Word order and finiteness in Dutch and English Broca's and Wernicke's aphasia

A reconceptualization of sentence production in post-stroke agrammatic aphasia: the synergistic processing bottleneck model

The language production deficit in post-stroke agrammatic aphasia (PSA-G) tends to result from lesions to the left inferior frontal gyrus (LIFG) and is characterized by a triad of symptoms: fragmented sentences, errors in functional morphology, and a dearth of verbs. Despite decades of research, the mechanisms underlying production patterns in PSA-G have been difficult to characterize. Two major impediments to progress may have been the view that it is a purely morphosyntactic disorder and the (sometimes overzealous) application of linguistic theory without interceding psycholinguistic evidence. In this paper, empirical evidence is examined to present an integrated portrait of language production in PSA-G and to evaluate the assumption of a syntax-specific syndrome. In light of extant evidence, it is proposed that agrammatic language production results from a combination of morphosyntactic, phonomotor, and processing capacity limitations that cause a cumulative processing bottleneck at the point of articulatory planning. This proposed Synergistic Processing Bottleneck model of PSA-G presents a testable framework for future research. The paper ends with recommendations for future research on PSA-G.

Assessment of verb and sentence processing deficits in stroke-induced aphasia: the Italian version of the Northwestern Assessment of Verbs and Sentences (NAVS-I)

Background

The Northwestern Assessment of Verbs and Sentences (NAVS) assesses verb and sentence production and comprehension in aphasia. Results from the original English version and from its adaptation to German have shown that the NAVS is able to capture effects of verb-argument structure (VAS) complexity (i.e., lower accuracy for two- and three-argument vs. one-argument verbs) and syntactic complexity (i.e., lower accuracy for non-canonical vs. canonical sentences) in both agrammatic participants and individuals with mild (residual) forms of aphasia. The NAVS has been recently adapted to Italian (NAVS-I) and tested on a group of healthy participants, with results showing longer reaction times to complex vs. simple verbs and sentences.

Aims

The present study aimed to test the ability of NAVS-I to i) capture verb/sentence production and comprehension deficits in Italian-speaking individuals with agrammatism or with fluent aphasia, and ii) differentiate individuals with aphasia from healthy age-matched participants, with the overall goal to validate its use in clinical practice.

Methods & Procedures

Forty-four healthy participants and 28 individuals with aphasia (10 with agrammatic speech production) were administered the NAVS-I, which includes tasks assessing production and comprehension of verbs requiring one, two or three arguments, as well as production and comprehension of canonical and non-canonical sentences.

Outcomes & Results

On the Verb Naming Task (VNT), better production of one- (vs. two- and three-) argument verbs was found in the agrammatic group, whereas, verb production in the fluent group was solely predicted by word length and imageability. No effects of argument optionality (i.e., greater difficulty for optionally transitive verbs than for 1-argument verbs) were found. Sentence-level tasks found no differences between the agrammatic and the fluent group in production or comprehension of both canonical and non-canonical sentences; rather, sentence comprehension accuracy was predicted by demographic variables and by aphasia severity. At the individual level, performance on the NAVS-I was significantly different from that of healthy speakers in 26/28 patients.

Conclusions

Data show that the NAVS-I is able to capture effects of argument structure complexity in verb production, and effects of syntactic complexity in sentence production and comprehension. In addition, our results point to verb production as the task with greater capability to differentiate agrammatism from other (fluent) forms of aphasia. The study provides support for the use of the NAVS-I in the diagnosis of aphasia, as it is able to detect language deficits at the individual level, even in participants with mild (residual) forms of aphasia.

Processing Argument Structure and Syntactic Complexity in People with Schizophrenia Spectrum Disorders

INTRODUCTION

Deficits in language comprehension and production have been repeatedly observed in Schizophrenia Spectrum Disorders (SSD). However, the characterization of the language profile of this population is far from complete, and the relationship between language deficits, impaired thinking and cognitive functions is widely debated.

OBJECTIVE

The aims of the present study were to assess production and comprehension of verbs with different argument structures, as well as production and comprehension of sentences with canonical and non-canonical word order in people with SSD. In addition, the study investigated the relationship between language deficits and cognitive functions.

METHODS

Thirty-four participants with a diagnosis of SSD and a group of healthy control participants (HC) were recruited and evaluated using the Italian version of the Northwestern Assessment of Verbs and Sentences (NAVS, Cho-Reyes & Thompson, 2012; Barbieri et al., 2019).

