The role of syntactic complexity in treatment of sentence deficits in agrammatic aphasia: the complexity account of treatment efficacy (CATE)

Evaluating Treatment and Generalization Patterns of Two Theoretically Motivated Sentence Comprehension Therapies

Purpose

The current study examined treatment outcomes and generalization patterns following 2 sentence comprehension therapies: object manipulation (OM) and sentence-to-picture matching (SPM). Findings were interpreted within the framework of specific deficit and resource reduction accounts, which were extended in order to examine the nature of generalization following treatment of sentence comprehension deficits in aphasia.

Method

Forty-eight individuals with aphasia were enrolled in 1 of 8 potential treatment assignments that varied by task (OM, SPM), complexity of trained sentences (complex, simple), and syntactic movement (noun phrase, wh-movement). Comprehension of trained and untrained sentences was probed before and after treatment using stimuli that differed from the treatment stimuli.

Results

Linear mixed-model analyses demonstrated that, although both OM and SPM treatments were effective, OM resulted in greater improvement than SPM. Analyses of covariance revealed main effects of complexity in generalization; generalization from complex to simple linguistically related sentences was observed both across task and across movement.

Conclusions

Results are consistent with the complexity account of treatment efficacy, as generalization effects were consistently observed from complex to simpler structures. Furthermore, results provide support for resource reduction accounts that suggest that generalization can extend across linguistic boundaries, such as across movement type.

Treatment of sentence comprehension and production in aphasia: is there cross-modal generalisation?

Exploring generalisation following treatment of language deficits in aphasia can provide insights into the functional relation of the cognitive processing systems involved. In the present study, we first review treatment outcomes of interventions targeting sentence processing deficits and, second report a treatment study examining the occurrence of practice effects and generalisation in sentence comprehension and production. In order to explore the potential linkage between processing systems involved in comprehending and producing sentences, we investigated whether improvements generalise within (i.e., uni-modal generalisation in comprehension or in production) and/or across modalities (i.e., cross-modal generalisation from comprehension to production or vice versa). Two individuals with aphasia displaying co-occurring deficits in sentence comprehension and production were trained on complex, non-canonical sentences in both modalities. Two evidence-based treatment protocols were applied in a crossover intervention study with sequence of treatment phases being randomly allocated. Both participants benefited significantly from treatment, leading to uni-modal generalisation in both comprehension and production. However, cross-modal generalisation did not occur. The magnitude of uni-modal generalisation in sentence production was related to participants' sentence comprehension performance prior to treatment. These findings support the assumption of modality-specific sub-systems for sentence comprehension and production, being linked uni-directionally from comprehension to production.

Implicit learning and implicit treatment outcomes in individuals with aphasia

BACKGROUND

Implicit learning is a process of learning that occurs outside of conscious awareness and may be involved in implicit, exposure-based language training. However, research shows that implicit learning abilities are variable among individuals with aphasia, and it remains unknown whether individuals who show basic implicit learning abilities also benefit from implicit language training.

AIMS

The aims of this series of experiments were to test implicit learning in individuals with agrammatic aphasia, examine the effects of a novel implicit language treatment, and investigate whether individuals with aphasia who show implicit learning ability also benefit from implicit treatment focused on passive sentence comprehension.

METHODS & PROCEDURES

Nine participants with chronic agrammatic aphasia and 21 neurologically intact participants completed a visuomotor serial reaction time test of implicit learning (Experiment 1). The participants with aphasia also completed a short-term novel implicit sentence comprehension treatment (Experiment 2) that consisted of five sessions of repeated exposure to grammatically correct passive sentences and matching photographs. Sentence comprehension was tested in multiple baseline sessions and on each day of training using a sentence-picture matching task. The relation between participants' learning patterns across experiments was also examined.

OUTCOMES & RESULTS

Individuals with agrammatic aphasia as well as neurologically intact adults demonstrated significant implicit sequence learning in the serial reaction time task. However, the participants with aphasia did not show concomitant improvement in sentence comprehension as a result of the implicit treatment protocol.

CONCLUSIONS

This study suggests that individuals with agrammatic aphasia demonstrate implicit learning ability; however, this ability does not necessarily promote successful outcomes in treatment that is based solely on implicit training methods.

Comparing the production of complex sentences in Persian patients with post-stroke aphasia and non-damaged people with normal speaking

BACKGROUND

Cerebrovascular disease leading to stroke is the most common cause of aphasia. Speakers with agrammatic non-fluent aphasia have difficulties in production of movement-derived sentences such as passive sentences, topicalized constituents, and Wh-questions. To assess the production of complex sentences, some passive, topicalized and focused sentences were designed for patients with non-fluent Persian aphasic. Afterwards, patients' performance in sentence production was tested and compared with healthy non-damaged subjects.

METHODS

In this cross sectional study, a task was designed to assess the different types of sentences (active, passive, topicalized and focused) adapted to Persian structures. Seven Persian patients with post-stroke non-fluent agrammatic aphasia (5 men and 2 women) and seven healthy non-damaged subjects participated in this study. The computed tomography (CT) scan or magnetic resonance imaging (MRI) showed that all the patients had a single left hemisphere lesion involved middle cerebral artery (MCA), Broca`s area and in its white matter. In addition, based on Bedside version of Persian Western Aphasia Battery (P-WAB-1), all of them were diagnosed with moderate Broca aphasia. Then, the production task of Persian complex sentences was administered.

RESULTS

There was a significant difference between four types of sentences in patients with aphasia [Degree of freedom (df) = 3, P < 0.001]. All the patients showed worse performance than the healthy participants in all the four types of sentence production (P < 0.050).

CONCLUSION

In general, it is concluded that topicalized and focused sentences as non-canonical complex sentences in Persian are very difficult to produce for patients with agrammatic non-fluent aphasia. It seems that sentences with A-movement are simpler for the patients than sentences involving A`-movement; since they include shorter movements in compare to topicalized and focused sentences.

Amphetamine and other pharmacological agents in human and animal studies of recovery from stroke

Neuromodulation with pharmacological agents, including drugs of abuse such as amphetamine, when paired with behavioral experience, has been shown to positively modify outcomes in animal models of stroke. A number of clinical studies have tested the efficacy of a variety of drugs to enhance recovery of language deficit post-stroke. The purpose of this paper is to: (1) present pertinent animal studies supporting the use of dextro-amphetamine sulfate (AMPH) to enhance recovery after experimental lesions with emphasis on the importance of learning dependent activity for lasting recovery; (2) briefly review neuropharmacological explorations in the treatment of aphasia; (3) present a pilot study in aphasia exploring a drug combination of AMPH and donepezil hydrochloride paired with behavioral treatment to facilitate recovery; and (4) conclude with comments regarding the role of adjunctive pharmacotherapy in the rehabilitation of aphasia, particularly AMPH.

Morphological cues in the comprehension of relative clauses by Greek children with specific language impairment and typical development: A comparative study

PURPOSE

This study investigated the effect of morphological case and number marking on the comprehension of relative clauses by Greek children with Specific Language Impairment and Language Age controls.

