Passives in agrammatic sentence comprehension: A German study

Background: A large number of studies examining agrammatic comprehension of canonical and non‐canonical sentences in Broca's aphasia have focused on passives and results have been interpreted in theoretical frameworks such as the trace deletion hypothesis (TDH: Grodzinsky, 1995a). However, there are a number of unresolved issues associated with passives. The linguistic analysis of passive structures in different languages has remained controversial as well as the empirical neurolinguistic basis of agrammatic passive comprehension. In addition, a variety of morphological and semantic questions have been raised with respect to the implicit argument in short passives and the ordering of thematic roles reflected by different positions of the by‐phrase in long passives. Aims: The major aims of the present study were to re‐examine the analyses of passives with and without traces, the role of an implicit argument in short passives, and the influence of the position of the by‐phrase on agrammatic sentence comprehension. Methods & Procedures: A binary picture–sentence matching task was administered to six non‐fluent German agrammatic speakers. Various types of passives including long, short, and topicalised passives were tested. Additionally, comprehension of active SVO sentences was assessed in a separate but similar session. Only those patients whose comprehension on active sentences was above chance were included. Outcomes & Results: As a group, the six subjects performed above chance over all passive types. If only long canonical passives are considered, as is done in most studies, five subjects showed a pattern compatible with the TDH. However, the picture was modified if other passive constructions were taken into account, in which case only three of the six subjects showed TDH conformity. Conclusions: There is no unique pattern of agrammatic passive comprehension and only half of the agrammatic subjects conformed to the trace deletion hypothesis. Given the results on long canonical and topicalised passives, our data support linguistic analyses that assume a trace‐based derivation of passives. Furthermore, the results are in line with linguistic analyses adopting an implicit argument in short passives. Since comprehension of topicalised passives with a canonical order of theta‐roles was not better than that of long passives without a canonical order, the agrammatic problem with passives does not seem to hinge on semantics.     

Non-fluent aphasia in Ibero-Romance: a review of morphosyntactic deficits

Background: Castilian-Spanish, Catalan, Galician, and European Portuguese are the most widely spoken languages of the Ibero-Romance group. An increasing number of authors have addressed the impact of aphasia on the morphosyntax of these varieties. However, accurate linguistic characterisations are scarce and the different sources of data have not been yet compiled.

Aims: To stimulate state-of-the-art research, we provided a comprehensive summary of morphosyntactic aspects of Ibero-Romance and a review of how these are affected in non-fluent aphasia. The topics we dealt with are the use of verb argument structure and morphology, sentential negation and word order, definite articles, personal and reflexive pronouns, passives, topicalised constructions, questions, and relative clauses.

Methods & Procedures: An exhaustive fieldwork and search of PubMed, Web of Science, and Medline records were performed to retrieve studies focused on morphosyntactic issues concerning the Ibero-Romance varieties. A total of 27 studies produced by 46 authors of varying background emerged. We did not review studies of category-specific deficits and aspects related to bilingual aphasia, although we assume that most speakers of Galician and Catalan are bilingual. Studies of spontaneous speech were included when no controlled experimental tasks were available.

Outcomes & Results: The morphosyntactic commonalities of Ibero-Romance have been tackled from different theoretical perspectives. There exist asymmetries in findings which we explain with the use of different tasks (and task complexity) and individual differences between participants.

Conclusions: Discourse-linking factors as well as deviations from the canonical pattern are recurrent answers to these asymmetries. A comprehensive theory of impairments in non-fluent aphasia integrating relevant aspects of both structural and processing accounts seems necessary.     

The languages of aphasia research: Bias and diversity

Background: It is widely believed that the vast majority of articles on aphasia published in international journals are based on observations of English-speaking patients, with a possible more general bias towards western European languages. However, to the best of our knowledge no systematic study has tried to quantify linguistic biases in aphasia research.

Aims: To examine the current (first decade of the twenty-first century) representation of different languages in aphasia literature.

