Towards an Explanation for the Foreign Accent in the Foreign Accent Syndrome: the Role of Fortition (2024)

Brain and Language, 1998

Language Processing: New Research (pp. 1-32), 2014

D41. CASES IN THORACIC SURGERY, PULMONARY VASCULAR DISEASE, TRANSPLANTATION, AND CONGENITAL ABNORMALITIES, 2010

Frontiers in human neuroscience, 2016

Background: Demographic and clinical predictors of aphasia recovery have been identified in the literature. However, little attention has been devoted to identifying and distinguishing predictors of improvement for different outcomes, e.g., production of treated vs. untreated materials. These outcomes may rely on different mechanisms, and therefore be predicted by different variables. Furthermore, treatment features are not typically accounted for when studying predictors of aphasia recovery. This is partly due to the small numbers of cases reported in studies, but also to limitations of data analysis techniques usually employed. Method: We reviewed the literature on predictors of aphasia recovery, and conducted a meta-analysis of single-case studies designed to assess the efficacy of treatments for verb production. The contribution of demographic, clinical, and treatment-related variables was assessed by means of Random Forests (a machine-learning technique used in classification a...

The aim of this paper is to give an overview of research in the field of clinical linguistics focusing on several closely related South Slavic languages, namely Bosnian, Croatian, Montenegrin and Serbian (BCMS or Serbo-Croatian). It summarizes studies of genetic, developmental and acquired disorders conducted with participants who are native speakers of one of these languages, including Down syndrome, Specific Language Impairment and aphasia. As studies of language deficits in these four languages are still rather scarce, the paper concludes with a brief discussion and a set of suggestions for future research in the field of clinical linguistics.

Frontiers in Behavioral Neuroscience, 2015

Aphasiology, 2006

Aphasiology, 2013

Background: Production of verb morphology, especially tense marking, is frequentlyimpaired in persons with agrammatic aphasia. Very little research has examined theoreticallydriven treatments for verb morphology deficits in aphasia.Aims: This study examined the relative efficacy of using regular (wash-washed,rob-robbed) versus irregular (drink-drank, keep-kept) verbs as stimuli to treat morphologicalimpairments in individuals with aphasia. This comparison was motivatedby differences in the lexical organisation of regular and irregular verbs proposed inpsycholinguistic theory.Methods & Procedures: A single-participant multiple-baseline design was used to examinetreatment outcomes in six individuals with agrammatic aphasia. Participants receivedtraining to produce tense morphology using only either regular or irregular verbs, andthe crucial outcome measure was generalisation to untrained past tense forms (regular toirregular and vice versa).Outcomes & Results: All participants improved in the trained tenses and generalised to theproduction of regular tense morphology on untrained verbs. Generalisation to untrainedirregular past tense was relatively modest, irrespective of whether regular or irregularverbs were trained.Conclusions: The results replicate previous findings that verb morphology deficits respondto intervention, and extend the findings by suggesting that choice of stimuli may haveconsequences for generalisation effects. The implication for aphasia rehabilitation is thattense training using irregularly inflected verbs generalises to a greater variety of untrainedverb inflections (including regular past) than does the use of regular verbs.

Aphasiology, 2011

Brain and language, 2004

Clinical linguistics & phonetics, 2018

While growing evidence reports changes in language use in non-demented individuals with Parkinson's disease (PD), the presence and nature of the deficits remain largely unclear. Researchers have proposed that dysfunctioning fronto-basal ganglia circuit results in impaired grammatical processes, predicting qualitatively similar language impairments between individuals with PD and agrammatic Broca's aphasia, whereas others suggest that PD is not associated with language-specific grammatical impairment. In addition, there is a paucity of research examining syntactic production in PD at the sentence-level. This study examined sentence production of individuals with PD, healthy older adults, and individuals with agrammatic Broca's aphasia. In Experiment 1, using a Cinderella story-telling task, proportion of grammatical sentences, number of embedded clauses and production of verb arguments in sentences were examined. In Experiment 2, a structured sentence elicitation task was...