RESULTS

Results showed that participants with SSD were impaired - compared to HC - on both verb and sentence production, as well as on comprehension of syntactically complex (but not simple) sentences. While verb production was equally affected by verb-argument structure complexity in both SSD and HC, sentence comprehension was disproportionately more affected by syntactic complexity in SSD than in HC. In addition, in the SSD group, verb production deficits were predicted by performance on a measure of visual attention, while sentence production and comprehension deficits were explained by performance on measures of executive functions and working memory, respectively.

DISCUSSION

Our findings support the hypothesis that language deficits in SSD may be one aspect of a more generalized, multi-domain, cognitive impairment, and are consistent with previous findings pointing to reduced inter- and intra-hemispheric connectivity as a possible substrate for such deficits. The study provides a systematic characterization of lexical and syntactic deficits in SSD and demonstrates that psycholinguistically-based assessment tools may be able to capture language deficits in this population.

Sentence Recall in Latent and Anomic Aphasia: An Exploratory Study of Semantics and Syntax

We investigated whether semantic plausibility and syntactic complexity affect immediate sentence recall in people with latent and anomic aphasia. To date, these factors have not been explored in these types of aphasia. As with previous studies of sentence recall, we measured accuracy of verbatim recall and uniquely real-time speech measures. The results showed that accuracy did not distinguish performance between latent aphasia and neurotypical controls. However, some of the real-time speech measures distinguished performance between people with latent aphasia and neurotypical controls. There was some evidence, though not pervasive, that semantic plausibility and syntactic complexity influenced recall performance. There were no interactions between semantic plausibility and syntactic complexity. The speed of preparation of responses was slower in latent aphasia than controls; it was also slower in anomic aphasia than both latent and control groups. It appears that processing speed as indexed by temporal speech measures may be differentially compromised in latent and anomic aphasia. However, semantic plausibility and syntactic complexity did not show clear patterns of performance among the groups. Notwithstanding the absence of interactions, we advance an explanation based on conceptual short-term memory as to why semantically implausible sentences are typically more erroneous and possibly also slower in recall.

Time reference, morphology and prototypicality: tense production in stroke aphasia and semantic dementia in Greek

The present study aims at investigating verb inflection in aphasia and semantic dementia. In particular, it addresses the contribution of time reference and morphological complexity. Moreover, it investigates whether the lexical properties of the verb, such as argument structure and lexical aspect interact with the production of tense. Ten individuals with (different types of) stroke aphasia and five individuals with semantic dementia and their respective control groups conducted a sentence completion task. Three tenses were tested: past perfective, past imperfective and present. All tenses had to be produced with three different verb classes, which differed with respect to syntactic and semantic properties: unergative, unaccusative and transitive verbs. The findings imply problems with marking aspect and an interaction between inflection and lexical aspect but no effect of morphological complexity or across the board difficulties with reference to the past in aphasia. Moreover, the results suggest problems with inflection in semantic dementia, an interaction between inflection and lexical aspect and a selective difficulty with imperfective tenses. The study contributes to a better understanding of inflection problems in aphasia and it provides evidence for inflection problems in semantic dementia.

Perspective-shifting are helpful for children in Chinese passive sentence comprehension

Passive sentences have been shown to be more difficult than active sentences for young children in English, German, Italian, Turkish, as well as Japanese, Korean. Many factors, such as syntactic structure, lexical-semantic, language experience, have been proved to affect passive sentence processing. In this paper, two experiments were carried out to investigate the role of perspective-shifting and animacy characteristics of agents and patients in processing passive sentences by 5~6 year-old Chinese children, using a sentence-picture matching task. The results were as follows: (1) Passive sentences were more difficult to comprehend than active sentences in Mandarin Chinese; (2) The ability of perspective-shifting played an important role in processing passive sentences. In sum, addressing sentences involving syntactic transformation is a complex cognitive activity for young children. Many factors, such as syntactic structure, lexical-semantic, language experience, and cognitive flexibility should be given full consideration.