Methods & Procedures: We examined all articles on aphasia published between 2000 and 2009 in four leading aphasiological journals: Aphasiology, Brain and Language, Journal of Neurolinguistics, and Language and Cognitive Processes, determining the language(s) spoken by the patients. We compared the proportion of articles in a given language with the estimated number of its speakers worldwide. We further analysed the relationship between the language and the methodology, content, and number of citations as well as trends applying to individual journals and changes over time.

Outcomes & Results: There was a pronounced overall bias towards articles based on observations of English-speaking patients, accounting for 62% of all papers, 85% of papers on aphasia treatment, and 100% of papers that received more than 50 citations. More generally, there was a strong bias towards western European (Germanic and Romance) languages, accounting for 89% of all papers and 96% of treatment studies. In contrast, non-Indo-European languages, as well as the Slavonic and the Indo-European languages of India were strongly under-represented. Some of the most widely spoken languages in the world, such as Arabic, Hindi, Bengali, Russian, as well as Portuguese, accounted for less than 0.5% of the aphasia literature. This imbalance has not improved over the examined time period; in fact, the percentage of papers on English seems to be increasing.

Conclusions: The current aphasia literature is not representative of the world's languages, neither in terms of linguistic typology nor the number of speakers. The extreme bias towards English and other western European languages limits the worldwide applicability of clinical findings (in particular in aphasia therapy) and undermines the universality of theoretical models, which are based on observations from a small number of closely related languages. We conclude that development of a more cross-linguistic approach to aphasia should be one of the priorities in future aphasia research.     

Noun and verb knowledge in monolingual preschool children across 17 languages: Data from Cross-linguistic Lexical Tasks (LITMUS-CLT)

ABSTRACT

This article investigates the cross-linguistic comparability of the newly developed lexical assessment tool Cross-linguistic Lexical Tasks (LITMUS-CLT). LITMUS-CLT is a part the Language Impairment Testing in Multilingual Settings (LITMUS) battery (Armon-Lotem, de Jong & Meir, 2015). Here we analyse results on receptive and expressive word knowledge tasks for nouns and verbs across 17 languages from eight different language families: Baltic (Lithuanian), Bantu (isiXhosa), Finnic (Finnish), Germanic (Afrikaans, British English, South African English, German, Luxembourgish, Norwegian, Swedish), Romance (Catalan, Italian), Semitic (Hebrew), Slavic (Polish, Serbian, Slovak) and Turkic (Turkish). The participants were 639 monolingual children aged 3;0–6;11 living in 15 different countries. Differences in vocabulary size were small between 16 of the languages; but isiXhosa-speaking children knew significantly fewer words than speakers of the other languages. There was a robust effect of word class: accuracy was higher for nouns than verbs. Furthermore, comprehension was more advanced than production. Results are discussed in the context of cross-linguistic comparisons of lexical development in monolingual and bilingual populations.     

Tests of syntactic comprehension in aphasia: An investigation of task effects

Background: Consistency of performance across tasks that assess syntactic comprehension in aphasia has clinical and theoretical relevance. In this paper we add to the relatively sparse previous work on how sentence comprehension abilities are influenced by the nature of the assessment task.

Aims: Our aims are: (1) to compare linguistic performance across sentence–picture matching, enactment, and truth‐value judgement tasks; (2) to investigate the impact of pictorial stimuli on syntactic comprehension.

Methods & Procedures: We tested a group of 10 aphasic speakers (3 with fluent and 7 with non‐fluent aphasia) in three tasks (Experiment 1): (i) sentence–picture matching with four pictures, (ii) sentence–picture matching with two pictures, and (iii) enactment. A further task of truth‐value judgement was given to a subgroup of those speakers (n = 5, Experiment 2). Similar sentence types across all tasks were used and included canonical (actives, subject clefts) and non‐canonical (passives, object clefts) sentences. We undertook two types of analyses: (a) we compared canonical and non‐canonical sentences in each task; (b) we compared performance between (i) actives and passives, (ii) subject and object clefts in each task. We examined the results of all participants as a group and as case‐series.

