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Phonological processing in primary progressive aphasia
No full textPrimary progressive aphasia (PPA) is a debilitating condition wherein speech and language deteriorate as a result of neurodegenerative disease. Three variants of PPA are now recognized, each of which shows a unique constellation of speech-language deficits and pattern of underlying atrophy in the brain (Gorno-Tempini et al., 2011). The variants include a nonfluent/agrammatic type (nfvPPA), characterized by syntactic and motor speech deficits and fronto-insular atrophy in the left hemisphere. The semantic variant (svPPA) shows degradation of semantic knowledge in the context of anterior and inferior temporal lobe atrophy (left hemisphere greater than right). Finally, the more recently characterized logopenic variant (lvPPA) shows impairments in naming and repetition that are thought to be phonological in nature. This variant, associated with atrophy of temporoparietal regions in the left hemisphere, has also been referred to as the “phonological” variant of PPA due to observed deficits on tasks that require phonological storage (i.e., the “phonological loop”) and to the presence of phonological paraphasias in connected speech (Gorno-Tempini et al., 2008). Impaired phonological processing has been considered a unique feature of the logopenic variant of PPA, however, phonological skills have not been thoroughly characterized across the three variants.
Recent models of the functional neuroanatomy of language propose two pathways by which speech is processed in the brain (Hickok & Poeppel, 2007). A dorsal pathway involving temporoparietal and posterior frontal structures is thought to be involved in mapping phonological representations onto articulatory representations. A ventral pathway located in the middle and inferior temporal lobes is considered crucial for mapping phonological representations onto lexical-semantic representations. Both the dorsal and ventral streams emanate from a common cortical region in posterior, superior temporal cortex/sulcus that appears critical to the mental representation of phonology. We investigated phonological processing in PPA, with the goal of identifying whether patterns of performance in the different variants support this functional-anatomical framework. Based on our knowledge of the locus of anatomical damage in the subtypes of PPA, we hypothesized that patients with damage to dorsal route structures (nonfluent and logopenic variants) would show greater impairment on phonological processing tasks, whereas patients with damage to ventral route structures (semantic variant) would show relative preservation of phonological abilities
Qualitative analyses of verbal fluency performance in persons with right hemisphere damage
No full textIn the context of ongoing debates on the arguable role of right hemisphere in lexico-semantic processing, we investigated the clustering, switching, and time-course of lexical retrieval in right hemisphere damage (PwRHD). “Clustering refers to the production of words within the semantic or phonemic subcategories and switching refers to the ability to shift between the clusters” (Troyer, Moscovitch, & Winocur, 1997, p. 140). Time course analysis permits variation in retrieval process with passage of time. Previously, Beausoleil, Fortin, Le Blanc, and Joanette (2003) investigated the time course of lexical retrieval in people with RHD and reported that their participants retrieved maximum words at the beginning of the trial, a pattern similar to that exhibited by people with left hemisphere damage and non-brain damaged groups of their study. However, the clustering and switching remain to be investigated in people with right hemisphere damage
Semafore: preliminary results.
Get PDFThere is abundant evidence from single-case studies and case series that some treatment methods for word retrieval can result in substantial improvements, at least with target words (see e.g. Nickels, 2002 for a review).
But there is still a question of which method is best, and for which participants.
Since Howard et al (1985) there has been a broad distinction between ‘phonological’ and ‘semantic’ therapy; the first emphasising the word form of the target, while the second uses techniques designed to activate/explore its semantic features. Nettleton & Lesser (1991) were the first of many to argue that semantic therapy methods would benefit most people with aphasia with a semantic deficit and phonological therapy would benefit those with a post-semantic deficit. This view was challenged by Howard (2000) who argued that there was no good evidence that either approach was better and that both provided the participant with the information needed to link a semantic representation to a phonological representation. Facilitation experiments reported by Howard et al (2006) supported that view: semantic facilitation resulted in the greatest improvements for the participants with post-semantic difficulties in word retrieval
The Effect of Emotion on Verbal Recall in Traumatic Brain Injury
No full textIndividuals with traumatic brain injury (TBI) have impairments in identifying emotion in social and pragmatic communication (Ben-David, van Lieshout, & Leszcz, 2011). These deficits include difficulty with correctly matching emotion in facial expressions (Watts & Douglas, 2006), interpreting prosody of speech (Dimoska, McDonald, Pell, Tate, & James, 2010), retrieving words (Hough, 2008) and determining the perspectives of other individuals using theory of mind (McDonald & Flanagan, 2004). However, little research has focused on the processing of emotional content in verbal recall.