Verb and sentence processing patterns in healthy Italian participants: Insight from the Northwestern Assessment of Verbs and Sentences (NAVS)

We developed an Italian version of the Northwestern Assessment of Verbs and Sentences (NAVS, Thompson, 2011), a test assessing verb and sentence deficits typically found in aphasia, by focusing on verb-argument structure and syntactic complexity effects, rarely captured by standard language tests. Twenty-one young healthy individuals underwent a computerized experimental version of the NAVS, including three subtests assessing production/comprehension of verbs with different number (one, two, three) and type (obligatory or optional) of arguments, and two investigating production/comprehension of sentences with canonical/non-canonical word order. The number of verb arguments affected participants' reaction times (RTs) in verb naming and comprehension. Furthermore, verbs with optional arguments were processed faster than verbs with only obligatory arguments. Comprehension accuracy was lower for object-cleft vs. subject-cleft sentences. Object clefts and object relatives also elicited longer RTs than subject clefts and subject relatives, respectively. The study shows that the NAVS is sensitive to linguistic aspects of verb/sentence processing in Italian as in the English language. The study also highlights some differences between languages in the verb/sentence processing patterns of healthy individuals. Finally, the study contributes to the understanding of how information about verb-argument structure is represented and processed in healthy individuals, with reference to current models of verb processing.

Neural encoding and production of functional morphemes in the posterior temporal lobe

Morphemes are the smallest meaning-carrying units in human language, and are among the most basic building blocks through which humans express specific ideas and concepts. By using time-resolved cortical stimulations, neural recordings, and focal lesion evaluations, we show that inhibition of a small cortical area within the left dominant posterior–superior temporal lobe selectively impairs the ability to produce appropriate functional morphemes but does not distinctly affect semantic and lexical retrieval, comprehension, or articulation. Additionally, neural recordings within this area reveal the localized encoding of morphological properties and their planned production prior to speech onset. Finally, small lesions localized to the gray matter in this area result in a selective functional morpheme-production deficit. Collectively, these findings reveal a detailed division of linguistic labor within the posterior–superior temporal lobe and suggest that functional morpheme processing constitutes an operationally discrete step in the series of computations essential to language production.

Functional morphemes allow us to express details about objects, events, and their relationships. Here, authors show that inhibiting a small cortical area within left posterior superior temporal lobe selectively impairs the ability to produce functional morphemes but does not impair other linguistic abilities.

Recovery of Online Sentence Processing in Aphasia: Eye Movement Changes Resulting From Treatment of Underlying Forms

Purpose

The present study tested whether (and how) language treatment changed online sentence processing in individuals with aphasia.

Method

Participants with aphasia (n = 10) received a 12-week program of Treatment of Underlying Forms (Thompson & Shapiro, 2005) focused on production and comprehension of passive sentences. Before and after treatment, participants performed a sentence-picture matching task with active and passive sentences as eye movements were tracked. Twelve age-matched controls also performed the task once each.

Results

In the age-matched group, eye movements indicated agent-first predictive processing after hearing the subject noun, followed by rapid thematic reanalysis after hearing the verb form. Pretreatment eye movements in the participants with aphasia showed no predictive agent-first processing, and more accurate thematic analysis in active compared to passive sentences. After treatment, which resulted in improved offline passive sentence production and comprehension, participants were more likely to respond correctly when they made agent-first eye movements early in the sentence, showed equally reliable thematic analysis in active and passive sentences, and were less likely to use a spatially based alternative response strategy.

Conclusions

These findings suggest that treatment focused on improving sentence production and comprehension supports the emergence of more normal-like sentence comprehension processes.

Recovery of Sentence Production Processes Following Language Treatment in Aphasia: Evidence from Eyetracking

Introduction: Sentence production impairments in aphasia often improve with treatment. However, little is known about how cognitive processes supporting sentence production, such as sentence planning, are impacted by treatment.

Methods: The present study used eyetracking to examine changes in sentence production resulting from a 12-week language treatment program focused on passive sentences (Treatment of Underlying Forms (TUF); Thompson and Shapiro, 2005). In two pre-treatment and two post-treatment sessions, nine participants with mild-to-moderate agrammatic aphasia performed a structural priming task, which involved repeating primed sentences (actives or passives) and then, using the same verb, producing sentences describing pictured events. Two individuals with aphasia performed the eyetracking task on the same schedule without intervening language treatment. Ten unimpaired older adults also performed the task to identify normal performance patterns. Sentence production accuracy and speech onset latencies were examined, and eye movements to the pictured Agent and Theme characters were analyzed in the first 400 ms after picture onset, reflecting early sentence planning, and in the regions preceding the production of the sentence subject and post-verbal noun, reflecting lexical encoding.