Outcomes & Results: Several task effects emerged. Overall, the two‐picture sentence–picture matching and enactment tasks were more discriminating than the four‐picture condition. Group performance in the truth‐value judgement task was similar to two‐picture sentence–picture matching and enactment. At the individual level performance across tasks contrasted to some group results.

Conclusions: Our findings revealed task effects across participants. We discuss reasons that could explain the diverse profiles of performance and the implications for clinical practice.     

Assessing syntactic deficits in Chinese Broca’s aphasia using the Northwestern Assessment of Verbs and Sentences-Chinese (NAVS-C)

Background: English-speaking patients with Broca’s aphasia and agrammatism evince difficulty with complex grammatical structures, including verbs and sentences. A few studies have found similar patterns among Chinese-speaking patients with Broca’s aphasia, despite structural differences between these two languages. However, no studies have explicitly examined verb properties, including the number and optionality of arguments (participant roles) selected by the verb, and only a few studies have examined sentence deficits among Chinese patients. In addition, there are no test batteries presently available to assess syntactically important properties of verbs and sentences in Chinese patients.

Aims: This study used a Chinese version of the Northwestern Assessment of Verbs and Sentences (NAVS), originally developed for English speakers with aphasia, to examine the verb and sentence deficit patterns among Chinese speakers with aphasia. As in the original NAVS, the Chinese version (NAVS-C) assessed verbs by the number and optionality of arguments as well as sentence canonicity, in the both production and comprehension.

Methods and Procedures: Fifteen Chinese patients with Broca’s aphasia and 15 age-matched healthy normal controls participated in this study. All NAVS-C tests were administered, in which participants were asked either to produce or to identify verbs and sentences coinciding with action pictures.

Outcomes & Results: Despite grammatical differences between Chinese and English, the impairment caused by the structural complexity of verbs and sentences was replicated in Chinese-speaking patients using the NAVS-C. Verbs with more arguments were significantly more impaired than those with fewer arguments and verbs with optional arguments were significantly more impaired than those with obligatory arguments. One deviation from English-speaking patients, however, is that the Chinese-speaking patients exhibited greater difficulty with subject relative clauses than with object relative clauses because the former, rather than the latter, involve noncanonical order in Chinese. Similar to English-speaking patients, Chinese patients exhibited more difficulty with object-extracted wh-questions than with subject-extracted wh-questions, suggesting that wh-movement in Logical Form may also cause processing difficulty. Moreover, Chinese-speaking patients exhibited similar performance in both production and comprehension, indicating the deficits in both modalities.

Conclusions: The number and optionality of verb arguments as well as the canonicity of the Agent–Theme order in sentences impact Chinese-speaking individuals with aphasia as they do in the case of English-speaking patients. These findings indicate that the NAVS-C is a useful tool for detailing deficit patterns associated with syntactic processing in patients with aphasia cross-linguistically.     

Sentence production in Swahili–English bilingual agrammatic speakers

Background: It has been argued that agrammatic speakers' production of sentences in derived order is impaired (The Derived Order Problem Hypothesis, DOP-H), and that the underlying deficit in bilingual individuals with agrammatic Broca's aphasia may cause different surface manifestations in the languages when they differ in terms of their grammatical morphology. The current study presents results of a study on sentence production in Swahili-English bilingual agrammatic speakers. The two languages, Swahili and English, differ significantly in terms of their verbal morphology.

Aims: The current study tested the production of sentences in base and derived orders of arguments in the two languages of Swahili-English bilingual agrammatic speakers.

Methods & Procedures: Eight agrammatic and eight non-brain damaged individuals participated in the study. A sentence elicitation test was used to examine the production of sentences in base and derived word orders in Swahili and English. The base order condition consisted of active and subject-cleft sentences, whereas the derived order condition tested passive and object-cleft sentences.