METHOD

An agent selection task and experimental materials consisting of 12 subject and 12 object relative clauses were employed. There were two experimental conditions: The first one manipulated number marking for Noun Phrases and the verb (singular vs plural) and neutralised Case through the use of Noun Phrases with neuter gender, which in Greek is ambiguous between Nominative and Accusative. The second one manipulated case and included Noun Phrases marked for morphological case.

RESULT

The Language Age controls performed better on the comprehension of object relative clauses with case manipulation than on those with number, unlike the children with Specific Language Impairment, who performed at the same level on the comprehension of relative clauses with number and case manipulation.

CONCLUSION

The children with Specific Language Impairment did not make efficient use of the morphological case cues in object relative clause interpretation. We argue that deficient use of case cues in object relative clause interpretation is due to difficulties in rapid interpretation of case information in these demanding structures.

Changes in functional connectivity related to direct training and generalization effects of a word finding treatment in chronic aphasia

The neural mechanisms that underlie generalization of treatment-induced improvements in word finding in persons with aphasia (PWA) are currently poorly understood. This study aimed to shed light on changes in functional network connectivity underlying generalization in aphasia. To this end, we used fMRI and graph theoretic analyses to examine changes in functional connectivity after a theoretically-based word-finding treatment in which abstract words were used as training items with the goal of promoting generalization to concrete words. Ten right-handed native English-speaking PWA (7 male, 3 female) ranging in age from 47 to 75 (mean=59) participated in this study. Direct training effects coincided with increased functional connectivity for regions involved in abstract word processing. Generalization effects coincided with increased functional connectivity for regions involved in concrete word processing. Importantly, similarities between training and generalization effects were noted as were differences between participants who generalized and those who did not.

Can tDCS enhance item-specific effects and generalization after linguistically motivated aphasia therapy for verbs?

BACKGROUND

Aphasia therapy focusing on abstract properties of language promotes both item-specific effects and generalization to untreated materials. Neuromodulation with transcranial Direct Current Stimulation (tDCS) has been shown to enhance item-specific improvement, but its potential to enhance generalization has not been systematically investigated. Here, we test the efficacy of ACTION (a linguistically motivated protocol) and tDCS in producing item-specific and generalized improvement in aphasia.

METHOD

Nine individuals with post-stroke aphasia participated in this study. Participants were pre-tested with a diagnostic language battery and a cognitive screening. Experimental tasks were administered over multiple baselines. Production of infinitives, of finite verbs and of full sentences were assessed before and after each treatment phase. Nonword repetition was used as a control measure. Each subject was treated in two phases. Ten daily 1-h treatment sessions were provided per phase, in a double-blind, cross-over design. Linguistically-motivated language therapy focusing on verb inflection and sentence construction was provided in both phases. Each session began with 20 min of real or sham tDCS. Stimulation site was determined individually, based on MRI scans.

RESULTS

Group data showed improved production of treated and untreated verbs, attesting the efficacy of behavioral treatment, and its potential to yield generalization. Each individual showed significant item-specific improvement. Generalization occurred in the first phase of treatment for all subjects, and in the second phase for two subjects. Stimulation effects at the group level were significant for treated and untreated verbs altogether, but a ceiling effect for Sham cannot be excluded, as scores between real tDCS and Sham differed only before treatment.

CONCLUSION

Our data demonstrate the efficacy of ACTION and suggest that tDCS may enhance both item-specific effects and generalization.

The Influence of Phonomotor Treatment on Word Retrieval Abilities in 26 Individuals With Chronic Aphasia: An Open Trial

PURPOSE

The ultimate goal of aphasia therapy should be to achieve gains in function that generalize to untrained exemplars and daily conversation. Anomia is one of the most disabling features of aphasia. The predominantly lexical/semantic approaches used to treat anomia have low potential for generalization due to the orthogonality of semantic and phonologic representations; this has been borne out in a meta-analysis of treatment studies. The intensive, neurally distributed, phonologic therapy reported here can, in principle, generalize to untrained phonologic sequences because of extant regularities in phonologic sequence knowledge and should, in principle, generalize to production of words trained as well as those untrained.

METHOD

Twenty-six persons with chronic aphasia due to stroke were treated, in a staggered (immediate vs. delayed treatment) open trial design, with 60 hr of intensive, multimodal therapy designed to enhance access to and efficiency of phonemes and phonologic sequences.

RESULTS

There was an absolute increase of 5% in confrontation naming of "untrained" nouns at 3 months, and there were 9% to 10% increases on measures of generalization of phonologic processes.

CONCLUSION

The results of this trial demonstrate generalization of training effects on laboratory measures, which were sustained at 3 months, and provide support for the theories that motivated the treatment.

Training Pseudoword Reading in Acquired Dyslexia: A Phonological Complexity Approach

BACKGROUND

Individuals with acquired phonological dyslexia experience difficulty associating written letters with corresponding sounds, especially in pseudowords. Previous studies have shown that reading can be improved in these individuals by training letter-sound correspondence, practicing phonological skills, or using combined approaches. However, generalization to untrained items is typically limited.

AIMS

We investigated whether principles of phonological complexity can be applied to training letter-sound correspondence reading in acquired phonological dyslexia to improve generalization to untrained words. Based on previous work in other linguistic domains, we hypothesized that training phonologically "more complex" material (i.e., consonant clusters with small sonority differences) would result in generalization to phonologically "less complex" material (i.e., consonant clusters with larger sonority differences), but this generalization pattern would not be demonstrated when training the "less complex" material.

METHODS & PROCEDURES

We used a single-participant, multiple baseline design across participants and behaviors to examine phonological complexity as a training variable in five individuals. Based on participants' error data from a previous experiment, a "more complex" onset and a "less complex" onset were selected for training for each participant. Training order assignment was pseudo-randomized and counterbalanced across participants. Three participants were trained in the "more complex" condition and two in the "less complex" condition while tracking oral reading accuracy of both onsets.

OUTCOMES & RESULTS

As predicted, participants trained in the "more complex" condition demonstrated improved pseudoword reading of the trained cluster and generalization to pseudowords with the untrained, "simple" onset, but not vice versa.

CONCLUSIONS

These findings suggest phonological complexity can be used to improve generalization to untrained phonologically related words in acquired phonological dyslexia. These findings also provide preliminary support for using phonological complexity theory as a tool for designing more effective and efficient reading treatments for acquired dyslexia.

Speech and swallow rehabilitation following partial glossectomy: a systematic review

PURPOSE

Tongue cancer is known to negatively affect both speech and swallowing function; however this is the first review to report speech-language pathology (SLP) intervention for both functions following partial glossectomy.

METHOD

Using a PRISMA approach, systematic screening of nine databases was undertaken. Original studies reporting SLP rehabilitation for speech and/or swallowing dysfunction with participants following partial glossectomy as primary cancer treatment were included.

RESULT

These studies are discussed in terms of SLP assessment and intervention trends as well as quality according to current research method standards (levels of evidence, Pedro-P, SCED) in order to determine suitability for guiding current clinical practice.