The purpose of this study is to determine the effects of stimulus emotional content on the ability of individuals with TBI to recall words from lists and content units from paragraphs. Results from the study have clinical significance because the tasks may serve as appraisal instruments for determining the level of emotional processing impairment associated with traumatic brain injury and document the importance of emotional content in selecting stimuli for treatment intervention
A multimodal neurolinguistic treatment approach for conduction aphasia: A single case study.
Get PDFConduction aphasia is characterized by significant changes to language output including phonetically complex paraphasias, severely impaired repetition, and difficulty comprehending specific lexical information in isolation despite relatively good comprehension of the ‘gist’ of the message (Baldo, Klostermann, & Dronkers, 2008; Goodglass, 1992; Joanette, Keller, & Lecours, 1980; Kohn, 1984). Nickels, Howard, and Best (1997) proposed that individuals with conduction aphasia experience difficulty processing auditory-verbal information secondary to disruption in articulatory loop processes. Baldo et al. (2008), using sentence level stimuli, further suggested that persons with conduction aphasia rely more on the semantic processes versus articulatory loop processes when interpreting messages. Such deficits in conduction aphasia are not exclusive to language output channels (Baldo et al., 2008; Caramazza, Basili, & Koller, 1981; Shallice & Warrington, 1977; Warrington & Shallice, 1969).
In the current study, we combined the work of Nickels et al. (1997) and Baldo et al. (2008) to develop a novel multimodal, combined semantic and a phonological approach for treatment for an individual with chronic conduction aphasia. The goal of this treatment was to improve auditory comprehension (e.g., word and sentence level) and increase propositional spoken language (e.g., single word and discourse level). We hypothesized that priming the semantic network would facilitate access to the phonological representation of trained words and as a result, improved auditory comprehension and lexical retrieval
Better pathways for people with aphasia
No full textIntegrated care pathways, clinical pathways, patient journeys and care maps are interchangeable terminology to describe tools which promote organised and efficient patient care based on the best available evidence and guidelines (Kwan et al., 2004). A care pathway can further be described as a ‘complex intervention for the mutual decision making and organisation of care processes for a well-defined group of patients during a well-defined period’ (European Pathway Association, 2007). The use of care pathways allows continuous assessment of clinical processes and outcomes against current best practice and guidelines.
As evidence-based practice become progressively more important for effective health delivery, increased research use within aphasia rehabilitation is paramount. Currently, stroke clinical guidelines offer very little in the form of aphasia-specific recommendations to inform practice. Our systematic review of clinical practice guidelines revealed a paucity of high-quality aphasia rehabilitation guidelines internationally (Rohde et al, in press). Integrated care pathways are gaining increasing popularity in health care delivery and offer a potential solution to the lack of evidence-based recommendations within aphasia rehabilitation.
The AARP aims to improve the overall patient journey for people with aphasia through providing clinicians with access to the best evidence in a dynamic and user-friendly format. In addition to the principles of integrated care pathways, the AARP utilises the theory of evidence-based practice through combining the best available evidence with family/client perspectives and clinical expertise. The AARP is also underpinned by the principles of knowledge transfer and exchange (KTE) which aims to close the research-practice gap in order to realise and maximise the benefits of research within the practice setting.