Results: Unimpaired controls performed with high accuracy. Their early eye movements (first 400 ms) indicated equal fixations to the Agent and Theme, consistent with structural sentence planning (i.e., initial construction of an abstract structural frame). Subsequent eye movements occurring prior to speech onset were consistent with encoding of the correct sentence subject (i.e., the Agent in actives, Theme in passives), with encoding of the post-verbal noun beginning at speech onset. In participants with aphasia, accuracy improved significantly with treatment, and post-treatment (but not pre-treatment) eye movements were qualitatively similar to those of unimpaired controls, indicating correct encoding of the Agent and Theme nouns for both active and passive sentences. Analysis of early eye movements also showed a treatment-induced increase in structural planning. No changes in sentence production accuracy or eye movements were found in the aphasic participants who did not receive treatment.

Conclusion: These findings indicate that treatment improves sentence production and results in the emergence of normal-like cognitive processes associated with successful sentence production, including structural planning.

Conversation Therapy with People with Aphasia and Conversation Partners using Video Feedback: A Group and Case Series Investigation of Changes in Interaction

Conversation therapies employing video for feedback and to facilitate outcome measurement are increasingly used with people with post-stroke aphasia and their conversation partners; however the evidence base for change in everyday interaction remains limited. We investigated the effect of Better Conversations with Aphasia (BCA), an intervention that is freely available online at https://extend.ucl.ac.uk/. Eight people with chronic agrammatic aphasia, and their regular conversation partners participated in the tailored 8 week program involving significant video feedback. We explored changes in: (i) conversation facilitators (such as multi-modal turns by people with aphasia); and (ii) conversation barriers (such as use of test questions by conversation partners). The outcome of intervention was evaluated directly by measuring change in video-recorded everyday conversations. The study employed a pre-post design with multiple 5 minute samples of conversation before and after intervention, scored by trained raters blind to the point of data collection. Group level analysis showed no significant increase in conversation facilitators. There was, however, a significant reduction in the number of conversation barriers. The case series data revealed variability in conversation behaviors across occasions for the same dyad and between different dyads. Specifically, post-intervention there was a significant increase in facilitator behaviors for two dyads, a decrease for one and no significant change for five dyads. There was a significant decrease in barrier behaviors for five dyads and no significant change for three dyads. The reduction in barrier behaviors was considerable; on average change from over eight to fewer than three barrier behaviors in 5 minutes of conversation. The pre-post design has the limitation of no comparison group. However, change occurs in targeted conversational behaviors and in people with chronic aphasia and their partners. The findings suggest change can occur after eight therapy sessions and have implications for clinical practice. A reduction in barrier behaviors may be easier to obtain, although the controlled case series results demonstrate a significant increase in conversation facilitators is also possible. The rehabilitation tool is available online and video technology was central to delivering intervention and evaluating change.

Tracking sentence comprehension: Test-retest reliability in people with aphasia and unimpaired adults

PURPOSE

Visual-world eyetracking is increasingly used to investigate online language processing in normal and language impaired listeners. Tracking changes in eye movements over time also may be useful for indexing language recovery in those with language impairments. Therefore, it is critical to determine the test-retest reliability of results obtained using this method.

METHODS

Unimpaired young adults and people with aphasia took part in two eyetracking sessions spaced about one week apart. In each session, participants completed a sentence-picture matching task in which they listened to active and passive sentences (e.g., The [N1+Auxwoman was] [Vvisiting/visited] [NP/PP2(by) the man]) and selected between two pictures with reversed thematic roles. We used intraclass correlations (ICCs) to examine the test-retest reliability of response measures (accuracy, reaction time (RT)) and online eye movements (i.e., the likelihood of fixating the target picture in each region of the sentence) in each participant group.

RESULTS

In the unimpaired adults, accuracy was at ceiling (thus ICCs were not computed), with moderate ICCs for RT (i.e., 0.4 - 0.58) for passive sentences and low (<0.4) for actives. In individuals with aphasia, test-retest reliability was strong (0.590.75) for RT for both sentence types. Similarly, for the unimpaired listeners, reliability of eye movements was moderate for passive sentences (NP/PP2 region) and low in all regions for active sentences. But, for the aphasic participant group, eye movement reliability was excellent for passive sentences (in the first second after sentence end) and strong for active sentences (V and NP/PP2 regions).

CONCLUSION

Results indicated moderate-to-low reliability for unimpaired listeners; however, reliable eye movement patterns were detected for processes specific to passive sentences (e.g., thematic reanalysis). In contrast, individuals with aphasia exhibited strong and stable performance across sentence types in response measures and online eye movements. These findings indicate that visual-world eyetracking provides a reliable measure of online sentence comprehension, and thus may be useful for investigating sentence processing changes over time.