CONCLUSION

Publications were few (n = 7) and mostly of non-experimental design. This review highlights the gap in evidence and questions the rationale of current SLP rehabilitation following partial glossectomy.

Training-induced improvement of noncanonical sentence production does not generalize to comprehension: evidence for modality-specific processes

The presence or absence of generalization after treatment can provide important insights into the functional relationship between cognitive processes. The aim of the present study was to investigate the relationship between the cognitive processes that underlie sentence comprehension and production in aphasia. Using data from seven participants who took part in a case-series intervention study that focused on noncanonical sentence production [Stadie et al. (2008). Unambiguous generalization effects after treatment of noncanonical sentence production in German agrammatism. Brain and Language, 104, 211-229], we identified patterns of impairments and generalization effects for the two modalities. Results showed (a) dissociations between sentence structures and modalities before treatment, (b) an absence of cross-modal generalization from production to comprehension after treatment, and (c), a co-occurrence of spared comprehension before treatment and generalization across sentence structures within production after treatment. These findings are in line with the assumption of modality-specific, but interacting, cognitive processes in sentence comprehension and production. More specifically, this interaction is assumed to be unidirectional, allowing treatment-induced improvements in production to be supported by preserved comprehension.

A Systematic Review on methods of evaluate sentence production deficits in agrammatic aphasia patients: Validity and Reliability issues

BACKGROUND

The grammar assessment in aphasia has been done by few standard tests, but today these tests cannot precise evaluate the sentence production in agrammatic patients. In this study, we review structures and contents of tests or tasks designed to find more frequent methods for sentence production ability in aphasia patients.

MATERIALS AND METHODS

We searched the Cochrane library, Medline by PubMed, Science Direct, Scopus, and Google Scholar from 1980 to October 1, 2013 and evaluated all of exist tests or tasks included in the articles and systematic reviews. The sentence production has been studied in three methods. It contains the use of sentence production in spontaneous speech, tasks designed and both methods. The quality of studies was assessed using Critical Appraisal Skills Program.

RESULTS

The 160 articles were reviewed and 38 articles were studied according to inclusion and exclusion criteria. They were classified into three categories based on assessment methods of sentence production. In 39.5% studies, researchers have used tasks designed, 7.9% articles have applied spontaneous speech and 52.6% articles have used both methods for evaluation production. Inter-rater reliability was between 90% and 100% and intra-rater reliability was between 96% and 98% in studied.

CONCLUSION

Agrammatic aphasia has syntax disorders, especially in sentence production. Most researchers and clinicians used both methods for evaluation production.

Contextual Constraint Treatment for coarse coding deficit in adults with right hemisphere brain damage: generalisation to narrative discourse comprehension

Coarse coding is the activation of broad semantic fields that can include multiple word meanings and a variety of features, including those peripheral to a word's core meaning. It is a partially domain-general process related to general discourse comprehension and contributes to both literal and non-literal language processing. Adults with damage to the right cerebral hemisphere (RHD) and a coarse coding deficit are particularly slow to activate features of words that are relatively distant or peripheral. This manuscript reports a pre-efficacy study of Contextual Constraint Treatment (CCT), a novel, implicit treatment designed to increase the efficiency of coarse coding with the goal of improving narrative comprehension and other language performance that relies on coarse coding. Participants were four adults with RHD. The study used a single-subject controlled experimental design across subjects and behaviours. The treatment involved pre-stimulation, using a hierarchy of strong and moderately biased contexts, to prime the intended distantly related features of critical stimulus words. Three of the four participants exhibited gains in auditory narrative discourse comprehension, the primary outcome measure. All participants exhibited generalisation to untreated items. No strong generalisation to processing non-literal language was evident. The results indicate that CCT yields both improved efficiency of the coarse coding process and generalisation to narrative comprehension.

How justice can affect jury: training abstract words promotes generalisation to concrete words in patients with aphasia

Developing language treatments that not only improve trained items but also promote generalisation to untrained items is a major focus in aphasia research. This study is a replication and extension of previous work which found that training abstract words in a particular context-category promotes generalisation to concrete words but not vice versa (Kiran, Sandberg, & Abbott, 2009 ). Twelve persons with aphasia (five female) with varying types and degrees of severity participated in a generative naming treatment based on the Complexity Account of Treatment Efficacy (CATE; Thompson, Shapiro, Kiran, & Sobecks, 2003 ). All participants were trained to generate abstract words in a particular context-category by analysing the semantic features of the target words. Two other context-categories were used as controls. Ten of the twelve participants improved on the trained abstract words in the trained context-category. Eight of the ten participants who responded to treatment also generalised to concrete words in the same context-category. These results suggest that this treatment is both efficacious and efficient. We discuss possible mechanisms of training and generalisation effects.

Integrated training for aphasia: an application of part-whole learning to treat lexical retrieval, sentence production, and discourse-level communications in three cases of nonfluent aphasia

PURPOSE

The purpose of this study was to evaluate integrated training for aphasia (ITA), a multicomponent language-production treatment based on part-whole learning that systematically trains lexical retrieval, sentence production, and discourse-level communications. Specific research objectives were to evaluate acquisition of target structures, statistical parameters associated with learning variables, treatment generalization, and the efficacy of individual treatment components.

METHOD

ITA was administered to 3 individuals with nonfluent aphasia following a multiple-baseline, across-behaviors design. Effect size and correlational coefficients were computed to assess acquisition, generalization, and maintenance of target structures. Standardized tests and a treatment efficacy questionnaire were also completed.

RESULTS

A significant treatment effect was found in 2 of the 3 participants. In addition, as is seen in normal skill acquisition, practice time and error rate were significantly correlated. All participants demonstrated evidence of generalization on standardized language measures. Only 1 participant improved, however, on the communication measures. Results of the treatment component analysis revealed significant differences in the perceived efficacy of individual therapy tasks.

CONCLUSIONS

Findings add to the evidence supporting multicomponent aphasia treatments, provide preliminary support for ITA and the application of a part-whole learning approach, and suggest that specific treatment components may contribute differentially to outcomes and generalization effects.

Psycholinguistics of Aphasia Pharmacotherapy: Asking the Right Questions

BACKGROUND

Among the obstacles to demonstrating efficacy of pharmacological intervention for aphasia is quantifying patients' responses to treatment in a statistically valid and reliable manner. In many of the review papers on this topic (e.g., Berthier et al., 2011; de Boissezon, Peran, de Boysson, & Démonet, 2007; Small & Llano, 2009), detailed discussions of various methodological problems are highlighted, with some suggestions on how these shortcomings should be addressed. Given this deep understanding of caveats associated with the experimental design of aphasia pharmacotherapy studies (e.g., Berthier et al., 2011), investigations continue to produce inconsistent results.

AIM

In this review paper we suggest that inclusion of theory-driven linguistic measures in aphasia pharmacotherapy studies would add an important step toward elucidating precise patterns of improvement in language performance resulting from pharmacotherapeutic intervention.

