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Semantic Knowledge Use within Discourse Produced by Individuals with Anomic Aphasia
No full textAccording to the feature-specific model (Cree & McRae, 2003), semantic knowledge is a distributed network of features that are stored separately and can be impaired separately. These semantic features are the building blocks of the semantic knowledge system and of concepts in general. This has led researchers to using semantic features-based treatments to improve word retrieval abilities in adults with anomic aphasia. Semantic features-based treatments have been used to improve the ability for individuals with aphasia to re-establish connections between the semantic and lexical systems. Researchers have found that semantic features-based treatment, are typically successfully in improving verbal production abilities in adults with aphasia at the word level (Kiran & Roberts, 2010) and discourse (Boyle, 2004; Peach & Reuter, 2010; Rider, Wright, Marshall, & Page, 2008).
Recently, researchers have examined the utility of semantic features-based treatment for improving discourse production in adults with aphasia; however, few researchers have examined how the semantic knowledge is used within discourse. Armstrong (2001) examined the lexical patterns of verbs in discourse samples given by four participants with aphasia (PWA) and four healthy participants. Armstrong categorized verbs from personal recounts into one of five semantic-lexical categories (material, relational, mental, verbal, and behavioral). She found that PWA presented with different verb patterns that resulted in restricted communication. Moreover, the PWA had produced few mental and relational verbs. However, Armstrong included only lexical-semantic categories and they are connected by semantic relationships and possibly also grammatical relationships. To expand our knowledge of the appropriateness of using semantic features-based treatments at the discourse level, it important to understand how semantic knowledge is used beyond simply allowing access to lexical items. Unknown is if semantic knowledge use differs in adults with aphasia compared to cognitively healthy adults. These findings could have significant implications for how to apply semantic features-based treatments to improve discourse level abilities in adults with aphasia.
To this end, the purpose of the study, then, was to determine if the semantic knowledge and category types used in discourse by participants with anomic aphasia differed from those used by cognitively healthy participants. Certain semantic knowledge types and category types may be more difficult to access, integrate, or maintain in discourse for adults with anomic aphasia because producing discourse is cognitively demanding and requires processes external to lexical and semantic access. Therefore, we hypothesized that the discourse produced by participants with anomic aphasia would differ in the proportion of semantic knowledge and category types used
Computer-based cognitive intervention for aphasia: Behavioural and neurobiological outcomes
No full textAphasia, an acquired impairment of language that commonly occurs after stroke, can have significant consequences on all aspects of functioning of affected individuals. Some have proposed that the language deficits observed in aphasia are due to underlying limitations in cognitive processes that support language1-3. This ‘cognitive’ theory of aphasia is gaining increased attention in the research literature4, and is the impetus for the study of treatments for aphasia that target these underlying cognitive processes5-8. Indeed, studies of cognitive interventions in healthy populations have reported positive outcomes in behavioural (i.e. language and overall cognitive functioning9, 10) as well as neurobiological (i.e., brain function and/or structure11-13) domains, offering promise for the application of these types of interventions to aphasia.
Recently, computer-based ‘brain training’ programs have become increasingly prevalent. BrainFitness (BF) is one such commercially available program; it has been used to show improvement in auditory processing speed, attention and working memory in typically aging adults14, 15. This program has the potential to be a useful intervention for individuals with aphasia, but questions regarding the clinical utility of the program and neural correlates of training-related behavioural changes remain. The purpose of this study was to investigate the effect of BF training in people with aphasia using behavioural and neurobiological outcome measures
SemaFoRe: Comparing word retrieval treatments for aphasia via a randomised crossover trial.
No full textWord retrieval difficulties are one of the most prevalent symptoms of aphasia and we now have good evidence from single-case studies and case series that some treatment methods for word retrieval result in improvements, at least with target words (see e.g. Nickels, 2002, for a review). However, important questions remain about predicting outcome for an individual given a particular treatment.