Syntactic processing is distributed across the language system

Language comprehension recruits an extended set of regions in the human brain. Is syntactic processing localized to a particular region or regions within this system, or is it distributed across the entire ensemble of brain regions that support high-level linguistic processing? Evidence from aphasic patients is more consistent with the latter possibility: damage to many different language regions and to white-matter tracts connecting them has been shown to lead to similar syntactic comprehension deficits. However, brain imaging investigations of syntactic processing continue to focus on particular regions within the language system, often parts of Broca's area and regions in the posterior temporal cortex. We hypothesized that, whereas the entire language system is in fact sensitive to syntactic complexity, the effects in some regions may be difficult to detect because of the overall lower response to language stimuli. Using an individual-subjects approach to localizing the language system, shown in prior work to be more sensitive than traditional group analyses, we indeed find responses to syntactic complexity throughout this system, consistent with the findings from the neuropsychological patient literature. We speculate that such distributed nature of syntactic processing could perhaps imply that syntax is inseparable from other aspects of language comprehension (e.g., lexico-semantic processing), in line with current linguistic and psycholinguistic theories and evidence. Neuroimaging investigations of syntactic processing thus need to expand their scope to include the entire system of high-level language processing regions in order to fully understand how syntax is instantiated in the human brain.

Understanding discourse-linked elements in aphasia: a threefold study in Russian

BACKGROUND

Agrammatic speakers have problems with grammatical encoding and decoding. However, not all syntactic processes are equally problematic: present time reference, who questions, and reflexives can be processed by narrow syntax alone and are relatively spared compared to past time reference, which questions, and personal pronouns, respectively. The latter need additional access to discourse and information structures to link to their referent outside the clause (Avrutin, 2006). Linguistic processing that requires discourse-linking is difficult for agrammatic individuals: verb morphology with reference to the past is more difficult than with reference to the present (Bastiaanse et al., 2011). The same holds for which questions compared to who questions and for pronouns compared to reflexives (Avrutin, 2006). These results have been reported independently for different populations in different languages. The current study, for the first time, tested all conditions within the same population.

AIMS

We had two aims with the current study. First, we wanted to investigate whether discourse-linking is the common denominator of the deficits in time reference, wh questions, and object pronouns. Second, we aimed to compare the comprehension of discourse-linked elements in people with agrammatic and fluent aphasia.

METHODS AND PROCEDURES

Three sentence-picture-matching tasks were administered to 10 agrammatic, 10 fluent aphasic, and 10 non-brain-damaged Russian speakers (NBDs): (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.

OUTCOMES AND RESULTS

NBDs scored at ceiling and significantly higher than the aphasic participants. We found an overall effect of discourse-linking 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.

CONCLUSIONS

The results are in line with the prediction that problems that individuals with agrammatic and fluent aphasia experience when comprehending 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.

Preservation of passive constructions in a patient with primary progressive aphasia

Research into agrammatic comprehension in English has described a pattern of impaired understanding of passives and retained ability on active constructions. Some accounts of this dissociation predict that patients who are unable to comprehend actives will also be impaired in the comprehension of passives. We report the case of a man with primary progressive aphasia (PPA) (WR), whose comprehension was at chance on active sentences, but at ceiling on passives. In a series of reversible sentence comprehension tests WR displayed difficulties with active transitives and truncated actives with an auxiliary. In passive sentences, he displayed sensitivity to the agent marker by, as well as the passive morphology of the verb. This pattern of dissociation challenges current theories of agrammatic comprehension. We explore explanations based on the distinction between morphological and configurational cues, as well as on the semantic and discourse related differences between active and passive constructions.

Neural correlates of processing passive sentences

Previous research has shown that comprehension of complex sentences involving wh-movement (e.g., object-relative clauses) elicits activation in the left inferior frontal gyrus (IFG) and left posterior temporal cortex. However, relatively little is known about the neural correlates of processing passive sentences, which differ from other complex sentences in terms of representation (i.e., noun phrase (NP)-movement) and processing (i.e., the time course of syntactic reanalysis). In the present study, 27 adults (14 younger and 13 older) listened to passive and active sentences and performed a sentence-picture verification task using functional Magnetic Resonance Imaging (fMRI). Passive sentences, relative to active sentences, elicited greater activation in bilateral IFG and left temporo-occipital regions. Participant age did not significantly affect patterns of activation. Consistent with previous research, activation in left temporo-occipital cortex likely reflects thematic reanalysis processes, whereas, activation in the left IFG supports processing of complex syntax (i.e., NP-movement). Right IFG activation may reflect syntactic reanalysis processing demands associated with the sentence-picture verification task.