MAIN CONTRIBUTION

We provide a brief review of the clinical approaches currently used in pharmacotherapy studies of aphasia, which often lack psycholinguistic grounding. We then present ways in which psycholinguistic models can complement this approach, offering a rationale for task selection, and as a result, lead to a better understanding of treatment effects. We then follow with an example of how such an integrative approach can be implemented in studies targeting stress reduction in people with aphasia, via beta-blocking agents, as a means to augment language performance, using the psycholinguistic framework of "linguistic anxiety" outlined in Cahana-Amitay et al, 2011 as our guideline.

CONCLUSION

We conclude that the incorporation of psycholinguistic models into aphasia pharmacotherapy studies can increase the resolution with which we can identify functional changes.

Reading and listening in people with aphasia: effects of syntactic complexity

PURPOSE

The purpose of this study was to compare online effects of syntactic complexity in written and spoken sentence comprehension in people with aphasia (PWA) and adults with no brain damage (NBD).

METHOD

The participants in Experiment 1 were NBD older and younger adults (n = 20 per group). The participants in Experiment 2 were 10 PWA. In both experiments, the participants read and listened to sentences in self-paced reading and listening tasks. The experimental materials consisted of object cleft sentences (e.g., It was the girl who the boy hugged.) and subject cleft sentences (e.g., It was the boy who hugged the girl.).

RESULTS

The predicted effects of syntactic complexity were observed in both Experiments 1 and 2: Reading and listening times were longer for the verb in sentences with object compared to subject relative clauses. The NBD controls showed exaggerated effects of syntactic complexity in reading compared to listening. The PWA did not show different modality effects from the NBD participants.

CONCLUSION

Although effects of syntactic complexity were somewhat exaggerated in reading compared with listening, both the PWA and the NBD controls showed similar effects in both modalities.

Training verb argument structure production in agrammatic aphasia: behavioral and neural recovery patterns

INTRODUCTION

Neuroimaging and lesion studies indicate a left hemisphere network for verb and verb argument structure processing, involving both frontal and temporoparietal brain regions. Although their verb comprehension is generally unimpaired, it is well known that individuals with agrammatic aphasia often present with verb production deficits, characterized by an argument structure complexity hierarchy, indicating faulty access to argument structure representations for production and integration into syntactic contexts. Recovery of verb processing in agrammatism, however, has received little attention and no studies have examined the neural mechanisms associated with improved verb and argument structure processing. In the present study we trained agrammatic individuals on verbs with complex argument structure in sentence contexts and examined generalization to verbs with less complex argument structure. The neural substrates of improved verb production were examined using functional magnetic resonance imaging (fMRI).

METHODS

Eight individuals with chronic agrammatic aphasia participated in the study (four experimental and four control participants). Production of three-argument verbs in active sentences was trained using a sentence generation task emphasizing the verb's argument structure and the thematic roles of sentential noun phrases. Before and after training, production of trained and untrained verbs was tested in naming and sentence production and fMRI scans were obtained, using an action naming task.

RESULTS

Significant pre- to post-training improvement in trained and untrained (one- and two-argument) verbs was found for treated, but not control, participants, with between-group differences found for verb naming, production of verbs in sentences, and production of argument structure. fMRI activation derived from post-treatment compared to pre-treatment scans revealed upregulation in cortical regions implicated for verb and argument structure processing in healthy controls.

CONCLUSIONS

Training verb deficits emphasizing argument structure and thematic role mapping is effective for improving verb and sentence production and results in recruitment of neural networks engaged for verb and argument structure processing in healthy individuals.

For a new look at 'lexical errors': evidence from semantic approximations with verbs in aphasia

The ability to understand the similarity between two phenomena is fundamental for humans. Designated by the term analogy in psychology, this ability plays a role in the categorization of phenomena in the world and in the organisation of the linguistic system. The use of analogy in language often results in non-standard utterances, particularly in speakers with aphasia. These non-standard utterances are almost always studied in a nominal context and considered as errors. We propose a study of the verbal lexicon and present findings that measure, by an action-video naming task, the importance of verb-based non-standard utterances made by 17 speakers with aphasia ("la dame déshabille l'orange"/the lady undresses the orange, "elle casse la tomate"/she breaks the tomato). The first results we have obtained allow us to consider these type of utterances from a new perspective: we propose to eliminate the label of "error", suggesting that they may be viewed as semantic approximations based upon a relationship of inter-domain synonymy and are ingrained in the heart of the lexical system.

Neuroimaging in aphasia treatment research: consensus and practical guidelines for data analysis

Functional magnetic resonance imaging is the most widely used imaging technique to study treatment-induced recovery in post-stroke aphasia. The longitudinal design of such studies adds to the challenges researchers face when studying patient populations with brain damage in cross-sectional settings. The present review focuses on issues specifically relevant to neuroimaging data analysis in aphasia treatment research identified in discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). In particular, we aim to provide the reader with a critical review of unique problems related to the pre-processing, statistical modeling and interpretation of such data sets. Despite the fact that data analysis procedures critically depend on specific design features of a given study, we aim to discuss and communicate a basic set of practical guidelines that should be applicable to a wide range of studies and useful as a reference for researchers pursuing this line of research.

Neuroimaging in aphasia treatment research: consensus and practical guidelines for data analysis

Functional magnetic resonance imaging is the most widely used imaging technique to study treatment-induced recovery in post-stroke aphasia. The longitudinal design of such studies adds to the challenges researchers face when studying patient populations with brain damage in cross-sectional settings. The present review focuses on issues specifically relevant to neuroimaging data analysis in aphasia treatment research identified in discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). In particular, we aim to provide the reader with a critical review of unique problems related to the pre-processing, statistical modeling and interpretation of such data sets. Despite the fact that data analysis procedures critically depend on specific design features of a given study, we aim to discuss and communicate a basic set of practical guidelines that should be applicable to a wide range of studies and useful as a reference for researchers pursuing this line of research.

Nonlinguistic learning in individuals with aphasia: effects of training method and stimulus characteristics

PURPOSE

The purpose of the current study was to explore nonlinguistic learning ability in individuals with aphasia, examining the impact of stimulus typicality and feedback on success with learning.

METHOD

Eighteen individuals with aphasia and 8 nonaphasic controls participated in this study. All participants completed 4 computerized, nonlinguistic category-learning tasks. Learning ability was probed under 2 methods of instruction: feedback-based (FB) and paired-associate (PA). The impact of task complexity on learning ability was also examined, comparing 2 stimulus conditions: typical and atypical. Performance was compared between groups and across conditions.

RESULTS

The controls were able to successfully learn categories under all conditions. For the individuals with aphasia, 2 patterns of performance arose: One subgroup of individuals was able to maintain learning across task manipulations and conditions; the other subgroup demonstrated a sensitivity to task complexity, learning successfully only in the typical training conditions.

CONCLUSION

Results support the hypothesis that impairments of general learning are present in individuals with aphasia. Some individuals demonstrated the ability to extract category information under complex training conditions; others learned only under conditions that were simplified and that emphasized salient category features. Overall, the typical training condition facilitated learning for all of the participants. Findings have implications for treatment, which are discussed.