This study, SemaFoRe, is a pilot cross-over RCT contrasting two commonly used treatments, Semantic Feature Analysis (SFA; Boyle, 2010) with Repetition in the Presence of the Picture (RIPP) . Both approaches have evidence to support them but they have some key differences: studies using SFA suggest generalisation to items not seen in treatment; it has a semantic focus and, potentially encourages clients to adopt a strategy to aid word retrieval. In contrast, RIPP has a phonological basis and is relatively simple therapy.
The SemaFoRe study aims to:
(i) Obtain the information needed to design and power a definitive cross-over RCT.
(ii) Compare the effectiveness of SFA and RIPP
(iii) Evaluate whether the effects of either treatment generalise
(iv) Explore prediction of benefit/gain.
Within the abstract we present data from an interim analysis of 9 participants who have completed all stages; by the time of the conference we will have final data from 23
Executive Attention deficits in aphasia: case studies
No full textMany features of language impairments in people with aphasia (PWA) suggest that they have problems with executive functions that control language use (Hula and McNeil, 2008). An outstanding question is the extent to which the executive functions affected in PWA apply in other cognitive domains (Murray, 2012) or are specific to language (Jefferies and Lambon Ralph, 2006; Hoffman et al., 2013). The Executive Attention model (Engle and Kane, 2004) provides a framework for examining this question. It claims the central executive consists of two interacting components: task maintenance, the ability to use task goals to exert proactive control that reduces interference, and conflict resolution, the ability to resolve conflicts generated by interference during goal-directed processing.
It is proposed that task maintenance is a domain-general capacity, and that conflict resolution is at least partially encapsulated, with specialized functions responsible for modality-specific interference. Therefore, PWA with task maintenance deficits should be affected in all cognitive areas, whereas PWA with conflict resolution impairments should be affected only in language functions, where they should show increased interference effects even in contexts of minimal task maintenance demand. Hypotheses were tested in two case studies
How do persons with aphasia describe concrete objects?
Full text linkFeature-based models of semantic processing are predicated on the notion that object concepts are constructed through the co-activation of semantic feature knowledge (e.g., Gainotti, 2006; Tyler et al., 2000; Warrington & Shallice, 1984). For example, for the concept DOG, semantic features include visual-perceptual (has fur, has wet nose), motor/action (walks, wags), and functional (guides the blind) information, along with knowledge of superordinate category membership (animal, mammal, canine), encyclopedic information (Lassie was a famous one, cats are afraid of them), and personal associations/opinions (Dogs are my favorite animal.). In fact, accessing such information is thought to activate retrieval of lexical knowledge for naming and learning the particular patterns of feature co-occurrence among different concepts allows us to categorize similar concepts using shared features (e.g., dogs, cats, mice: all breathe, eat, grow → are animals) distinguish similar concepts using distinctive features (dogs wag their tails, mice do not wag) and recognize concepts that are semantically unrelated (e.g., pencils are utensils used for writing and erasing, which are not activities frequently engaged in by dogs).
As yet unresolved is whether different types of ‘core’ semantic features may be more salient to identification and differentiation of different concept domains. Is it, as ‘sensory/function’ or sensorimotor-based hypotheses suggest, that disproportionate deficit to living concepts results from deficient processing of visual-perceptual features (e.g., apple: red, round), considered most salient for their differentiation; whereas disproportionate impairment to nonliving concepts results from deficient processing of functional or action features (pencil: used to write and erase) (e.g., Gainotti, 2006; Warrington and Shallice, 1984)? Or is it the interaction among shared and distinctive features across types that results in disproportionately deficient processing between domains, with shared form-function relations being more robust for living concepts, whereas for nonliving concepts it is more distinctive form-function associations (e.g., Tyler et al., 2000)? Debate is ongoing.