Sentence comprehension in Swahili-English bilingual agrammatic speakers

For this study, sentence comprehension was tested in Swahili-English bilingual agrammatic speakers. The sentences were controlled for four factors: (1) order of the arguments (base vs. derived); (2) embedding (declarative vs. relative sentences); (3) overt use of the relative pronoun "who"; (4) language (English and Swahili). Two theories were tested: the Trace Deletion Hypothesis (TDH; [Grodzinsky, Y. (1995). A restrictive theory of agrammatic comprehension. Brain and Language, 50, 27-51]) that assumes a representational deficit in agrammatic aphasia and the Derived Order Problem Hypothesis (DOP-H; Bastiaanse & Van Zonneveld, 2005), which is a processing account. Both theories have the same predictions for sentences in derived order. The difference is that the TDH predicts chance level performance for sentences in which the arguments are not in base order, whereas the DOP-H predicts poorer performance when processing demands increase. The results show that word order influences performance, in that sentences in which the arguments are in derived order are harder to comprehend than sentences in which the arguments are in base order. However, there is a significant interaction with the factor "embedding": sentences with an embedding are harder to comprehend than simple declaratives and this influence is larger in derived order sentences. There is no effect of language nor of the use of a relative pronoun. These results are correctly accounted for by the DOP-H.

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), 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.

Tracking Passive Sentence Comprehension in Agrammatic Aphasia

People with agrammatic aphasia often experience greater difficulty comprehending passive compared to active sentences. The Trace Deletion Hypothesis (TDH; Grodzinsky, 2000) proposes that aphasic individuals cannot generate accurate syntactic representations of passive sentences and, hence, use an agent-first processing strategy which leads to at-chance performance. We tested this claim using the eyetracking-while-listening paradigm in order to reveal online processing routines. Ten agrammatic aphasic participants and 10 age-matched controls listened to passive and active sentences and performed a sentence-picture matching task (i.e., selecting between two pictures with reversed thematic roles), while their eye movements were monitored. Control participants' performance was at ceiling, whereas accuracy for the aphasic participants was above chance for active sentences and at chance for passive sentences. Further, for the control participants, the eye movement data showed an initial agent-first processing bias, followed by fixation on the correct picture in the vicinity of the verb in both active and passive sentences. However, the aphasic participants showed no evidence of agent-first processing, counter the predictions of the TDH. In addition, in active sentences, they reliably fixated the correct picture only at sentence offset, reflecting slowed processing. During passive sentence processing, fixations were at chance throughout the sentence, but different patterns were noted for correct and incorrect trials. These results are consistent with the proposal that agrammatic sentence comprehension failure involves lexical processing and/or lexical integration deficits.

Dissociations Between Fluency And Agrammatism In Primary Progressive Aphasia

BACKGROUND: Classical aphasiology, based on the study of stroke sequelae, fuses speech fluency and grammatical ability. Nonfluent (Broca's) aphasia often is accompanied by agrammatism; whereas in the fluent aphasias grammatical deficits are not typical. The assumption that a similar relationship exists in primary progressive aphasia (PPA) has led to the dichotomization of this syndrome into fluent and nonfluent subtypes. AIMS: This study compared elements of fluency and grammatical production in the narrative speech of individuals with PPA to determine if they can be dissociated from one another. METHOD: Speech samples from 37 individuals with PPA, clinically assigned to agrammatic (N=11), logopenic (N=20) and semantic (N=6) subtypes, and 13 cognitively healthy control participants telling the "Cinderella Story" were analyzed for fluency (i.e., words per minute (WPM) and mean length of utterance in words (MLU-W)) and grammaticality (i.e., the proportion of grammatically correct sentences, open-to-closed-class word ratio, noun-to-verb ratio, and correct production of verb inflection, noun morphology, and verb argument structure.) Between group differences were analyzed for each variable. Correlational analyses examined the relation between WPM and each grammatical variable, and an off-line measure of sentence production. OUTCOMES AND RESULTS: Agrammatic and logopenic groups both had lower scores on the fluency measures and produced significantly fewer grammatical sentences than did semantic and control groups. However, only the agrammatic group evinced significantly impaired production of verb inflection and verb argument structure. In addition, some semantic participants showed abnormal open-to-closed and noun-to-verb ratios in narrative speech. When the sample was divided on the basis of fluency, all the agrammatic participants fell in the nonfluent category. The logopenic participants varied in fluency but those with low fluency showed variable performance on measures of grammaticality. Correlational analyses and scatter plots comparing fluency and each grammatical variable revealed dissociations within PPA participants, with some nonfluent participants showing normal grammatical skill. CONCLUSIONS: Grammatical production is a complex construct comprised of correct usage of several language components, each of which can be selectively affected by disease. This study demonstrates that individuals with PPA show dissociations between fluency and grammatical production in narrative speech. Grammatical ability, and its relationship to fluency, varies from individual to individual, and from one variant of PPA to another, and can even be found in individuals with semantic PPA in whom a fluent aphasia is usually thought to accompany preserved ability to produce grammatical utterances.