Journal of Speech, Language, and Hearing Research, 2019

Purpose Although there is increasing interest in using structural priming as a means to ameliorate grammatical encoding deficits in persons with aphasia (PWAs), little is known about the precise mechanisms of structural priming that are associated with robust and enduring effects in PWAs. Two dialogue-like comprehension-to-production priming experiments investigated whether lexically independent (abstract structural) priming and/or lexically (verb) specific priming yields immediate and longer, lasting facilitation of syntactic production in PWAs. Method Seventeen PWAs and 20 healthy older adults participated in a collaborative picture-matching task where participant and experimenter took turns describing picture cards using transitive and dative sentences. In Experiment 1, a target was elicited immediately following a prime. In Experiment 2, 2 unrelated utterances intervened between a prime and target, thereby allowing us to examine lasting priming effects. In both experiments, the ...

Lingua, 2012

Brain and language, 2009

Journal of Foreign Language Teaching and Applied Linguistics, 2016

Clinical linguistics & …, 2010

Languages

Individuals produce discourse for various purposes as part of their daily functioning. Therefore, the ability to form a discourse should be one of the main goals of functional speech-language therapy for persons with aphasia (PwA). In addition to assessing the language skills required to form a discourse, it is important to analyse how PwA form general ideas that need to be narrated. This study had two specific aims: (1) to investigate the ability of PwA, with special consideration to the stage of their recovery—the acute and the chronic phase—to form main concepts in a discourse, and (2) to examine the relationship between the number of main concepts and different types of language measures related to productivity, informativeness, and grammaticality in all tested groups. Participants included a total of 38 persons with mild and moderate aphasia (19 in the acute and 19 in the chronic phase of recovery) and 38 healthy speakers (HS) who were matched in age, gender, and level of educa...

Aphasiology, 2013

Aphasiology, 2008

The lack of standardized language assessment tools in Russian impedes clinical work, evidence-based practice, and research in Russian-speaking clinical populations. To address this gap in assessment of neurogenic language disorders, we developed and standardized a new comprehensive assessment instrument – the Russian Aphasia Test (RAT). The principal novelty of the RAT is that each subtest corresponds to a specific level of linguistic processing (phonological, lexical-semantic, syntactic, and discourse) in different domains: auditory comprehension, repetition, and oral production. In designing the test, we took into consideration various (psycho)linguistic factors known to influence language performance, as well as specific properties of Russian. The current paper describes the development of the RAT and reports its psychometric properties. A tablet-based version of the RAT was administered to 85 patients with different types and severity of aphasia and to 106 age-matched neurologic...

Aphasiology, 2010

Sentence processing requires rapid integration of information over a short period of time. Models of language processing suggest that syntactic, semantic, and phonological detail must be accessed and coordinated within milliseconds to successfully produce or understand sentences. Exactly how this is accomplished and what neural mechanisms are engaged in real time to carry out these processes is not completely understood. Research examining the neural mechanisms associated with sentence processing elucidates a left hemisphere network involving both anterior and posterior brain regions, although studies show that the right hemisphere is also engaged to some extent. This chapter discusses what is known about the neural systems involved in sentence production and comprehension. Two bodies of research are discussed: neurolinguistic evidence derived from lesion deficit studies with brain-damaged people, and neuroimaging research examining the neural correlates of sentence processing in he...

Language, Cognition and Neuroscience, 2019

PROBLEM: Traditional cognitive-linguistic therapy has demonstrated success in strengthening the semantic-lexical retrieval system through direct mapping of semantic features in persons with aphasia (PWA) (David & Thompson, 2005; Edmonds, 2014; Edmonds & Swathi, 2009). Within these treatments, auditory processing is implicitly addressed, as most practice tasks involve an auditory-verbal modality. However, evidence of explicit training of auditory processing and its effects on lexical processing is very limited. Constraint Induced Auditory Therapy (CIAT) has demonstrated the ability to strengthen the auditory input processing in some patients with aphasia; however evidence is scanty (Hurley & Davis, 2011). Also, until now there are no known studies that illustrate the combined effects of cognitive-linguistic treatment (such as Verb Network Strengthening Treatment (VNeST)) and explicit training of auditory processing (such as CIAT) on lexical retrieval and overall language ability. The...