The role of commonality, distinctiveness and importance of semantic features in persons with aphasia

OBJECTIVE

Semantic feature approaches are frequently included in treatment for people with aphasia. The present study investigated the role of distinctiveness and importance in the semantic feature knowledge of people with aphasia. The relationships between feature knowledge and the ability to choose among semantically-related foils, comprehension and naming abilities were examined.

METHODS

Participants distinguished target nouns from related foils and completed a sorting task involving mid-importance common (MIC), mid-importance distinctive (MID), low-importance common (LIC) and low-importance distinctive (LID) features. Participants also completed sub-tests from the short version of the Boston Diagnostic Aphasia Examination-Third Edition (BDAE-3) and Boston Naming Test-Second Edition (BNT-2). Participants were divided into two groups based on ability to accurately select target nouns from semantically-related foils.

RESULTS

Group 1, participants with intact ability to choose among related foils, was significantly less impaired with the identification of distinctive features than Group 2, those with difficulty choosing among related foils. Importance was not a significant factor when comparing mid-importance to low-importance features.

CONCLUSIONS

These results suggest that distinctive feature knowledge contributes in a significant way to the integrity of semantic representations in people with aphasia which can influence their performance of language tasks.

Activating situation schemas: the effects of multiple thematic roles on related verbs in a continuous priming paradigm

Extensive evidence has shown that presentation of a word (target) following a related word (prime) results in faster reaction times compared to unrelated words. Two primes preceding a target have been used to examine the effects of multiple influences on a target. Several studies have observed greater, or additive, priming effects of multiple related primes compared to single related primes. The present study aims to eliminate attentional factors that may have contributed to findings in previous studies that used explicitly presented primes and targets. Thus, a continuous priming paradigm where targets are unknown to participants is used with noun-noun-verb triads filling agent, patient, and action roles in situation schemas (tourist, car, rent). Results replicate priming of single nouns preceding related verbs but do not suggest an additive effect for two nouns versus one. The absence of additive priming suggests that attentional processes may have been a factor in previous research.

Rehabilitation of language in expressive aphasias: a literature review

Objective

This paper reviews the methodological characteristics of studies on rehabilitation of expressive aphasia, describing the techniques of rehabilitation used.

Methods

The databases Medline, Science Direct and PubMed were searched for relevant articles (January 1999 to December 2011) using the keywords Expressive / Broca / Nonfluent Aphasia, combined with Language or Speech Rehabilitation / Therapy / Intervention.

Results

A total of 56 articles were retrieved describing rehabilitation techniques, including 22 with a focus on lexical processing, 18 on syntax stimulation, seven with the aim of developing speech and nine with multiple foci.

Conclusion

A variety of techniques and theoretical approaches are available, highlighting the heterogeneity of research in this area. This diversity can be justified by the uniqueness of patients' language deficits, making it difficult to generalize. In addition, there is a need to combine the formal measures of tests with measures of pragmatic and social skills of communication to determine the effect of rehabilitation on the patient's daily life.

Using principles of learning to inform language therapy design for children with specific language impairment

BACKGROUND

Language treatment for children with specific language impairment (SLI) often takes months to achieve moderate results. Interventions often do not incorporate the principles that are known to affect learning in unimpaired learners.

AIMS

To outline some key findings about learning in typical populations and to suggest a model of how they might be applied to language treatment design as a catalyst for further research and discussion.

METHODS & PROCEDURES

Three main principles of implicit learning are reviewed: variability, complexity and sleep-dependent consolidation. After explaining these principles, evidence is provided as to how they influence learning tasks in unimpaired learners. Information is reviewed on principles of learning as they apply to impaired populations, current treatment designs are also reviewed that conform to the principles, and ways in which principles of learning might be incorporated into language treatment design are demonstrated.

MAIN CONTRIBUTION

This paper provides an outline for how theoretical knowledge might be applied to clinical practice in an effort to promote discussion.

CONCLUSIONS & IMPLICATIONS

Although the authors look forward to more specific details on how the principles of learning relate to impaired populations, there is ample evidence to suggest that these principles should be considered during treatment design.

Effects of word frequency and modality on sentence comprehension impairments in people with aphasia

PURPOSE

It is well known that people with aphasia have sentence comprehension impairments. The present study investigated whether lexical factors contribute to sentence comprehension impairments in both the auditory and written modalities using online measures of sentence processing.

METHOD

People with aphasia and non brain-damaged controls participated in the experiment (n = 8 per group). Twenty-one sentence pairs containing high- and low-frequency words were presented in self-paced listening and reading tasks. The sentences were syntactically simple and differed only in the critical words. The dependent variables were response times for critical segments of the sentence and accuracy on the comprehension questions.

RESULTS

The results showed that word frequency influences performance on measures of sentence comprehension in people with aphasia. The accuracy data on the comprehension questions suggested that people with aphasia have more difficulty understanding sentences containing low-frequency words in the written compared to auditory modality. Both group and single-case analyses of the response time data also indicated that people with aphasia experience more difficulty with reading than listening.

CONCLUSION

Sentence comprehension in people with aphasia is influenced by word frequency and presentation modality.

Development of a theoretically based treatment for sentence comprehension deficits in individuals with aphasia

PURPOSE

Two new treatments, 1 based on sentence to picture matching (SPM) and the other on object manipulation (OM), that train participants on the thematic roles of sentences using pictures or by manipulating objects were piloted.

METHOD

Using a single-subject multiple-baseline design, sentence comprehension was trained on the affected sentence type in 1 task-related protocol in 15 participants with aphasia. The 2 tasks were SPM and OM; the treatment stimuli were object relatives, object clefts, passives, and unaccusatives, as well as two control structures-object relatives with a complex noun phrase (NP) and active sentences with three NPs.

RESULTS

The criteria for efficacious treatment was an increase in the level of performance from the pretreatment probes to the posttreatment probes for the treated structure such that accuracy rose from at or below chance to above chance and either (a) accuracy rose by 33% or (b) the effect size was 2.6. Based on these criteria, the success rate for training the target structure was 2/6 participants in the SPM condition and 4/7 participants in the OM condition.

CONCLUSION

The outcome of this study illustrates the utility of this theoretically motivated and efficacious treatment for sentence comprehension deficits in individuals with aphasia.

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.

Effects of semantic elaboration and typicality on picture naming in Alzheimer disease

PURPOSE

Individuals with probable Alzheimer disease (pAD) are frequently impaired at picture naming. This study examined whether a semantic elaboration task would facilitate naming in pAD, and whether training either semantically typical or atypical stimulus items facilitated generalized improvement in picture naming and category generation tasks.

METHODS

Twelve adults with mild-moderate pAD participated in the study. Participants performed an experimental semantic elaboration training task using a subset of typical items from one category and atypical items from another category. The third category, acted as a control (i.e., no items were trained). The study assessed change in category generation and a picture naming within the three target categories.

RESULTS

Individuals showed significantly improved category generation and naming, but changes were not limited to trained categories. Naming of trained atypical items improved significantly. Participants showed significantly improved naming of untrained typical items from categories trained with typical items.