A comparison of the BAT and BDAE-SF batteries in determining the linguistic ability in Greek-speaking patients with Broca's aphasia

The aim of this study is to test the validity and reliability of the Bilingual Aphasia Test as a measure of language impairment in a Greek-speaking Broca's aphasic population and to investigate relationships with the same aphasic group's performance on the Greek version of the short form of the Boston Diagnostic Aphasia Examination battery, mainly focusing on a series of subtests which are shared by the two batteries, yet occasionally differ in content. Correlation analyses showed that the two instruments yielded highly comparable results with respect to the measurement of reading and listening comprehension, as well as in the performance-based measurement of the automated sequence capacity of the patients. Nevertheless, the Bilingual Aphasia Test, as a more extensive battery, proved to be more sensitive and objective in characterizing the patients' language abilities in a number of individual language functions, including commands, sentence repetition, naming, verbal fluency and syntactic comprehension.

Adaptation of Aphasia Tests for Neurocognitive Screening in South Africa

Two aphasia tests — the Cookie Theft Test and the Boston Naming Test — were adapted to help eliminate western cultural, language and education bias in neurocognitive screening in South Africa. These tests were among the commonly used tests initially chosen for inclusion in a larger neurocognitive screening battery currently being developed and translated for use in South Africa — the Groote Schuur Neurocognitive Battery. The adaptations were made employing quantitative and qualitative converging lines of evidence to evaluate their efficacy. This evidence included consultation with clinicians at Groote Schuur Hospital and translators knowledgeable in Afrikaans and isiXhosa language and culture, qualitative feedback from the research participants, and the results on the tests. The adapted tests were piloted by testing 30 neurocognitively intact controls consisting of equal numbers of Afrikaans, English and isiXhosa speakers, comparing their scores to their performances on the original tests. Three aphasic patients were also briefly tested. Results indicate that the adaptations made to the tests improved the performance of controls over the original versions, and tentatively suggest that the adapted tests should be able to screen for aphasia. This pilot study recommends further changes to the Groote Schuur Naming Test before its introduction into the battery ahead of its validation.

What Goes Wrong during Passive Sentence Production in Agrammatic Aphasia: An Eyetracking Study

BACKGROUND: Production of passive sentences is often impaired in agrammatic aphasia and has been attributed both to an underlying structural impairment (e.g., Schwartz, Saffran, Fink, Myers, & Martin, 1994) and to a morphological deficit (e.g., Caplan & Hanna, 1998; Faroqi-Shah & Thompson, 2003). However, the nature of the deficit in passive sentence production is not clear due to methodological issues present in previous studies. AIMS: This study examined active and passive sentence production in nine agrammatic aphasic speakers under conditions of structural priming using eyetracking to test whether structural impairments occur independently of morphological impairments and whether the underlying nature of error types is reflected in on-line measures, i.e., eye movements and speech onset latencies. METHODS #ENTITYSTARTX00026; PROCEDURES: Nine participants viewed and listened to a prime sentence in either active or passive voice, and then repeated it aloud. Next, a target picture appeared on the computer monitor and participants were instructed to describe it using the primed sentence structure. OUTCOMES #ENTITYSTARTX00026; RESULTS: Participants made substantial errors in sentence structure, i.e., passives with role reversals (RRs) and actives-for-passives, but few errors in passive morphology. Longer gaze durations to the first-produced noun for passives with RRs as compared to correct passives were found before and during speech. For actives-for-passives, however, this pattern was found during speech, but not before speech. CONCLUSIONS: The deficit in passive sentence production does not solely arise from a morphological deficit, rather it stems, at least in part, from a structural level impairment. The underlying nature of passives with RRs is qualitatively different from that of actives-for-passives, which cannot be clearly differentiated with off-line testing methodology.