Hence the aims of this paper are to:
a) Present results of the systematic review of clinical guidelines in stroke and aphasia
b) Describe the consensus document that maps the AARP.
c) Describe the translation of a highly complex system to a user-friendly web-based system
Changes in Functional Connectivity Associated with Direct Training and Generalization Effects of a Theory-Based Generative Naming Treatment
Get PDFPersons with aphasia who are trained to generate abstract words (e.g., justice) in a specific context-category (e.g., courthouse) have been shown to improve not only on the trained items, but also on concrete words (e.g., lawyer) in the same context-category (Kiran, Sandberg, & Abbott, 2009). However, the underlying neural mechanism of this generalization effect is unknown. Abstract and concrete words provide a unique opportunity to study specific neural activity related to direct training and generalization because they are thought to be processed differently by the brain (Binder, Desai, Graves, & Conant, 2009; Wang, Conder, Blitzer, & Shinkareva, 2010), but are linked in such a way as to promote generalization (Kiran et al., 2009). The current study examines the neural activation and functional connectivity patterns of abstract and concrete word processing in persons with aphasia before and after training abstract word retrieval to help uncover the neural mechanisms associated with direct training and generalization
Phonological alexia and agraphia: Should we remediate phonological awareness, phonological memory, or both?
No full textTherefore, the purpose of this study was to examine the utility of treating verbal STM to maximize utilization of trained/residual sublexical skills for reading/spelling. Two participants with aphasia and phonological alexia/agraphia received a verbal STM treatment combined with a phonological awareness protocol. We hypothesized that the addition of verbal STM training to the phonological treatment would circumvent residual deficits in mapping sublexical knowledge onto written language processing following phonological treatment, providing a more effective and/or efficient treatment outcome in terms of functional reading and writing skills
Propositional Idea Density: Computerized analysis to determine effects of presence and severity of aphasia
Get PDFThis paper presents research that aimed to extend the available analyses of informativeness of aphasic discourse. A ‘proposition’ can be defined as a linguistic relation and its associated arguments (Kintsch & Keenan, 1973; Turner & Greene, 1977), and has been used as an index of informativeness in research on language and aging. The proportion of propositions in a text (Propositional Idea Density – PD) has been found to be a sensitive index of age-associated cognitive impairment and dementia (Riley, Snowdon, Desrosiers, & Markesbery, 2005). The research on PD has primarily used manual analysis methods, noting high training needs for raters to ensure adequate inter-coder and intra-coder reliability, as has also been found in analyses of informativeness in the field of aphasia (Nicholas & Brookshire, 1993; Oelschlaeger & Thorne, 1999; Yorkston & Beukelman, 1980). The development of a computer program, Computerized Propositional Idea Density Rater known as CPIDR (Brown, Snodgrass, & Covington, 2007; Brown, Snodgrass, Kemper, Herman, & Covington, 2008) has made the process of calculating PD accessible to untrained individuals. The benefits of a computer-based program are further seen in reliability, with 100% consistency when re-counting a single sample, and inter-rater reliability of 97% when compared to manual calculations which is more reliable than most human coders (Brown, et al., 2008). The present research made use of this computerised analysis of PD to investigate the effects of aphasia on informativeness. It was hypothesised that information content, as measured by PD, would be significantly reduced in the oral discourse of people with aphasia when compared to non-aphasic controls, and that PD would decrease with increasing aphasia severity as determined by Western Aphasia Battery - Aphasia Quotient (Kertesz, 2006)
Acquisition, Maintenance and Generalization of Script Training: A Comparison of Errorful and Error-Reducing Conditions
No full textRelatively few studies have investigated errorless versus errorful learning in aphasia, and most have focused on the single word level. In a review of a series of anomia studies, Fillingham et al. (2003) found that rate of success was equivalent for errorless and errorful conditions; the number of therapies using errorful techniques outweighed those based on errorless learning; errorless approaches were likely to achieve positive immediate effects, but many of the errorless studies did not report long term effects and generalization; and there was a lack of studies reporting a direct comparison of errorful and errorless learning.
More recent work has continued to support the findings that there is no essential difference between error-free and errorless learning approaches (Middleton & Schwartz, 2012). However, none have investigated and contrasted the errorless/errorful learning paradigm in the production of phrases and sentences.
This pilot study directly measures and compare the acquisition, maintenance and generalization of script-training under both error-reducing and errorful conditions. We hypothesized that error-reducing training would improve acquisition of a trained script while errorful learning would improve maintenance of the trained script and generalization to untrained scripts