Outcomes & Results: The non-brain-damaged individuals performed at ceiling in both languages. The agrammatic speakers' results, however, show sentences in derived order condition and were more difficult to produce than those in base order, similarly across the two languages irrespective of their morphological differences. Moreover, the embedded sentences were also more difficult to produce than simple sentences for agrammatic speakers.

Conclusions: The current data partially support the DOP-H and provide new insight into sentence production deficit of bilingual individuals with agrammatic Broca's aphasia. The findings are discussed with respect to the theories of sentence production in agrammatic speakers.     

The comprehension of sentences with unaccusative verbs in aphasia: a test of the intervener hypothesis

Background: It is well accepted that individuals with agrammatic Broca’s aphasia have difficulty comprehending some sentences with filler-gap dependencies. While investigations of these difficulties have been conducted with several different sentence types (e.g., object relatives, Wh-questions), we explore sentences containing unaccusative verbs, which arguably have a single noun phrase (NP) that is base-generated in object position but then is displaced to surface subject position. Unaccusative verbs provide an ideal test case for a particular hypothesis about the comprehension disorder—the Intervener Hypothesis—that posits that the difficulty individuals with agrammatic Broca’s aphasia have comprehending sentences containing filler-gap dependencies results from similarity-based interference caused by the presence of an intervening NP between the two elements of a syntactic chain.

Aim: To assess a particular account of the comprehension deficit in agrammatic Broca’s aphasia—the Intervener Hypothesis.

Methods & Procedures: We used a sentence–picture matching task to determine if listeners with agrammatic Broca’s aphasia (LWBA) and age-matched neurologically unimpaired controls (AMC) have difficulty comprehending unaccusative verbs when placed in subject relative and complement phrase (CP) constructions.

Outcomes & Results: We found above-chance comprehension of both sentence constructions with the AMC participants. In contrast, we found above-chance comprehension of CP sentences containing unaccusative verbs but poor comprehension of subject relative sentences containing unaccusative verbs for the LWBA.

Conclusions: These results provide support for the Intervener Hypothesis, wherein the presence of an intervening NP between two elements of a filler-gap dependency adversely affects sentence comprehension.     

Grammar and cognition: deficits comprehending counterfactuals in Turkish individuals with Broca’s aphasia

Background: Comprehending counterfactuals requires a well-developed cognitive system. Individuals with Broca’s aphasia have impaired cognitive functioning, which may affect their ability to comprehend counterfactuals.

Aims: This study investigated whether cognitive complexity involved in counterfactuals adds to sentence comprehension deficits in Broca’s aphasia.

Methods & Procedures: The sample consisted of 24 Turkish individuals with Broca’s aphasia (mean age: 52.7; SD: 12.7) who were matched in age with a control group of 15 neurologically intact Turkish individuals (mean age: 51.8; SD: 8.5). Each group completed a sentence comprehension task with three sentence conditions: nonconditional, factual, and counterfactual. Nonconditionals did not have if-embedding, whereas factual and counterfactual conditionals were morphosyntactically equivalent if-clauses, but only the latter was cognitively complex.

Outcomes & Results: Conditionals were more difficult to comprehend than nonconditionals for the Broca group. Counterfactuals were more difficult to comprehend than the morphosyntactically equivalent factual counterparts for the Broca group. There was no discrepancy between test conditions for the control group.

Conclusions: Individuals with Broca’s aphasia have difficulty processing counterfactuals due to morphosyntactic complexity (if-embedding) and the cognitive processes involved in comprehending counterfactuals. This indicates that cognitive complexity adds to sentence comprehension deficits in Broca’s aphasia.     

Effects of verb bias and syntactic ambiguity on reading in people with aphasia

Background: The Lexical Bias Hypothesis claims that people with aphasia (PWA) have difficulty understanding sentences when the verb’s argument structure bias conflicts with the sentence structure. This hypothesis can account for comprehension deficits that affect simple sentences, but the role of verb bias has not been clearly demonstrated in temporarily ambiguous sentences.