Culture and neuroscience: additive or synergistic?

The investigation of cultural phenomena using neuroscientific methods-cultural neuroscience (CN)-is receiving increasing attention. Yet it is unclear whether the integration of cultural study and neuroscience is merely additive, providing additional evidence of neural plasticity in the human brain, or truly synergistic, yielding discoveries that neither discipline could have achieved alone. We discuss how the parent fields to CN: cross-cultural psychology, psychological anthropology and cognitive neuroscience inform the investigation of the role of cultural experience in shaping the brain. Drawing on well-established methodologies from cross-cultural psychology and cognitive neuroscience, we outline a set of guidelines for CN, evaluate 17 CN studies in terms of these guidelines, and provide a summary table of our results. We conclude that the combination of culture and neuroscience is both additive and synergistic; while some CN methodologies and findings will represent the direct union of information from parent fields, CN studies employing the methodological rigor required by this logistically challenging new field have the potential to transform existing methodologies and produce unique findings.

Linguistic complexity and frequency in agrammatic speech production

There is a long standing debate between aphasiologists on the essential factor that constitutes the behavioral patterns of loss and preservation in agrammatic Broca's aphasia. It has been suggested that linguistic complexity plays a crucial role: linguistically complex structures are more difficult to produce than linguistically simple ones. However, linguistic complex structures are often less frequent in a language; for example, simple active sentences are more frequently used than linguistically more complex passive sentences. Hence, it might be that it is not linguistic complexity but frequency that determines agrammatic behavior. Frequency may play a role at several levels. For agrammatic patients, for example, the frequency of sentence constructions may be crucial, whereas for fluent aphasic speakers word frequency influences performance. The present study presents corpus frequency data for constructions that have previously been used to show the influence of linguistic complexity on Dutch agrammatic speech production. These are data on: (1) verb movement; (2) object scrambling; and (3) verbs with alternating transitivity. We compared the data of our corpus research with the performance of agrammatic speakers on the constructions. The conclusion is that frequency cannot account for the data, but linguistic complexity can. It is then discussed what 'linguistic complexity' exactly stands for, in terms of the word order deficit in agrammatic aphasia.

Processing of wh-questions in a case of posterior cortical atrophy

Posterior cortical atrophy (PCA) is a type of dementia that is characterized by visuo-spatial and memory deficits, dyslexia and dysgraphia, relatively early onset and preserved insight. Language deficits have been reported in some cases of PCA. Using an off-line grammaticality judgement task, processing of wh-questions is investigated in a case of PCA. Other aspects of auditory language are also reported. It is shown that processing of wh-questions is influenced by syntactic structure, a novel finding in this condition. The results are discussed with reference to accounts of wh-questions in aphasia. An uneven profile of other language abilities is reported with deficits in digit span (forward, backward), story retelling ability, comparative questions but intact abilities in following commands, repetition, concept definition, generative naming and discourse comprehension.

Verb and sentence processing in Norwegian aphasic speakers compared to Dutch and English aphasic speakers: experimental evidence

The article reports on a comparative study of the abilities of aphasic speakers and normal control subjects to comprehend and produce verbs and sentences. The analysis is based on test results obtained as part of the standardization procedure for a test battery originally developed for Dutch and since translated and adapted for English and Norwegian. With a few exceptions, there is extensive similarity in the test results between the different languages. The exceptions can be accounted for with reference both to structural differences between the languages and to coincidental aspects of informant selection and scoring procedures. The Norwegian version contains an additional sub-test on past tense inflection, which correlates significantly with at least two other sub-tests in the test battery.

Comprehension of passives in Broca's aphasia

Drai and Grodzinsky have statistically analyzed a large corpus of data on the comprehension of passives by patients with Broca's aphasia. The data come, according to Drai and Grodzinsky, from binary choice tasks. Among the languages that are analyzed are Dutch and German. Drai and Grodzinsky argue that Dutch and German speaking Broca patients should be relatively good (that is, perform above chance) on comprehension of passive sentences, since in Dutch and German passives the relative order of the object and lexical verb is the underlying order and hence no movement takes place. We will demonstrate that both their linguistic arguments and their selection of Dutch data are invalid.