Neurobehavioral response to increased treatment dosage in chronic, mild aphasia

Intensive aphasia treatment has been employed with equivocal results likely due to variability in the severity of participants as well as in the parameters that comprise intensity (e.g., session duration). Constraint Induced Language Therapy (CILT; Pulvermüller et al., 2001) is an intensive aphasia therapy that has been replicated successfully and also tends to use similar dosage parameters across replication studies (e.g., Barthel, et al, 2008; Maher, 2006). Meinzer and colleagues (2008; 2007) found that it was their most severely affected participants who tended to benefit most from treatment of CILT, positing that those who had withdrawn from verbal communication the most were those most likely to benefit from the forced use inherent to CILT. It is also possible that since CILT and associated treatment materials was designed for more impaired participants; those more mildly affected may have been insufficiently challenged during the treatment period. If so, it follows that that neural change would be less likely. The present study employed a multiple probe technique (McReynolds & Kearns, 1983) in which CILT was delivered at a dosage of three hours per day for twenty days. A hierarchy of complex stimuli was created to pose adequate challenge for two individuals with mild aphasia. Discourse analysis and naming response time were used to quantify changes in language efficiency. In addition, fMRI scanning was performed at four time points throughout the treatment process in order to compare potential language changes to changes in neural activation patterns. These results are expected to add to the limited fMRI data currently available for intensive aphasia treatment

Integrating aphasia into stroke best practices: A Canadian KTE strategy

This poster reports on the activities to date of the Stroke and Aphasia Canada team including results of a Canadian Institutes of Health Research (CIHR) Knowledge Translation (KT) planning grant (grant #290592, 2013)

Using Virtual Clinicians to Promote Functional Communication Skills in Aphasia

Persons with aphasia (PWA) re-enter their community after their rehabilitation program is ended. Thus it is incumbent on rehabilitation specialists to incorporate training in using residual language skills for functional communication [1]. Evidence indicates that language abilities improve with continued treatment, even during chronic stages of aphasia (refs) For optimal generalization, PWA need to practice language in everyday living situations. Virtual reality technology is a method of providing home-based therapeutic interventions. A valuable potential of virtual reality technology is that it supports the successful generalization of residual language skills to functional communication situations. Traditionally, role-playing [2] and script training [3] have been used to improve functional communication in PWA. A more recent approach has been the adaptation of scripts through the implementation of virtual technology. [4]. We report progress on a project that aims to develop a virtual clinician that is capable of recognizing a variety of potential responses in the context of functional communication scenarios. Our goal is to develop a virtual clinician-human interaction system that can be used independently by PWA to practice and improve communication skills. This involves development of software that will support a spoken dialog system (SDS) that can interact autonomously with an individual and can be configured to personalize treatment [5]. As use of virtual technology in aphasia rehabilitation increases, questions about the physical and psychosocial factors that influence successful use of residual communication skills need to be resolved. Thus, a second aim of this project, the topic of this paper, is to determine whether interactive dialogues between a client and virtual clinician differ in the quantity and quality of the client’s language output compared to dialogues between client and human clinician. Although the potential of using virtual clinicians is promising, it must be determined if individuals with aphasia (or other language disorder) will be responsive to the virtual clinician and produce as much language in this context as they would during dialogues with human clinicians. We addressed two hypotheses in this study: 1. For PWA, practice with dialogues that focus on everyday activities will improve quality and quantity of verbal output in those dialogues. 2. For PWA, verbal output practiced in dialogues with a virtual clinician and a human clinician will yield similar amounts of verbal output as measured by information units in the dialogues

Design Principles and Outcomes of "Aphasia House" an University Intensive Comprehensive Aphasia Program (ICAP)

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Localizing lesion locations to predict extent of aphasia recovery

Extensive research has related specific lesion locations to language impairment in aphasia. However, far less work has focused on the patterns of brain damage that predict prognosis in aphasia. The current study examined brain damage as a predictor of language recovery in acute patients with aphasia caused by stroke. Damage to the left posterior middle temporal gyrus (MTG) and left pars triangularis predicted poor recovery of speech production and MTG damage predicted less recovery of speech comprehension. These findings suggest that brain changes associated with language recovery rely on preservation and recruitment of the aforementioned areas in the left hemisphere

