Diane Garst

Treating apraxia of speech (AOS) with EMA-supplied visual augmented feedback

Background: Previous studies have suggested that visual augmented feedback provided by electromagnetic articulography (EMA) helps persons with apraxia of speech (AOS) recover speech motor control following stroke (e.g., Katz et al., 2007). However, the data are few, both in terms of the variety of participants and the speech motor targets investigated. Aims: This study was designed to determine whether EMA supplied feedback improves articulatory accuracy in an adult with acquired AOS. We also examined whether reduced feedback frequency results in (1) decreased performance during acquisition and (2) enhanced maintenance and generalisation of the targeted behaviours. Methods & Procedures: A multiple-baseline across-behaviours design was used to assess the efficacy of this treatment for an individual with AOS. Over a 27-week period, the participant received visual feedback provided by an EMA system for treatment of three groups of speech motor targets (SMTs): /j/, /θ/, and /t∫  / with various following VCs. The consonant clusters /br/ and /sw/ served as untreated controls. Frequency of feedback scheduling was 100% for /j/ and /t∫ /, and 50% for /θ/. Outcomes & Results: For the first group of SMTs treated, /j/, there was acquisition for 4/5 trained words. These were maintained post-treatment and at the long-term probe. Improved performance and maintenance were also noted for 5/8 untreated stimuli, with maintenance shown for most of these words by 1 month post-treatment. The next treated SMT, /θ/, showed acquisition for all five treated items. Two of these five targets were maintained one month post-treatment. All three untreated /θ/ probes showed generalisation, with two of these showing maintenance post-treatment. The third treated group of SMTs, /t∫/, showed improved performance for all of the five treated words. However, these gains could only be attributed to /t∫/ treatment for three of the five words. Two treated items appeared well maintained at 1 month post-treatment. Generalisation and maintenance were also noted for all six untreated /t∫ / words. However, generalisation from previously treated /j/ and /t∫/ targets was involved in their improved performance. The untrained (control) word data suggested that the gains noted for treated items did not result from across-the-board improvement or unassisted recovery. There were no consistent differences corresponding with low- versus high-frequency feedback conditions. Conclusions: Augmented kinematic feedback provided by an EMA system improved production for some, but not all, treated targets. Generalisation to untreated probes was also evident. Predictions concerning the effects of feedback frequency on the acquisition, maintenance, and transfer of trained behaviours were not supported.

The role of prosody in a case of foreign accent syndrome (FAS).

Foreign accent syndrome (FAS) is a rare disorder characterized by the emergence of a perceived foreign accent following brain damage. The symptomotology, functional bases, and neural substrates of this disorder are still being elucidated. In this case study, acoustic analyses were performed on the speech of a 46‐year old monolingual female who presented with FAS of unknown aetiology. The patient had a pseudo‐accent frequently described as ‘Swedish’ or ‘Eastern European’. Stop consonant VOT, consonant burst spectra and duration, vowel durations, formant frequencies, and trajectories were analysed, along with prosodic cues for lexical stress assignment and sentence‐level intonation. Results indicated VOT values were generally preserved, while there was a strong tendency to realize the English alveolar flap as a full stop, and to produce flaps that had greater‐than‐normal closure durations. The spectral properties of the patients vowels resembled those of normal talkers (with the possible exceptions of decreased F1 values for /i/ and slight differences in formant dynamics for /u/, /o/, /i/, and /ϵ/). However, vowel durations were relatively long, contributing to exaggerated tense/lax contrasts. Token‐to‐token variability in vowel production was slightly higher than normal for duration, but not for formant frequency values. Lexical stress assignment was inaccurate and highly variable (with similar problems noted for non‐speech materials), and sentence level intonation showed occasional deviations from typical American English patterns. For this patient, an underlying timing/rhythm difficulty appeared responsible for the range of segmental and suprasegmental changes leading to the impression of a foreign accent.

Neural bases of the foreign accent syndrome: a functional magnetic resonance imaging case study.

Foreign accent syndrome (FAS) is a rare disorder characterized by the emergence of a perceived foreign accent following brain damage. Despite decades of study, little is known about the neural substrates involved in this disorder. In this case study, MRI images of the brain were obtained during a speech task for an American English-speaking monolingual female who presented with FAS of unknown etiology and was thought to sound ‘Swedish’ or ‘Eastern European’. On the basis of MR structural imaging, the patient was noted to have frontal lobe atrophy. An fMRI picture-naming task designed to broadly engage the speech motor network revealed predominantly left-hemisphere involvement, including activation of the (1) left superior temporal and medial frontal structures, (2) bilateral subcortical structures and thalamus, and (3) left cerebellum. The results suggest an instance of substantial brain reorganization for speech motor control.