Brain and language, 2003

Lingua, 2013

Agrammatic speakers of languages with overt grammatical case show impaired use of themorphological cues to establish theta-role relations in sentences presented in non-canonical wordorders. We analysed the effect of word order on the sentence comprehension of aphasic speakersof Basque, an ergative, free word order and head-final (SOV) language. Ergative languages such asBasque establish a one-to-one mapping of the thematic role and the case marker. We collectedbehavioural and gaze-fixation data while agrammatic speakers performed a picture-matching taskwith auditorily presented sentences with different word orders. We found that people with aphasia(PWA) had difficulties in assigning theta-roles in Theme-Agent order. This result is in line withprocessing accounts. Contrary to previous findings, our data do not suggest a systematic delay inthe integration of morphological information in the PWA group, but strong reliance on theergative case morphology and difficulties assigning thematic roles into the determiner phrases.

Clinical Linguistics & Phonetics, 2019

Agrammatic aphasia is a language disorder due to brain damage, in which grammar is particularly impaired. A core issue in neurolinguistic research is to what extent the language problems that people with aphasia suffer are exclusive to their brain damage. Possibly, the processes that are vulnerable in aphasia also require more cognitive resources for the healthy brain. A way to tap into unimpaired language processing is to study event-related potentials (ERPs) registered at the scalp. ERPs are brain responses that can be related to different levels of linguistic processing, including grammar. Also eye-movements can be used to study brain responses to language, given that gazes are drawn to objects in a closely time-locked manner with what is being heard (Cooper, 1974). In this dissertation, the neural correlates of time reference expressed by verbs were investigated in aphasic and non-brain-damaged speakers of Dutch, German, and Russian using accuracy and reaction time measures, as well as ERP and eye-tracking.Chapter 1 provided the theoretical background of the studies, leading to the research questions for the studies. Results from several structurally different languages demonstrated that agrammatic aphasic patients find it more difficult to produce and comprehend verb forms that refer to the past than verb forms that refer to the present, captured in the Past DIscourse LInking Hypothesis (PADILIH; Bastiaanse et al., 2011). The PADILIH holds that verb forms referring to the past, such as ‘wrote’, are impaired in agrammatic aphasia, because they are discourse linked: in order to interpret past time reference, an additional link has to be made to some other event time in the discourse. Verb forms referring to the present, such as ‘writes’, are relatively spared, because they are locally bound: no additional discourse- link is needed because the event time the verb refers to is in the here-and-now of the moment of speaking. The PADILIH is based on two assumptions: (1) Present tense is locally bound within the sentence and past tense is discourse linked (Zagona, 2003) and (2) Discourse linking is impaired in agrammatic aphasia, whereas local binding is intact (Avrutin, 2000). Discourse linking difficulties can also be observed in the pronominal domain (Edwards & Varlokosta, 2007; Grodzinsky et al., 1993; Ruigendijk et al., 2006) and in wh-phrases (Avrutin, 2000). In healthy speakers similar patterns can be traced (Dragoy et al., 2012; Faroqi-Shah & Dickey, 2009; Jonkers et al., 2007). This PhD project was aimed at addressing some remaining issues with respect to time reference and discourse-linking:1.Past time reference is discourse linked.2.The PADILIH applies to language use in general. 3.Past time reference difficulties are irrespective of tense.4.Processing verbs that refer to the past is delayed in agrammatism.Chapter 2 aimed to (1) investigate whether discourse-linking is the common denominator of the deficits in time reference, wh-questions, and object pronouns, and (2) to compare the comprehension of discourse- linked elements in people with agrammatic and fluent aphasia. Three sentence-picture-matching tasks were administered to 10 agrammatic, 10 fluent aphasic, and 10 non-brain-damaged Russian speakers: (1) the Test for Assessing Reference of Time (TART) for present imperfective (reference to present) and past perfective (reference to past), (2) the Wh-Extraction Assessment Tool (WHEAT) for which- and who-subject questions, and (3) the Reflexive-Pronoun Test (RePro) for reflexive and pronominal reference. Non-brain-damaged speakers scored at ceiling and significantly higher than the aphasic participants. An overall effect of discourse-linking was found in the TART and WHEAT for the agrammatic speakers, and in all three tests for the fluent speakers. Scores on the RePro were at ceiling. The results are in line with the prediction that comprehension problems of individuals with agrammatic and fluent aphasia for sentences that contain verbs with past time reference, which-question words and pronouns, are caused by the fact that these elements involve discourse linking. The effect