The Auditory Comprehension of Unaccusative Verbs in Aphasia

Some persons with aphasia, particularly those diagnosed with a Broca’s aphasia, exhibit a delayed time course of lexical activation in canonically ordered S-V-O sentences (Ferrill et al., 2012) and delayed re-activation of displaced arguments in sentences that contain syntactic dependencies (Love et al., 2008). These patterns support the Delayed Lexical Activation (DLA) hypothesis: Lexical activation is delayed relative to the normal case, and thus lexical activation and syntactic operations are de-synchronized; that is, lexical access is too slow for normally fast-acting syntactic operations. This delay in lexical access leads to what appear to be syntactic comprehension deficits in aphasia. In the current study we further examined lexical activation during sentence comprehension in persons with aphasia by using unaccusative verbs. Unaccusative verbs are a type of intransitive verb with a single argument that is base generated in object position and displaced to the surface subject position, leaving behind a copy or trace (‘gap’) of the movement (see, for example, Burzio, 1986), as in: 1. The girl vanished Thus there is a syntactic dependency between the two positions. When encountering sentences that contain syntactic dependencies (e.g., object relatives, Wh-questions) neurologically unimpaired individuals immediately reactivate the displaced argument at the gap (Shapiro et al., 1999; Love et al., 2008). In contrast to this immediate reactivation, prior findings indicate that neurologically unimpaired individuals do not reactivate the displaced argument in similar sentences with unaccusative verbs until 750ms downstream from the gap (Friedmann et al., 2008). This built-in delay observed with unaccusative verbs in neurologically healthy participants provides a unique opportunity to further examine lexical delays in individuals with Broca’s aphasia. Importantly, individuals with Broca’s aphasia may have unaccusative verb deficits. Previous research has found that persons with aphasia have difficulty producing unaccusative verbs. Offline truth-value judgment tasks with intransitive sentences containing unaccusative verbs do not reveal comprehension deficits (Lee & Thompson, 2004). However, in a sentence-picture matching task, McAllister et al. (2009) found lower accuracy for intransitive sentences that contained unaccusative verbs than transitive sentences. We entertain the following hypothesis: The delayed lexical access routines better synchronize with the delay of reactivating the argument of unaccusatives, suggesting that individuals with Broca’s aphasia should evince a pattern like that of unimpaired individuals. Alternatively, participants with Broca’s aphasia might show activation even further downstream from the gap, given that in other sentence constructions containing syntactic dependencies they exhibit a delayed pattern of reactivation compared to neurologically unimpaired individuals

Garden-Path Effects and Recovery in Aphasia

How people resolve and recover from syntactic ambiguity has been a central research topic in the psycholinguistic literature on sentence comprehension. It has attracted less attention in the literature on communicative impairments. However, there is increasing evidence that brain damage can affect how adults understand syntactically ambiguous sentences, both for right-hemisphere brain damage (e.g., Schneiderman & Saddy, 1988) and left-hemisphere damage (e.g., Novick, Trueswell & Thompson-Schill, 2005). Understanding how persons with aphasia (PWA) comprehend syntactically ambiguous sentences is therefore important to evaluating their communicative function, specifically their sentence comprehension ability. Syntactically ambiguous sentences are often referred to as garden-path sentences (Bever, 1970). These sentences lead comprehenders “down the garden path”: they cause readers or listeners to briefly misinterpret an ambiguous word or phrase, initially misanalyzing its syntactic role in the sentence. Subsequent information then indicates that this initial interpretation was incorrect, forcing comprehenders to reinterpret the sentence. This garden-path effect has been consistently found in healthy young and older adults (Christianson, et al., 2001, 2006; Ferreira & Henderson, 1991; Frazier & Rayner, 1982). Syntactic ambiguity resolution may be particularly strongly affected by reduced cognitive function such as reduced working memory (WM), common in healthy aging (e.g., Christianson, et al., 2006; Kemper et al., 2004). Kemper and colleagues (2004) found that older adults showed larger garden-path effects than younger adults, spending longer reading and re-reading garden-path sentences, and that these age-related differences were mediated by WM. This finding provides evidence of the importance of WM in resolving syntactic ambiguities. Christianson, et al. (2006) found that older adults’ comprehension question accuracy for garden-path sentences was correlated with their WM span. This finding provides evidence of the role of WM in successful recovery from a garden path. However, there has been little research on whether PWA also exhibit garden-path effects in their real-time comprehension of syntactically ambiguous sentences, or how successfully they recover from such garden paths. PWA have also been argued to have reduced WM capacity which contributes to their sentence comprehension deficits (e.g., Miyake, Carpenter & Just, 1994). WM is likely involved in the reanalysis of garden-path sentences (Kemper, et al., 2004), since reanalysis requires performing operations on structures held in memory. This study therefore examined the comprehension of garden-path sentences in PWA, and tested how their on-line garden-path effects and their off-line garden-path recovery were predicted by WM and short-term memory (STM)