Personal narratives in aphasia: understanding narrative competence.

Abstract Background: Personal narratives have been suggested as a way for persons post stroke to re-establish their identity. To relate tellable personal stories, narrative competence – along with its building blocks – is essential. Objective: The objective of this study was to describe narrative competence in persons with mild to moderate aphasia. It addressed the areas of coherence, clarity, temporal-causal structure, and reference in narratives. The study also examined the strategies used (evaluative language) as well as the topics and themes in personal narratives. Methods: Sixteen individuals with mild to moderate aphasia were asked to relate the story of their stroke and stories of a memorable and a frightening experience. Stories were elicited using a “willing listener” procedure. Responses were analyzed quantitatively in terms of the number of propositions and the instances of temporal-causal sequences, reference, and evaluation. Qualitative analysis was performed to determine the overall coherence and clarity of the narratives. Results: Narrative competence was present in the majority of participants. Although difficulties with reference were observed, high ratings of narrative coherence and clarity were attributed to sufficient amount of language, preserved temporal-causal sequencing, and the use of strategies (evaluative language). Conclusions: Narrative competence was exhibited in the personal narratives of individuals with mild to moderate aphasia. In addition to pinpointing essential elements of narrative competence, the use of personal narratives was deemed beneficial for both the clinician, by providing a better understanding of the individual with aphasia, and the individual with aphasia, by providing opportunities for self-disclosure.

Production and comprehension in aphasia: Gains and pitfalls in using macrostructure tasks in Aesop's fables

Abstract Macrostructures provide the global meaning of a text. Using Aesops fables, the main goal of this study has been to identify the advantages and limitations in using the macrostructure tasks of retell, summary, lesson, and gist as clinical tools in understanding 16 patients with mild-to-moderate aphasia. Results suggest that all of the macrostructure tasks are important in determining the production skills of patients with aphasia. Comprehension, on the other hand, is best determined through the macrostructure tasks of retell and lesson. In addition to the language processing skills of patients with aphasia, macrostructures also provide a cognitive picture of how patients manipulate information from stories (i.e., reducing information, making inferences, and generalizing didactic information). Inherent limitations, however, are seen when interpreting possible reasons why patients with aphasia are unable to perform some of these tasks. Given that the potential gains of using macrostructure tasks outweigh the limitations, this study suggests that macrostructures may have clinical value as a diagnostic tool in understanding the cognitive-linguistic processes of patients with brain injury.

The role of prosody in the foreign accent syndrome: A single‐subject study

Foreign accent syndrome (FAS) is an unusual motor speech disorder involving a perceived foreign accent resulting from brain damage. An important question concerning FAS is the role of prosodic deficits, including the extent to which difficulties in stress assignment may contribute to segmental errors. In this study, acoustic analyses were performed on the speech of a 46‐year‐old female patient who presented with a pseudo‐accent described as Swedish. Stop consonant VOT, consonant burst spectra and duration, and vowel formant frequencies and trajectories were analyzed, along with prosodic cues for lexical stress assignment and sentence‐level intonation. Results indicated that the patients vowels were centralized and realized with reduced dynamic specifications. There was a strong tendency to realize the English alveolar flap as a full stop, and to produce flaps that had greater‐than‐normal closure durations. Lexical stress assignment was frequently inaccurate and highly variable, with similar problems noted...

Effects of accent‐reduction techniques for the treatment of an individual with foreign accent syndrome

Foreign accent syndrome (FAS) is a rare speech motor disorder characterized by the emergence of a perceived foreign accent following brain damage. Although FAS has received increased attention in recent years, the issue of intervention for this disorder has not been systematically explored. In this study, an English‐speaking female patient with FAS thought to sound Swedish was given short‐term accent reduction treatment for selected front vowels (/i/, /■/, /e/), back vowels (/u/, /■/, /o/), and inter‐dental consonants (/θ/, /■/). Therapy consisted of structured practice on word lists containing targeted phonemes. A list of compound nouns was included as untreated control items. A multiple‐baseline across behaviors design was used to determine treatment efficacy. Probes were included for response generalization, maintenance, and long‐term retention. Digitally‐recorded productions by the FAS talker were played in randomized order to a phonetically‐trained listener who rated a targeted sound in each word as ...