A case study of bilingual neurogenic stuttering: Measures of fluency, emotion, and articulation rate.

INTRODUCTION: This study explores the features of bilingual neurogenic stuttering and the potential connection between emotion and articulation rate on speech disfluencies. METHOD: The participant is  a 59-year old, Yiddish-English bilingual male with a moderate non-fluent aphasia. Thirty-two narratives (16 in each language), elicited using cue words, were analyzed for frequency of disfluency, type of disfluency (stuttering vs. non-stuttering-like), word-type (content vs. function), within-word location of disfluency, and occurrence of accessory behaviors. Additionally, the percentage and type of emotion (positive vs. negative) expressed, and articulation rate (fluent syllables spoken/duration of fluent utterances) was assessed. RESULTS: Disfluency occurred in each language with approximately equal frequency. The most common stuttering-like disfluencies were repetitions (monosyllabic, sound, and syllable) and prolongations. The most common non-stuttering-like disfluencies were self-correction/revisions, phrase and multisyllabic word repetitions, and pauses (silent and filled). In both languages, disfluencies occurred on both content and function words, but primarily content words, and in any position of the word, although primarily initial position. No accessory behaviors were noted. There was a similar amount of emotion words used in each language although the first acquired language, L1/Yiddish, had an overall more positive tone, and his second acquired language, L2/English, had a more negative tone. Additionally, there was a negative relationship between emotion and the number of disfluencies in L1/Yiddish, and a positive relationship in L2/English. A faster articulation rate was found in his native and more proficient language, Yiddish, than English. There was a negative relationship between articulation rate and the number of disfluencies in L1/Yiddish, and a positive relationship in L2/English. CONCLUSIONS: Cross-linguistics differences for emotion and articulation rate demonstrates that these aspects impact on fluency and contributes to the disfluencies in each language. Clinical implications of the study demonstrates the importance of assessment of bilingual (i.e., proficiency and dominance) and fluency features of each language in the diagnostic process and the significance of considering emotional processes and articulation rate as part of a comprehensive intervention plan for acquired stuttering.

A case series comparison of semantically focused vs. phonologically focused cued naming treatment in aphasia.

There is a lack of clarity in the field regarding how to best predict which naming treatment will be most beneficial for a particular individual with aphasia. The purpose of this study was to elucidate whether or not semantic or phonological therapy differentially impacts on outcomes for people with a range of different aphasic profiles when given both therapies. A single-participant design, with multiple repeated baselines for naming, replicated across four participants, was used. Participants were provided with a counterbalanced order of Semantic Feature Analysis (SFA) and Phonological Components Analysis (PCA) treatment. Findings demonstrated differential effects across participants. This seemed to be influenced by factors such as severity of anomia, order of treatment presentation, and capacity limits. Clinical implications of these findings highlight the importance of expanding our picture of a participant's behaviours to consider what other important factors can inform intervention decisions.

Electrophysiological indices of brain activity to content and function words in discourse.

BACKGROUND: An increase in positivity of event-related potentials (ERPs) at the lateral anterior sites has been hypothesized to be an index of semantic and discourse processing, with the right lateral anterior positivity (LAP) showing particular sensitivity to discourse factors. However, the research investigating the LAP is limited; it is unclear whether the effect is driven by word class (function word versus content word) or by a more general process of structure building triggered by elements of a determiner phrase (DP). AIMS: To examine the neurophysiological indices of semantic/discourse integration using two different word categories (function versus content word) in the discourse contexts and to contrast processing of these word categories in meaningful versus nonsense contexts. METHODS & PROCEDURES: Planned comparisons of ERPs time locked to a function word stimulus 'the' and a content word stimulus 'cats' in sentence-initial position were conducted in both discourse and nonsense contexts to examine the time course of processing following these word forms. OUTCOMES & RESULTS: A repeated-measures analysis of variance (ANOVA) for the Discourse context revealed a significant interaction of condition and site due to greater positivity for 'the' relative to 'cats' at anterior and superior sites. In the Nonsense context, there was a significant interaction of condition, time and site due to greater positivity for 'the' relative to 'cats' at anterior sites from 150 to 350 ms post-stimulus offset and at superior sites from 150 to 200 ms post-stimulus offset. Overall, greater positivity for both 'the' and 'cats' was observed in the discourse relative to the nonsense context beginning approximately 150 ms post-stimulus offset. Additionally, topographical analyses were highly correlated for the two word categories when processing meaningful discourse. This topographical pattern could be characterized as a prominent right LAP. The LAP was attenuated when the target stimulus word initiated a nonsense context. CONCLUSIONS & IMPLICATIONS: The results of this study support the view that the right LAP is an index of general discourse processing rather than an index of word class. These findings demonstrate that the LAP can be used to study discourse processing in populations with compromised metalinguistic skills, such as adults with aphasia or traumatic brain injury.

An electrophysiological investigation of discourse coherence in healthy adults.

This study used event-related potentials (ERPs) to investigate discourse-coherence processing. Because there are scant data on ERP indices of discourse coherence in typical adults, it is important to study a non-clinical population before examining clinical populations. Twelve adults listened to a story with sentences in a coherent versus incoherent order. Sequences of nonsense syllables served as a control. ERPs in the 200-400 ms time window, reflecting phonological and lexical processing, and in the 600-900 ms time window, reflecting later discourse processing for integration, were investigated. Results revealed a right anterior and posterior positivity that was greater for coherent than for incoherent discourse during the 600-900 ms time window. These findings point to an index of discourse coherence and further suggest that ERPs can be used as a clinical tool to study discourse-processing disorders in populations with brain damage, such as aphasia and traumatic brain injury.