Crosslinguistic Generalization of Semantic Treatment in Aphasia: Evidence from the Indian Context

The last two decades witnessed several novel treatment approaches to aphasia therapy. Semantic feature-based therapy is one of such treatment approaches that gained considerable research attention (Boyle & Coelho, 1995). More importantly, this treatment approach has been found effective in bilingual persons with aphasia. For instance, Edmonds and Kiran (2006) administered semantic feature based therapy in Spanish-English bilingual persons with aphasia and reported of crosslinguistic generalization of treatment effect to untreated language. This promising research, however, needs to be replicated and extended to novel language pairs. Research on crosslinguistic generalization of treatment effects is of paramount importance to multilingual countries like India. For instance, with several hundreds of languages and dialects spoken across India and with the pervasive use of English as second language, speech language pathologists (SLPs) in the country are often baffled on the selection of language for treatment in bilingual persons with aphasia. Empirical evidence from Indian languages would add confidence to the SLPs while selecting language for treatment in person with aphasia. In this context, the current study aimed to replicate and extend the earlier findings on crosslinguistic generalization of treatment effects in bilingual persons with aphasia to the Indian context

Cataphora processing in agrammatic aphasia: Eye movement evidence for integration deficits

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Main Concept Production in Persons with Aphasia: A Comparison of Subtypes

Narrative abilities are negatively impacted in persons with aphasia (PWAs), with even the mildest PWAs producing narratives that, though well-structured, are characterized by reduced lexical diversity, complexity, content, length, coherence, and more (e.g., Andreetta, Cantagallo, & Marini, 2012; Capilouto, Wright, and Wagovich, 2006; Fergadiotis & Wright, 2011; Nicholas & Brookshire, 1995; Ulatowska, North, & Macaluso-Haynes, 1981). Even those categorized as “not aphasic by WAB” (NABW) produce significantly different story retell narratives compared to typical and aphasic peers (Author2, Dillow, & Author1, 2013). Diminished narrative abilities, and associated reduced functional communication, have a marked negative impact on quality of life (QoL) in PWAs, more so than physical limitations that accompany stroke (Hilari, 2011; Northcott & Hilari, 2011). Indeed, narrative ability may be a better predictor of life participation and QoL than traditionally administered outcome measures (Ross & Wertz, 1999), making imperative the advancement of narrative assessment and treatment. Three primary barriers to narrative assessment impede widespread use - standardization, norm-reference, and time constraints. AphasiaBank developers (http://talkbank.org/AphasiaBank/) addressed the first barrier by making available a standard discourse protocol. Regarding the second barrier, norm-referenced Main Concept (MC) lists based on 150+ control transcripts for three different types of discourse were recently developed using AphasiaBank (Author2, Campbell, Williams, Dillow, & Author1, 2013). The MC lists included concepts spoken by 50% of the control population. The authors elected to develop MC lists primarily because 1) MC analysis is a reliable and valid method of assessing narrative adequacy in PWAs (Nicholas & Brookshire, 1995), and 2) generation of standardized, norm-referenced, non-transcription-based MC lists would reduce the amount of time required for narrative assessment (third barrier). Previous MC research has revealed differences between controls and PWAs, and between fluent and non-fluent PWAs (Kong, 2009, 2011; Nicholas & Brookshire, 1995). Previous MC studies have also combined certain codes (see Discussion), which may lead to inaccurate representation of communicative abilities and/or masking of differences between subtypes. We extracted lengthy narrative samples of a large group of PWAs and analyzed the samples with a multi-level MC coding system using norm-referenced MCs in order to determine 1) if there were significant differences in MC production between different aphasia subtypes, and 2) if so, which subtypes were significantly different from each othe