Aims: This study examined how verb bias affects comprehension of temporarily ambiguous and unambiguous sentences using self-paced reading.

Methods & Procedures: PWA and controls read sentences that contained sentential complements (e.g., The talented photographer accepted (that) the fire could not have been prevented). The main verb was biased to take a direct object (e.g., accepted) or a sentential complement (e.g., admitted). In addition, the sentential complement was either introduced by the complementiser that (i.e., unambiguous) or unmarked (i.e., ambiguous).

Results: The reading times of PWA were affected more by verb bias than by the presence of the complementiser, whereas the control group’s reading times were more affected by the presence or absence of the complementiser.

Conclusions: The results were generally consistent with the Lexical Bias Hypothesis, and showed that a mismatch between verb bias and sentence structure affected the processing of unambiguous and temporarily ambiguous sentences in PWA.     

Verb transitivity bias affects on-line sentence reading in people with aphasia

Background: Studies of sentence comprehension in non-disordered populations have convincingly demonstrated that probabilistic cues influence on-line syntactic processing. One well-studied cue is verb argument structure bias, which refers to the probability that a verb will occur in a particular syntactic frame. According to the Lexical Bias Hypothesis people with aphasia have difficulty understanding sentences in which the verb's argument structure bias conflicts with the sentence structure (e.g., a transitively biased verb in an intransitive sentence). This hypothesis may provide an account of why people with aphasia have difficulty understanding both simple and complex sentences.

Aims: The purpose of this study was to test the Lexical Bias Hypothesis using an on-line measure of written sentence comprehension, self-paced reading.

Methods & Procedures: The participants were 10 people with aphasia and 10 non-brain-damaged controls. The stimuli were syntactically simple transitive and intransitive sentences that contained transitively or intransitively biased verbs. For example, the transitively biased verb “called” appeared in sentences such as “The agent called (the writer) from overseas to make an offer.” The intransitively biased verb “danced” appeared in sentences such as “The couple danced (the tango) every Friday night last summer.”

Outcomes & Results: Both groups' reading times for critical segments were longer when the verb's transitivity bias did not match the sentence structure, particularly in intransitive sentences.

Conclusions: The results were generally consistent with the Lexical Bias Hypothesis, and demonstrated that lexical biases affect on-line processing of syntactically simple sentences in people with aphasia and controls.     

The interpretation of stressed and non-stressed pronouns in Spanish language breakdown

Background: Earlier research has indicated that patients with agrammatic Broca's aphasia have problems with constraints on the intra-sentential interpretation of object pronouns, incorrectly allowing them to refer to the subject of the same sentence. However, these studies do not show how agrammatic patients deal with constraints on the extra-sentential interpretation of pronouns. Also, studies that did investigate patients' extra-sentential interpretation of pronouns were on English and Dutch, languages with a pronominal system that differs substantially from the pronominal system of Romance languages, such as Spanish.

Aims: To test Spanish agrammatic patients on the interpretation of stressed and non-stressed subject and object pronouns in coordinated structures (the Spanish counterparts of sentences such as “First the girl pushed the mother, and than she / SHE pushed the boy”), in order to investigate whether they exhibit the same referential preferences as non-brain-damaged individuals and English- and Dutch-speaking patients.

Methods & Procedures: In the present study seven Spanish patients with agrammatic Broca's aphasia and six non-brain-damaged adults were tested with a picture selection task on their interpretation of non-stressed and stressed pronouns in coordinated sentences. Patients were presented coordinated sentences and were shown four pictures, one on the left page, three on the right page. The left page picture represents the first conjunct of the test sentence, the right page represent the two theoretically possible referents of the pronoun (subject of the first conjunct, or object of the first conjunct) and a non-related picture. The patient's task was to indicate out of the three pictures the one that correctly represented the meaning of the second conjunct of the test sentence.

Outcomes & Results: Agrammatic individuals exhibit difficulties with the interpretation of non-stressed object pronouns, and even more difficulties with the interpretation of contrastively stressed pronouns. An additional finding is that they tend to prefer subjects as the antecedents of pronouns.

