicke's aphasics could be regarded as secondary to linguistic defects. In Experiment 3, where visual recognition memory was investigated, only the Broca's aphasics showed deficient performance. The wider context of deficient mnemonic performance in aphasia is discussed.     

Past Tense and Past Times in Subjunctive Conditionals

Some theories of conditionals maintain that the difference between indicative and subjunctive conditionals involves the standard temporal interpretation of past tense. I provide an argument against such theories. The argument is based on the claim that these views do not correctly predict the correspondence between tense marking and temporal interpretation in certain conditionals.     

Differential recovery in naming in bilingual aphasics

Language performance in a sample of 30 Catalan-Spanish bilingual aphasics was studied using three nominal tasks (naming, pointing, and translation). We compared performance between the two languages before and after therapy and also compared the improvements made in each language. Therapy was carried out in only one language, namely Catalan. Significant differences between the two languages were initially seen in the naming and translation tasks while after treatment significant differences were observed in the naming and pointing tasks. Analysis of covariance was carried out to control the influence of the initial performance on improvements. Performance in the naming task improved more in the treated language (Catalan) than in the nontreated language. We conclude that both differential impairment and recovery of languages in bilingual aphasics is seen not only in rare cases but also in studies of larger samples.     

Aphasic adults' understanding of complex adverbial sentences

Twelve aphasics with relatively preserved auditory comprehension were tested for their understanding of four adverbial sentence types expressing the temporal order of events. The relative effects of order of mention, adverbial choice, and adverbial clause placement on subjects' comprehension were investigated. Only adverbial choice was significant with aphasics producing more errors of temporal order on after than before sentences. Subjects' error patterns were not similar to those of children acquiring language. The results are discussed with respect to the theory of lexical marking and the regression hypothesis.     

Organization of and access to semantic memory in aphasia

Previous experiments with picture sorting and matching tasks have shown aphasics to give more deviant responses than controls when decisions require the identification of single features of concepts, whereas their responses are close to normal whenever decisions have to be based on the relative overlap of broad associative fields. The present experiment was designed to compare picture matching based on single features (property verification) with picture matching based on category membership (category verification). Fifty-five aphasics (14 amnesics, 18 Brocas, 13 Wernickes, 10 global aphasics) and 29 right-brain-damaged control patients served as subjects. Aphasics were poorer than right hemisphere controls on property as well as on category sortings, especially when the sorting criterion was not a dominant property of the object or when the object in question was not a typical member of the criterion category. Contrary to other studies, the "semantic distance" variable did not differentially affect Brocas as compared to Wernickes aphasics. Verbal labels denoting the sorting criterion and added to the picture presentation did not affect the performance of the right hemisphere controls but significantly improved that of the aphasics.     

Automatic and volitional semantic processing in aphasia.

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that object's semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.     

Semantic classification in aphasia: A study of basic, superordinate, and function relations

Nonfluent and fluent aphasics were given classification tasks that required the aphasics to identify three kinds of relations: same basic level category, same superordinate level category, and same function. The subjects received the items in word and picture form. In addition the aphasics were required to name the items they were asked to classify. The results showed that the ability to classify is more disrupted in fluent aphasia than in nonfluent aphasia. Within fluent aphasia, the degree to which classification is disrupted is dependent upon the type of relation being tested. While the overall performance of the fluent aphasics was depressed in comparison to nonfluent aphasics, it was significantly more depressed on function relations. The ability to name an item had a significant effect on the ability to classify only for basic level items.     

Syntactic and semantic processes in aphasic deficits: The availability of prepositions

The availability of a specific category of closed class items (prepositions) was examined in Broca's and Wernicke's aphasia. The role of prepositions was varied (syntactic/semantic) in two tasks: one requiring production of prepositions and the other acceptability judgments. Overall, it was easier to perform the acceptability task than to produce the target item. In the judgment task, Wernicke's aphasics more accurately determined the acceptability of prepositions in their syntactic role than in their semantic role, but Broca's aphasics showed no such difference. In the production task, Wernicke's aphasics again were more likely to produce prepositions which were in a primarily syntactic role. Broca's aphasics, however, failed to produce such syntactically based prepositions. The results suggest that the availability of a given closed class vocabulary form is not merely a function of its class membership but also of its functional role, and this fact serves to distinguish aspects of Broca's and Wernicke's aphasics' deficit.     

Agrammatic production of subject-verb agreement: the effect of conceptual number.

Three experiments tested the hypothesis that the deficit underlying agrammatic sentence production difficulties can be characterized as a limitation of computational resources and that these resources are not restricted to syntactic processing. This hypothesis was tested by eliciting subject-verb agreement errors in a sentence fragment completion paradigm. Sentence fragments were complex noun phrases, containing a subject (head) noun and a modifying prepositional phrase, containing a "local" noun. We varied the number of "tokens" a singular head noun referred to. Therefore, in one condition, grammatical and conceptual number of the head noun mismatched, whereas these numbers were the same in another condition. In Experiments 1 and 2, we observed an effect of this variable (i.e., more agreement errors when conceptual number was plural and grammatical number singular) in normal controls. Broca's aphasics, on the other hand, showed no effect. Experiment 3 consisted of a sentence/picture matching test. This test showed that the lack of effect with Broca's aphasics cannot be attributed to a comprehension deficit. We argue that these results are incompatible with the notion of a limitation in resources specific for syntactic processing. Instead, we interpret this as the result of a trade-off: Broca's aphasics lack computational resources to take into account both grammatical and conceptual information in morphosyntactic processing and rely on grammatical information only.     

Impairment of inflectional morphology and lexical storage.

The present study investigates the repetition, comprehension, and production abilities of three French-speaking agrammatic aphasics on stimuli that require attention to the inflectional markers of number, gender, and tense. Two sets of experiments were conducted within a Strong Lexicalist framework. The results suggest that morphological deficits can manifest themselves at distinct levels of grammar, the lexical and the postlexical. The internal morphological structure and idiosyncracies of lexical items were found to have an effect on aphasic performance. A proposal of a differentially organized lexical storage reflecting the particularities of the French verbal system is put forth. The storage hypothesis suggested for verbs is extended to other lexical items.     

Inflection and computational load in agrammatic speech

In this study we investigate the production of verb inflection in agrammatic aphasia. In a number of recent studies it has been argued that tense inflection is harder to produce for agrammatic individuals than agreement inflection. However, results are still inconclusive, at least for Dutch and German. Here, we report three experiments in which this matter is further investigated. Our first goal was to determine whether tense was indeed more difficult to produce than agreement. Also, we investigated whether error rates were influenced by computational load. The results for nine Dutch-speaking agrammatic participants generally indicated that tense was indeed harder to produce than agreement, but that for both types of inflection, the number of errors increased with computational load. Taking care of word order and inflection induced more errors than taking care of just inflection. These findings are discussed in relation to current processing and representational models of agrammatic production.