CONCLUSIONS

Semantic elaboration of typical items within a semantic category can lead to generalized improvement in other typical items in the category in mild-moderate pAD. This is consistent with theories postulating that typical category items share overlapping distributed representations. Further exploration of the effects of semantic elaboration on word-finding in pAD is warranted, especially the possibility of within-category generalization.

Recent developments in functional and structural imaging of aphasia recovery after stroke

BACKGROUND: Functional and structural neuroimaging techniques can increase our knowledge about the neural processes underlying recovery from post-stroke language impairments (aphasia). AIMS: In the present review we highlight recent developments in neuroimaging research of aphasia recovery. MAIN CONTRIBUTION: We review (a) cross-sectional findings in aphasia with regard to local brain functions and functional connectivity, (b) structural and functional imaging findings using longitudinal (intervention) paradigms, (c) new adjunct treatments that are guided by functional imaging techniques (e.g., electrical brain stimulation) and (d) studies related to the prognosis of language recovery and treatment responsiveness after stroke. CONCLUSIONS: More recent developments in data acquisition and analysis foster better understanding and more realistic modelling of the neural substrates of language recovery after stroke. Moreover, the combination of different neuroimaging protocols can provide converging evidence for neuroplastic brain remodelling during spontaneous and treatment-induced recovery. Researchers are also beginning to use sophisticated imaging analyses to improve accuracy of prognosis, which may eventually improve patient care by allowing for more efficient treatment planning. Brain stimulation techniques offer a new and exciting way to improve the recovery potential after stroke.

Treatment of semantic verb classes in aphasia: acquisition and generalization effects

Verb retrieval difficulties are common in aphasia; however, few successful treatments have been documented (e.g. Conroy, P., Sage, K., & Lambon Ralph, M. A. (2006) . Towards theory-driven therapies for aphasic verb impairments: A review of current theory and practice. Aphasiology, 20, 1159-1185). This study investigated the efficacy of a novel verb retrieval treatment in two individuals with aphasia who experience verb retrieval difficulty. It involved training verb classes with large (e.g. cut verbs) and limited (e.g. contact verbs) sets of semantic features. Based on action representation theories, semantically based training of cut verbs was predicted to generalize to retrieval of untrained cut and contact verbs. One participant improved on trained verbs whereas the other participant did not. Neither participant demonstrated within nor across-class generalization to untrained verbs. However, both participants significantly improved in verb naming as measured by An Object and Action Naming Battery, and their predominant error pattern changed from noun to verb substitutions. Therefore, both participants improved in overall verb retrieval strategies despite limited success with verbs trained in this treatment. Implications for the design of future treatments are discussed.

Verb production during action naming in semantic dementia

In contrast with widely documented deficits of semantic knowledge relating to object concepts and the corresponding nouns in semantic dementia (SD), little is known about action semantics and verb production in SD. The degradation of action semantic knowledge was studied in 5 patients with SD compared with 17 matched control participants in an action naming task based on video clips. The pattern of errors, involving a huge proportion of generic verbs (e.g. "to remove" versus "to peel") relative to responses in control subjects, suggested a hierarchical, bottom-up deficit of action knowledge in SD patients. In addition, abnormal responses in patients consisted of verbs that were semantically related to the expected verbs produced by control subjects (e.g. "to undress" versus "to peel" for the action [To peel_orange]). This study suggests that, in SD, non-canonical responses to action naming reflect lack of both specificity and semantic relatedness relative to the expected responses.

LEARNING OUTCOMES

As a result of this activity, readers will recognize that semantic word knowledge disappears in semantic dementia using video clips of object-related actions. As a result of this activity, readers will discover that this semantic impairment followed a hierarchical pattern with the more specific verbs vanishing first.

Broca's area: rethinking classical concepts from a neuroscience perspective

Just about one and one-half centuries ago, Paul Broca identified the posterior third left frontal convolution of the human brain as a critical area for speech production. Although years of cerebrovascular accident localization studies partially confirmed Broca's claim, recent years have seen a clarification and expansion of the role Broca's area plays in serial processing of language and speech as well as a probable role in nonlinguistic processing. This article will review some of the more recent anatomical and physiological research, including lesion studies, imaging research, and interoperative electrocortical stimulation studies. The article will summarize the research on the role of the human inferior frontal gyrus in lexical, phonologic, and grammatical production, the so-called "mirror mechanism" and other aspects of cognitive processing and motor execution.

Effects of syntactic and semantic argument structure on sentence repetition in agrammatism: Things we can learn from particles and prepositions

BACKGROUND

Sentence production impairment in aphasia has been attributed to several possible sources that are not mutually exclusive. Linguistic accounts often attribute the difficulty to the complexity of a verb's syntactic and/or semantic argument structure. Cognitive processing accounts emphasise the reduced processing capacity observed in agrammatic aphasia, which in turn has been attributed to reduced semantic short-term memory (STM) or slowed processing.

AIMS

In this study we used verb particles and prepositions to investigate effects of differences in syntactic and semantic argument structure on sentence repetition in aphasia. We predicted that verb particles and sentences containing verb-particle constructions would be easier to repeat than prepositions and prepositional transitive sentences, as the former have a less-complex semantic and syntactic argument structure than the latter. Also, semantic and phonological spans were assessed to determine if a reduction in either capacity correlates with repetition ability.

METHODS & PROCEDURES

Participants were eight individuals with chronic aphasia. The experimental task was repetition of transitive sentences balanced for length and lexical content containing either verb particles or prepositional object structures. Accuracy of sentence repetition and repetition of verb particles and prepositions within sentences was examined. We calculated the effect of structural complexity on the sentence repetition task as the difference between proportion correct of verb-particle constructions and prepositional transitives. Semantic and phonological STM spans and word spans were also assessed and correlated with this measure of the structural complexity effect on sentence repetition.

OUTCOMES & RESULTS

Verb-particle sentences were repeated correctly significantly more often than prepositional transitive sentences, and within those sentences verbal particles were repeated correctly significantly more often than prepositions. The effect was strongly associated with fluency scores: it was present in participants with low fluency scores, but not in those with high fluency scores. The phonological, but not the semantic, STM probe span measure correlated with both the difference in accurate repetition of verb-particle and prepositional transitive sentences and the particles and prepositions within those sentences.

CONCLUSIONS

Results indicate that differences in argument structure of particle and preposition constructions influence sentence repetition in agrammatic aphasia. The finding that lower fluency scores are associated with poorer performance on more complex structures suggests that this effect is associated with agrammatism. The impact of these structural distinctions between particles and prepositions should be taken into account during development of treatment stimuli for those with agrammatism.