Conclusions: We claim that patients' problems with the interpretation of pronouns are not the result of missing syntactic knowledge, but are due to patients' limited ability to keep syntactic configurations in their syntactic working memory. We argue that their preference for subjects as antecedents for pronouns reflects a fall-back strategy in agrammatic patients when, as a result of limited processing resources, syntax-based interpretative operations fail.     

Verb and sentence production and comprehension in aphasia: Northwestern Assessment of Verbs and Sentences (NAVS)

Background: Verbs and sentences are often impaired in individuals with aphasia, and differential impairment patterns are associated with different types of aphasia. With currently available test batteries, however, it is challenging to provide a comprehensive profile of aphasic language impairments because they do not examine syntactically important properties of verbs and sentences.

Aims: This study presents data derived from the Northwestern Assessment of Verbs and Sentences (NAVS; Thompson, 2011 Thompson, C. K. 2011. Northwestern Assessment of Verbs and Sentences Evanston, IL [Google Scholar]), a new test battery designed to examine syntactic deficits in aphasia. The NAVS includes tests for verb naming and comprehension, and production of verb argument structure in simple active sentences, with each examining the effects of the number and optionality of arguments. The NAVS also tests production and comprehension of canonical and non-canonical sentences.

Methods & Procedures: A total of 59 aphasic participants (35 agrammatic and 24 anomic) were tested using a set of action pictures. Participants produced verbs or sentences for the production subtests and identified pictures corresponding to auditorily provided verbs or sentences for the comprehension subtests.

Outcomes & Results: The agrammatic group, compared to the anomic group, performed significantly more poorly on all subtests except verb comprehension, and for both groups comprehension was less impaired than production. On verb naming and argument structure production tests both groups exhibited difficulty with three-argument verbs, affected by the number and optionality of arguments. However, production of sentences using three-argument verbs was more impaired in the agrammatic, compared to the anomic, group. On sentence production and comprehension tests, the agrammatic group showed impairments in all types of non-canonical sentences, whereas the anomic group exhibited difficulty primarily with the most difficult, object relative, structures.

Conclusions: Results show that verb and sentence deficits seen in individuals with agrammatic aphasia are largely influenced by syntactic complexity; however, individuals with anomic aphasia appear to exhibit these impairments only for the most complex forms of verbs and sentences. The present data indicate that the NAVS is useful for characterising verb and sentence deficits in people with aphasia.     

Overcoming discourse-linking difficulties in aphasia: The case of clitic pronouns

The present study aims to contribute to the ongoing discussion about the impact of discourse-linking deficits on the performance of individuals with aphasia by providing new data from a set of rarely investigated constructions: sentences in which a clitic pronoun coexists alongside with the full DP it agrees with. To do so, we use data of individuals with non-fluent aphasias who need to overcome the difficulties in direct object (accusative) clitic production. This results in overproduction of non-target clitic right dislocations (RDs) and clitic doubling (CD). Data from 15 individual’s native speakers of Spanish and Catalan are discussed. Data complement the results of previous investigations on discourse-linking effects in these languages, allowing the interpretation of results across constructions.     

Does phonological working memory impairment affect sentence comprehension? A study of conduction aphasia

Background: The nature of the relation between phonological working memory and sentence comprehension is still an open question. This question has theoretical implications with respect to the existence of various working memory resources and their involvement in sentence processing. It also bears clinical implications for the language impairment of patients with phonological working memory limitation, such as individuals with conduction aphasia.

Aims: This study explored whether limited phonological working memory impairs sentence comprehension in conduction aphasia.