That said, a number of treatments for individuals with lexical retrieval impairment consequent to stroke-aphasia have been developed to take advantage of the relationship between access to semantic feature knowledge and activation of object names (see Boyle, 2010 and Kiran, 2007 for review). The purpose of this report is to add to the relatively small body of evidence regarding the types of semantic feature knowledge most accessible to those with aphasia and how that knowledge is accessed domains (i.e., living vs. nonliving)
Assessing the outcomes of a clinical trial: Primary outcome measures only tell part of the story
No full textIdentifying outcome measures that are sensitive to change and meaningful to participants is a challenge when designing clinical trials of complex communication interventions. Outcome measures encompassing participants’ perceptions of clinically meaningful change and their experience of the treatment process are frequently neglected. This paper presents an overview of the outcome measures used in a 3 arm clinical trial which aimed to investigate (i) social skills training for the person with TBI alone (which we have termed the TBI SOLO condition) and (ii) training communication partners to deal with difficult communication behaviors (the JOINT condition) compared to a delayed waitlist CONTROL condition. The paper asks two research questions:
1. What information did the self-report of perceived communication ability using the La Trobe Communication Questionnaire, and qualitative measures provide in addition to blinded ratings on the Adapted Kagan Scales, the primary outcome measure?
2.How did participants perceive the training experience as measured through post treatment interviews
Script Therapy or VNeST for Agrammatic Aphasia? A Pilot Study
Full text linkFluent language production can be determined by a number of linguistic factors including the ability to produce appropriate morphology, lexical retrieval, sentence production, grammatical form, and conversational discourse. Individuals with agrammatic aphasia may exhibit impaired lexical processing which greatly impedes their ability to construct sentences and communicate fluently. In particular, individuals with agrammatic aphasia exhibit difficulty in understanding or producing complex lexical items specifically in verb morphology as well as presenting with non-fluent, reduced speech lacking grammatical features, and a decrease in the production of verbs and nouns (Ballard & Thompson, 1999; Edmonds & Babb, 2011; Edmonds, Nadeau, & Kiran, 2009; Martin, Fink, & Laine, 2004; Nickels, 2002; & Raymer, & Ellsworth, 2002). Similarly, these individuals may demonstrate lexical retrieval deficits that are semantic in nature with difficulty accessing meaning and producing the correct forms of words (Libben, 2008). Also, these individuals may present difficulty both socially and linguistically processing discourse and conversation due to the nature of the interaction.
This study investigated which treatment, Script Therapy or Verb Network Strengthening Treatment (VNeST), was more beneficial in improving sentence production and conversational discourse with two individuals with agrammatic aphasia. Script therapy was chosen as it is a functional approach to aphasia therapy that can facilitate participation in personally relevant conversational activities. Structurally-based VNeST aims to improve lexical retrieval of content words in sentence context by promoting retrieval of verbs and their thematic roles (Edmonds et al., 2009). Previous studies suggest that both treatments help increase fluency in more complex sentence production that is necessary for discourse and conversation in individuals with agrammatic aphasia (Edmonds & Babb, 2011; Edmonds et al., 2009)
Comparing linguistic complexity and efficiency in conversations from Stimulation Therapy and Conversation Therapy in Aphasia
No full textThe ultimate goal for speech language pathology interventions for people with aphasia (PWA) is to be able to converse as normally as possible (Armstrong & Mortensen, 2006). However, there are numerous approaches to aphasia therapy as well as various outcome measures. For instance, Stimulation therapy (ST) relies on structured repetition and drill to elicit language, while conversation therapy (CT) uses client-clinician conversation and conversation analysis to improve everyday language. Most speech language pathologists use standardized tests or rating forms to measure treatment progress rather than measuring conversations (Boles, 1998).
We aimed to compare differences in linguistic complexity and efficiency in conversational outcomes in two treatment types, ST and CT. Researchers have examined the verbal abilities of PWA and aging adults by analyzing language samples (Capilouto et al., 2005; Kemper & Sumner, 2001); however few people have examined linguistic complexity in conversation as a treatment outcome measure.
Conversational efficiency measured in Correct Information Units (CIUs)/minute is a valid and reliable way to measure improvement in connected speech (Nicholas and Brookshire, 1993). Efficiency can be measured by calculating CIUs/minute or % CIUs. Researchers have used %CIUs to measure efficiency in conversations (Doyle, Goda & Spencer, 1995) and CIUs/minute in story-telling (Jacobs, 2001). However, no one has reported using CIUs/minute to measure efficiency during conversational interactions.