Overt use of a tactile-kinesthetic strategy shifts to covert processing in rehabilitation of letter-by-letter reading

BACKGROUND: Letter-by-letter readers identify each letter of the word they are reading serially in left to right order before recognizing the word. When their letter naming is also impaired, letter-by-letter reading is inaccurate and can render even single word reading very poor. Tactile and/or kinesthetic strategies have been reported to improve reading in these patients, but only under certain conditions or for a limited set of stimuli. AIMS: The primary aim of the current study was to determine whether a tactile/kinesthetic treatment could significantly improve reading specifically under normal reading conditions, i.e. reading untrained words presented in free vision and read without overt use of the strategy. METHODS #ENTITYSTARTX00026; PROCEDURES: Three chronic letter-by-letter readers participated in a tactile/kinesthetic treatment aimed at first improving letter naming accuracy (phase 1) and then letter-by-letter reading speed (phase 2). In a multiple case series design, accuracy and speed of reading untrained words without overt use of the trained tactile/kinesthetic strategy was assessed before phase 1, after phase 1 and again after phase 2. OUTCOMES #ENTITYSTARTX00026; RESULTS: All three patients significantly improved both their speed and accuracy reading untrained words without overt use of the trained tactile/kinesthetic strategy. All three patients required the additional practice in phase 2 to achieve significant improvement. Treatment did not target sentence level reading, yet two of the three patients became so adept that they could read entire sentences. CONCLUSIONS: This study replicates previous findings on the efficacy of tactile/kinesthetic treatment for letter-by-letter readers with poor letter naming. It further demonstrates that this treatment can alter cognitive processing such that words never specifically trained can be read in free vision without overtly using the trained strategy. The data suggest that an important element in achieving this level of generalization is continuing training beyond the point of initial mastery (i.e. accurate letter naming).

Sentactics®: Computer-Automated Treatment of Underlying Forms

BACKGROUND: Treatment of Underlying Forms (TUF) is a linguistically-based treatment for improving agrammatic sentence deficits, which enjoys a substantial database attesting to its efficacy for improving both sentence comprehension and production in agrammatic aphasia. However, TUF requires considerable linguistic background to administer and administration time can exceed the number of treatment sessions allotted in toto for reimbursement by third party payors in the United States. Thus, Sentactics®, an interactive computer system that enables delivery of TUF by a virtual clinician was developed. AIMS: This study tested the effects of Sentactics® on the acquisition and generalized production and comprehension of complex sentences. Additionally, a direct comparison of the results of computer-delivered Sentactics® and clinician-delivered TUF was undertaken. METHODS #ENTITYSTARTX00026; PROCEDURES: Twelve agrammatic aphasic speakers participated in the study, with six receiving Sentactics® and six serving as experimental controls, who received no treatment. All participants were administered pre- and post-treatment sentence comprehension and production tests and other measures to evaluate the effects of Sentactics®. Performance of the Sentactics® group also was compared to eight agrammatic patients who previously received clinician-delivered TUF treatment, identical to that delivered via Sentactics®, but with a human clinician. OUTCOMES #ENTITYSTARTX00026; RESULTS: Sentactics® significantly improved all six aphasic speakers' ability to comprehend and produce both trained and untrained, linguistically related, complex sentences as compared to six agrammatic control participants who did not receive Sentactics®. In addition, comparing the results of the Sentactics® to clinician-delivered TUF revealed no significant differences between approaches with regard to acquisition or generalization patterns. CONCLUSIONS: These data provide further support for the efficacy of TUF and demonstrate the viability of computer-delivered therapies in the field of aphasia treatment.

Neural plasticity and treatment-induced recovery of sentence processing in agrammatism

This study examined patterns of neural activation associated with treatment-induced improvement of complex sentence production (and comprehension) in six individuals with stroke-induced agrammatic aphasia, taking into account possible alterations in blood flow often associated with stroke, including delayed time-to-peak of the hemodynamic response function (HRF) and hypoperfused tissue. Aphasic participants performed an auditory verification fMRI task, processing object cleft, subject cleft, and simple active sentences, prior to and following a course of Treatment of Underlying Forms (TUF; Thompson et al., 2003), a linguistically based approach for treating aphasic sentence deficits, which targeted object relative clause constructions. The patients also were scanned in a long-trials task to examine HRFs, to account for any local deviations resulting from stroke, and perfusion images were obtained to evaluate regions of hypoperfused tissue. Region-of-interest (ROI) analyses were conducted (bilaterally), modeling participant-specific local HRFs in left hemisphere areas activated by 12 healthy age-matched volunteers performing the same task, including the middle and inferior frontal gyri, precentral gyrus, middle and superior temporal gyri, and insula, and additional regions associated with complex syntactic processing, including the posterior perisylvian and superior parietal cortices. Results showed that, despite individual variation in activation differences from pre- to post-treatment scans in the aphasic participants, main-effects analyses revealed a general shift from left superior temporal activation to more posterior temporoparietal areas, bilaterally. Time-to-peak of these responses correlated negatively with blood flow, as measured with perfusion imaging.

A treatment sequence for phonological alexia/agraphia

PURPOSE

Damage to left perisylvian cortex often results in impaired phonological processing abilities with written language profiles consistent with phonological alexia and phonological agraphia. The purpose of this article was to examine a behavioral treatment sequence for such individuals intended to strengthen phonological processing and links between phonology and orthography, as well as train a means to maximize use of residual orthographic and phonological knowledge for spelling.

METHOD

Two women with persistent impairments of written language and phonological processing following damage to left perisylvian cortical regions participated in this study. Both exhibited characteristic features of phonological alexia and agraphia in that reading and spelling performance for real words was better preserved than nonwords (lexicality effect). A 2-stage treatment protocol was administered to strengthen sublexical skills (phonological treatment) and to train interactive use of lexical and sublexical information to maximize spelling performance (interactive treatment).

RESULTS

Both participants improved phonological processing abilities and reading/spelling via the sublexical route. They also improved spelling of real words and were able to detect and correct most residual errors using an electronic spelling aid.

CONCLUSIONS

Behavioral treatment served to strengthen phonological skills supporting reading and spelling, and provided a functional compensatory strategy to overcome residual weaknesses.

Triangulating speech sound generalization

Generalization refers to the extension of learned behaviours to novel conditions, and it is one of the criteria by which the effectiveness and efficiency of a remediation programme may be judged. This article extracts principles of generalization from the treatment literature, and provides examples of how this information may be used to help guide treatment decisions. Included is a discussion of client, clinician, and treatment variables that may contribute to the generalization process.

Automatic processing of wh- and NP-movement in agrammatic aphasia: Evidence from eyetracking

Individuals with agrammatic Broca's aphasia show deficits in comprehension of non-canonical wh-movement and NP-movement sentences. Previous work using eyetracking has found that agrammatic and unimpaired listeners show very similar patterns of automatic processing for wh-movement sentences. The current study attempts to replicate this finding for sentences with wh-movement (in object relatives in the current study) and to extend it to sentences with NP movement (passives). For wh-movement sentences, aphasic and control participants' eye-movements differed most dramatically in late regions of the sentence and post-offset, with aphasic participants exhibiting lingering attention to a salient but grammatically impermissible competitor. The eye-movement differences between correct and incorrect trials for wh-movement sentences were similar, with incorrect trials also exhibiting competition from an impermissible interpretation late in the sentence. Furthermore, the two groups exhibited similar eye-movement patterns in response to passive NP-movement sentences, but showed little evidence of gap-filling for passives. The results suggest that aphasic and unimpaired individuals may generate similar representations during comprehension, but that aphasics are highly vulnerable to interference from alternative interpretations (Ferreira, 2003).