Methods & Procedures: The participants were 12 Hebrew-speaking individuals with conduction aphasia who, according to 10 recall and recognition span tasks, had limited phonological short-term memory in comparison to 296 control participants. Experiments 1 and 2 tested their comprehension of relative clauses, which require semantic-syntactic reactivation, using sentence–picture matching and plausibility judgement tasks. Experiments 3 and 4 tested phonological reactivation, using two tasks: a paraphrasing task for sentences containing an ambiguous word in which disambiguation requires re-accessing the word form of the ambiguous word, and rhyme judgement within sentences. In each task the distance between a word and its reactivation was manipulated by adding words/syllables, intervening arguments, or intervening embeddings.

Outcomes & Results: Although their phonological short-term memory, and hence their phonological working memory, was very impaired, the individuals with conduction aphasia comprehended relative clauses well, even in sentences with a long distance between the antecedent and the gap. They failed to understand sentences that required phonological reactivation when the phonological distance was long.

Conclusions: The theoretical implication of this study is that phonological working memory is not involved when only semantic-syntactic reactivation is required. Phonological working memory does support comprehension in very specific conditions: when phonological reactivation is required after a long phonological distance. The clinical implication of these results is that because most of the sentences in daily language input can be understood without phonological reactivation, individuals with phonological working memory impairment, such as individuals with conduction aphasia, are expected to understand sentences well, as long as they understand the meaning of the sentences and do not attempt to repeat them or encode them phonologically.     

A potential confound does not a theory make: Comment on Salis and Edwards (2006)

Background: Morphological errors of tense and agreement are salient in agrammatic aphasia. The PADILIH predicts impairments in discourse linking that translate to greater difficulties in referring to a past event time than to a future or a present event time. In Catalan, the Periphrastic conditional tense (e.g., “if the man had had time, he would have…”) refers to the past and the Simple conditional tense refers to the future (e.g., “if the man had time, he would…”). These two tenses refer to an event that may happen (irrealis).

Aims: We fill in the gap of the conditional tense and provide further data to study contrasts in verb inflection for time reference. We predict that verb forms that refer to an irrealis past event (Periphrastic conditional) are more impaired than forms that refer to an irrealis future event (Simple conditional and Future). We also predict that there are no differences between verb forms that refer to an irrealis future event (Simple conditional and Future). We also assessed whether problems in time reference extend to individuals with non-fluent aphasia that are not typical agrammatic Broca aphasia.

Methods &; Procedures: A sentence completion task that included 60 sentences (20 per type) of equal length in a Conditional structure (if-sentences) was designed. We tested three sentence types: Periphrastic conditional, Simple conditional and Future. The task was administered to nine participants with non-fluent aphasia and nine age-matched non-brain-damaged participants.

Outcomes &; Results: The Control group scored at ceiling on the three sentence types. Participants with non-fluent aphasia were most impaired in the production of the Periphrastic conditional as compared with the Simple conditional and the Future.

Conclusions: When irrealis event times are compared, past events are more impaired than future events. These results can be explained by a deficit in time reference as predicted by the PADILIH. Our data reveal that the predictions of the PADILIH also hold for non-fluent speakers who have been diagnosed with Transcortical motor aphasia.     

Tap and trill clusters in typical and protracted phonological development: Challenging segments in complex phonological environments. Introduction to the special issue

ABSTRACT

The papers in this crosslinguistic issue address children’s acquisition of word-initial rhotic clusters in languages with taps/trills, that is, the acquisition of challenging segments in complex environments. Several papers also include comparisons with singleton rhotics and/or /l/ as a singleton or in clusters. The studies are part of a larger investigation that uses similar methodologies across languages in order to enhance crosslinguistic comparability (Bernhardt and Stemberger, 2012, 2015). Participants for the current studies were monolingual preschoolers with typical or protracted phonological development who speak one of the following languages: Germanic (Icelandic/Swedish); Romance (Portuguese/Spanish); Slavic (Bulgarian/Slovenian) and Finno-Ugric (Hungarian). This introductory paper describes characteristics of taps/trills and general methodology across the studies, concluding with predicted patterns of acquisition. The seven papers that follow are in a sense the ‘results’ for this introduction. A concluding paper discusses major findings and their implications for theory, research and clinical practice.     