is not specific to agrammatism, although it may result from different underlying disorders in agrammatic and fluent aphasia.Chapter 3 first aimed to untangle tense problems from problems with past time reference through verb morphology in people with aphasia. Time reference does not always coincide with tense; in languages such as Dutch and English, reference to the past can be established by using past tense (e.g., ‘he wrote a letter’) or a present tense auxiliary in combination with a participle, i.e., the present perfect (e.g., ‘he has written a letter’). The second aim of this chapter was to compare the production of time reference inflection by people with agrammatic and fluent aphasia. A sentence completion task was used to elicit reference to the non-past and past in Dutch. Reference to the past was tested through (1) a simple verb in past tense and (2) a verb complex with an auxiliary in present tense + participle (the present perfect). Reference to the non-past was tested through a simple verb in present tense. Fourteen agrammatic aphasic speakers, sixteen fluent aphasic speakers and twenty non-brain-damaged speakers took part in this study. Non-brain-damaged speakers scored at ceiling and significantly higher than the aphasic participants. Agrammatic speakers performed worse than fluent speakers, but the pattern of performance in both aphasic groups was similar. Reference to the past through past tense and [present tense auxiliary + participle] was more impaired than reference to the non-past. An error analysis revealed differences between the two groups. People with agrammatic and fluent aphasia experience problems with expressing reference to the past through verb inflection. This past time reference deficit is irrespective of the tense employed. The error patterns between the two groups reveal different underlying problems.In Chapter 4, an ERP study was presented that aimed to investigate time reference in the healthy brain. If the time frame (past, present, future) is set by a temporal adverb, the verb inflection should correspond (yesterday he walked; today he walks). Temporal violations by simple verbs (single, lexical verbs inflected with tense) in the present tense and with present time reference elicit a P600 effect (Dragoy et al., 2012; Baggio, 2008). However tense does not always coincide with time reference; in languages such as Dutch and English, reference to the past can be established by using the present tense in the present perfect (e.g., ‘he has eaten the cake’). The study in Chapter 4 investigated whether the P600 effects described by Dragoy et al. and Baggio were caused by tense or time reference violations of the verb. In the context of a past adverb, ERP responses to auxiliaries in present tense with either congruent past time reference or incongruent non-past time reference were compared. The findings showed that the P600 effect for violations of the temporal context was caused by the time reference of the complete verb form, rather than by the tense.The goal of Chapter 5 was to (1) investigate whether differences exist between non-brain-damaged individuals and agrammatic aphasic individuals in correctly processing of future and past time reference inflection, and (2) enlighten the underlying mechanism of time reference comprehension failure by agrammatic aphasic speakers. A visual-world experiment combining sentence-picture matching and eye- tracking was administered to 12 non-brain-damaged individuals and 6 agrammatic aphasic individuals, all native speakers of German. Participants heard German sentences with periphrastic future (‘will + V’) or periphrastic past (‘has + V-d’) verb forms while they were presented with pictures on a computer screen. Non-brain-damaged speakers scored at ceiling and significantly higher than the agrammatic aphasic speakers. The future condition was more difficult than the past condition for non-brain-damaged speakers (derived from response times) and agrammatic aphasic speakers (derived from response times and accuracy). However, eye movement patterns suggested a similar interpretation of future time reference in both groups, while agrammatic aphasic speakers showed a delay relative to non-brain-damaged speakers in interpretation of past time reference. The results support the PADILIH, because processing reference to the past in discourse syntax requires additional resources and, thus, is problematic and delayed for people with aphasia.Chapter 6 concluded the dissertation with a general discussion and implications. The outcomes of the research contribute to the knowledge on the influence of discourse linking on past time reference assignment, compared to non-past time reference. This dissertation sheds light on how these types of time reference are represented in the brain, how they are processed and how they can be affected by brain damage. Individuals with agrammatic aphasia often omit or substitute (past) tense inflection. The knowledge on time reference acquired within this project adds to the understanding of the underlying deficits in aphasia, which is of importance for the development of assessment and treatment methods for individuals with aphasia. Chapter 6 concludes with some directions for further research.