To address this we asked the following questions:
1. Does CT lead to a greater increase in linguistic complexity than ST based on the following measures of linguistic complexity:
a) Mean length of utterance (in words) (MLU)?
b) Type/token ratio (TTR)?
c) Number of different words (NDW)?
d) Percent of utterance responses?
e) Percent of simple utterances?
f) Percent of complex utterances?
g) Propositional density?
2. Does ST lead to improved efficiency of conversation?
3. Does CT lead to improved efficiency of conversation?
4. Is conversational efficiency different when ST is compared to CT?
5. Is there a difference between clinician and participant total talk time during conversation probes taken during both treatments
Semantic Feature Analysis: Further Examination of Outcomes
No full textSemantic Feature Analysis (SFA) has received considerable study over the past two decades as a word-retrieval treatment for aphasia (Boyle & Coelho, 1995; Lowell, Beeson, & Holland, 1995; Boyle, 2010; Wambaugh, Mauszycki, Cameron, Wright, & Nessler, 2013). SFA has been shown to have consistently positive acquisition effects (i.e., improvement of trained items), with generally positive but less predictable generalization effects (i.e., improvement in untrained items).
SFA was originally designed as a cognitive treatment for children and adolescents sustaining traumatic brain injury (TBI) (Haarbauer-Krupa, Moser, Smith, Sullivan & Szekeres, 1985). The therapy was designed as an “organizing process for thinking and verbal expression” (p.303).
Massaro and Tompkins (1994) operationalized SFA in a study with two participants with TBI. In keeping with the intentions of the original developers, Massaro and Tompkins measured SFA’s treatment effects in terms of increased production of semantically relevant content.
In the treatment of aphasia, the focus of SFA relative to outcomes has been naming accuracy. That is, SFA has been used as a means of systematically stimulating semantic networks to facilitate naming. Additionally, SFA has been considered to potentially serve as a mediating strategy for self-cuing accurate naming and/or a compensatory strategy for circumventing word-retrieval difficulties.
The current study was designed to elucidate the effects of SFA in aphasia treatment beyond naming accuracy. Given SFA was designed to improve verbal expression in general and may serve as a compensatory strategy, increased production of relevant content was of interest (after Tompkins & Massaro, 1994). In light of inconsistent generalization effects associated with SFA, the study was designed to explore its generalization effects relative to aspects of untreated items. Specifically, untreated items were controlled in terms of semantic relatedness, exposure in probing, and knowledge of phonological form
Can Drawing Enhance Word Retrieval Skills in Chronic Aphasia?
Full text linkAphasia disrupts multiple language processes with anomia being one of the most common and persisting deficit. Individuals may use a variety of compensatory strategies to circumvent the problem, including writing, gesturing, and drawing (Farias, Davis, & Harrington, 2006). However, few formal programs have promoted drawing as a means to facilitate communication. Approaches available typically use drawing as a language substitute rather than as a catalyst for enhancing verbal expression (Sacchett, 2002) and there has been minimal focus on drawing as a compensatory strategy for word retrieval (Lyon, 1995). Furthermore, training usually emphasizes recognizing drawing rather than a format for information exchange (Morgan & Helm-Estabrooks, 1987; Sacchett, 2002).
Semantic Feature Analysis (SFA) is a treatment approach based on the premise that although anomic individuals have difficulty retrieving words, ability to access semantic features of targets may be somewhat intact (Beeson, Holland, & Murray, 1995). The semantic system is accessed by producing words related to target words; in SFA, individuals incorporate these strategies as self-cues to retrieve target words (Boyle, 2004; Rider & Wright, 2008). To date, this approach has been used primarily to enhance verbal output only.
Taylor and Hough (2013) used drawing to explore improvement of word retrieval skills in a woman with chronic mixed aphasia. Results revealed improvement in naming treatment pictures with some generalization to untreated stimuli as well as relevant increases on the Boston Naming Test-II (BNT-II) (Kaplan, Goodglass, & Weintraub, 2001). The current study extends investigation of drawing treatment to examine if two males with chronic nonfluent aphasia improved ability to name pictured objects through a drawing protocol. In individual single subject designs, HR and TE underwent brief but intense treatment, incorporating drawing with SFA to improve retrieval