Verb processing in Basque and French agrammatic aphasia: A “post-lexical access” deficit

Background: Verb processing is largely described across languages as being impaired in agrammatic aphasia, i.e., non-fluent aphasia with so-called “telegraphic style”. Although both lexical and morphosyntactic errors have been reported in the literature, this paper questions the claim that impaired access to verbs is a hallmark of this clinical syndrome.

Aims: The present study aims to assess how agrammatic verb processing is impaired in two languages with distinct grammatical properties: Basque and French, and to test hypotheses that suggested an access deficit to verbs on this new database. Moreover, the nature of agrammatic verb errors is analysed from an interdisciplinary neuropsycholinguistic perspective according to which aphasic symptoms should be interpretable at different levels of organisation of language processing involving neural, cognitive and linguistic aspects.

Methods & Procedures: A protocol built on Basque and French grammatical properties was designed in order to assess whether errors are specific to verbs, whether they are lexical or morphosyntactic and whether the verb argument structure complexity increases lexical and morphosyntactic processing difficulties, in both production and comprehension. One Basque-speaking and one French-speaking patient with agrammatism and matched controls were assessed on various oral tasks (object and action naming; sentence production and comprehension; prepositional phrase production), each of them containing 20 pictures displayed on a computer. Data were collected using a digital recorder.

Outcomes & Results: Results show that agrammatic speakers produced many lexical verbs of every argument structure type. Errors were specifically morphosyntactic and increased with the verb argument structure complexity. However, verb errors were different in Basque and French due to their distinct morphosyntactic properties. In addition, whereas errors appeared in French in the use of prepositions, case morphology was well preserved in Basque, raising the issue of considering distinct neurocognitive mechanisms underlying different morphological systems.

Conclusions: This paper supports the view that Basque and French agrammatic data collected from this study do not result from a lexical-access deficit. However, this interpretation depends on how one considers inflected verbs to be processed (endolexicon or exolexicon), as addressed in the discussion. In conclusion, a “post-lexical access” deficit is rather suggested, that is prior to morphophonological encoding, and affects abstract morphosyntactic operations required to implement the verb argument structure.     

“I don’t know”: a usage-based approach to familiar collocations in non-fluent aphasia

Background: Familiar collocations (e.g., “it’s alright”) are an important part of everyday conversation. Such word combinations are often retained in speakers with Broca’s aphasia. However, only few investigations have studied the forms and functions of familiar collocations available to speakers with Broca’s aphasia.

Aims: We first apply a frequency-based perspective to word combinations produced by speakers with Broca’s aphasia and their conversation partners (CPs), and compare the frequency characteristics of word combinations in dyadic and non-dyadic speech. Second, we investigate the conversational functions of one prominent familiar collocation, “I don’t know” (IDK).

Methods & Procedures: In the first analysis, speech samples from interactions of nine dyads (each a speaker with Broca’s aphasia and their CP) were examined. Non-dyadic samples were selected from 39 speakers with Broca’s aphasia from AphasiaBank (MacWhinney et al., 2011). The Frequency in Language Analysis Tool (FLAT; Zimmerer & Wibrow, 2015) was used to estimate collocation strength (the degree of association between words in a combination) of well-formed bigrams (two-word combinations) and trigrams (three-word combinations). The second analysis presents a qualitative investigation of uses of IDK in dyadic exchanges.

Outcomes & Results: Analysis 1 revealed that residual trigrams in Broca’s aphasia were more strongly collocated in comparison to language produced by CPs. There was no difference in frequency-based profiles between dyadic and non-dyadic aphasic speech. Analysis 2 indicated that speakers with Broca’s aphasia and CPs used IDK to achieve a variety of communicative functions. However, patterns specific to each participant group were found.

Conclusions: These findings highlight that frequency-based analysis is useful in explaining residual, grammatically well-formed word combinations in Broca’s aphasia. This study provides evidence that IDK can aid turn construction in aphasia.