The northwestern anagram test: measuring sentence production in primary progressive aphasia

Primary progressive aphasia (PPA) is a clinical dementia syndrome with early symptoms of language dysfunction. Postmortem findings are varied and include Alzheimer disease and frontotemporal lobar degeneration (FTLD), both tauopathies and TAR DNA binding protein (TDP-43) proteinopathies. Clinical-pathological correlations in PPA are complex but the presence in the clinical profile of agrammatism has a high association with tauopathy. Grammatical competence is difficult to assess in the clinical setting with available methods. This article describes the Northwestern Anagram Test (NAT), a new clinical measure of sentence production. A total of 16 patients with PPA and their controls assembled single printed words to create sentences describing pictures. Northwestern Anagram Test performance was significantly correlated with a measure of sentence production and with aphasia severity but not with measures of naming, single word comprehension, object recognition, or motor speech. The NAT can be used to assess syntax competence when patients cannot be tested with measures that require intact speech production.

Treatment for lexical retrieval using abstract and concrete words in persons with aphasia: Effect of complexity

BACKGROUND: The significance of imageability and concreteness as factors for lexical tasks in aphasic individuals is under debate. No previous treatment studies have looked specifically at training abstract words compared to concrete for improved lexical retrieval in patients with chronic aphasia. AIM: The goal of the present study was to determine the efficacy of a treatment for lexical retrieval that is based on models of lexical processing by utilizing abstractness as a mode of complexity. It was hypothesized that training abstract words in a category will result in improvement of those words and generalization to untrained target concrete words in the same category. Training concrete words in a category, however, will result in the retrieval of trained concrete words, but not generalization to target abstract words. METHODS #ENTITYSTARTX00026; PROCEDURES: A single subject experimental design across participants and behaviors was used to examine treatment and generalization. Generative naming for three categories (church, hospital, courthouse) was tested during baseline and treatment. Each treatment session was carried out in five steps: (1) category sorting, (2) feature selection, (3) yes/no feature questions, (4) word recall, and (5) free generative naming. RESULTS: Although participant 1 demonstrated neither significant learning nor generalization during abstract or concrete word training, participants 2, 3, and 4 showed significant learning during abstract word training and generalization to untrained concrete words. Participants 3 and 4 were also trained on concrete words which they improved on but did not show generalization to untrained abstract words. CONCLUSIONS: The results of the present experiment support our hypothesis that training abstract words would result in greater learning and generalization to untrained concrete words. They also tentatively support the idea that generalization is facilitated by treatment focusing on more complex constructions (Kiran & Thompson, 2003; Thompson, Shapiro, Kiran, & Sobecks, 2003).

Effect of Verb Network Strengthening Treatment (VNeST) on Lexical Retrieval of Content Words in Sentences in Persons with Aphasia

BACKGROUND: Verb Network Strengthening Treatment (VNeST) is a semantic treatment that aims to improve lexical retrieval of content words in sentence context by promoting systematic retrieval of verbs (e.g., measure) and their thematic roles (i.e., agent (doer of the action, e.g., carpenter, chef)) and patient (receiver of the action, e.g., lumber, sugar)). VNeST is influenced by Loverso and colleagues (e.g., Loverso, Selinger, and Prescott, 1979), who used "verb as core" treatment to improve sentence production with encouraging results, and McRae and colleagues, who showed that verbs prime typical agents (e.g., pray-nun) and patients (arrest-criminal) (Ferretti, McRae, & Hatherell, 2001) and vice-versa (McRae, Hare, Elman, & Ferretti, 2005). AIMS: There are four specific questions in this study. Does training a set of verbs using VNeST generalize to the ability to produce 1) an agent (carpenter), trained verb (measure), and patient (stairs) in response to novel picture stimuli and 2) an agent (nurse), untrained semantically related verb (weigh), and patient (baby) in response to novel picture stimuli? 3) Are generalization effects maintained?, and 4) Does VNeST generalize to the ability to retrieve nouns and verbs not directly related to treatment items in single word naming, picture description and connected speech tasks? METHODS #ENTITYSTARTX00026; PROCEDURES: Four participants with aphasia participated. Participants received VNeST, which involves retrieval of agent-patient pairs (e.g., chef/sugar, surveyor/land) related to trained verbs (e.g., measure), two times per week. A single subject, repeated probe, multiple baseline experimental design was used. Generalization to sentence production for sentences containing trained verbs and untrained semantically related verbs was tested weekly. OUTCOMES #ENTITYSTARTX00026; RESULTS: Results demonstrated generalization to lexical retrieval of content words in sentences with trained and untrained verbs across participants. Additionally, pre- to post-treatment generalization was observed on single verb and noun naming and lexical retrieval in sentences across a variety of tasks across participants. Generalization to connected speech was observed for 3 of 4 participants. CONCLUSIONS: Though preliminary, these results indicate that VNeST may be effective in promoting generalization from single word naming to connected speech in persons with moderate aphasia. A number of clinical implications related to treatment efficiency are discussed.

Sentence comprehension in agrammatic aphasia: history and variability to clinical implications

Individuals with Broca's aphasia often present with deficits in their ability to comprehend non-canonical sentences. This has been contrastingly characterized as a systematic loss of specific grammatical abilities or as individual variability in the dynamics between processing load and resource availability. The present study investigated sentence level comprehension in participants with Broca's aphasia in an attempt to integrate these contrasting views into a clinically useful process. Two participants diagnosed with Broca's aphasia were assessed using a sentence-to-picture matching paradigm and a truth-value judgement task, across sentence constructions thought to be problematic for this population. The data demonstrate markedly different patterns of performance between participants, as well as variability within participants (e.g. by sentence type). These findings support the notion of individual performance variability in persons with aphasia. Syntactic theory was instructive for assessing sentence level comprehension, leading to a clinically relevant process of identifying treatment targets considering both performance variability and syntactic complexity for this population.

Typicality of inanimate category exemplars in aphasia treatment: further evidence for semantic complexity

PURPOSE

The typicality treatment approach on improving naming was investigated within 2 inanimate categories (furniture and clothing) using a single-subject experimental design across participants and behaviors in 5 patients with aphasia.

METHOD

Participants received a semantic feature treatment to improve naming of either typical or atypical items within semantic categories, whereas generalization was tested to untrained items of the category. The order of typicality and category trained was counterbalanced across participants.

RESULTS

Results indicated that 2 out of 4 patients trained on naming of atypical examples demonstrated generalization to naming untrained typical examples. One patient showed trends toward generalization but did not achieve criterion. Furthermore, all 4 patients trained on typical examples demonstrated no generalized naming to untrained atypical examples within the category. Also, analysis of errors indicated an evolution of errors as a result of treatment, from those with no apparent relationship to the target to primarily semantic and phonemic paraphasias.

CONCLUSION

These results extend our previous findings (S. Kiran & C. K. Thompson, 2003a) to patients with nonfluent aphasia and to inanimate categories such as furniture and clothing. Additionally, the results provide support for the claim that training atypical examples is a more efficient method of facilitating generalization to untrained items within a category than training typical examples (S. Kiran, 2007).