Antje S. Mefferd

A novel fixed-target task to determine articulatory speed constraints in persons with amyotrophic lateral sclerosis.

PURPOSE The goal of this study was to determine if talkers with ALS are limited in their ability to increase lower lip and jaw speed at an early stage of the disease when their speaking rate and intelligibility are only minimally or not affected. METHOD A novel metronome paced fixed-target task was used to assess movement speed capacities during lower lip and jaw oscillations in seven talkers with ALS and seven age and gender matched controls. RESULTS Lower lip peak speeds were significantly lower in talkers with mild ALS than in healthy talkers suggesting a lower lip speed constraint in talkers with mild ALS. Jaw peak speeds tended to be lower, but jaw displacements tended to be larger in talkers with mild ALS than in healthy talkers. Because greater speeds are typically expected for larger displacements, outcomes also suggest a jaw speed constraint in talkers with mild ALS. CONCLUSIONS Lower lip and jaw peak speeds may be sensitive measures to identify bulbar motor performance decline at an early stage of the disease when speaking rate and intelligibility are only minimally affected. LEARNING OUTCOMES The reader will be able to explain two different articulatory strategies to increase speaking rate and understand why fast speech tasks and diadochokinetic pseudo-speech tasks are not suited to assess articulatory speed capacity in healthy and impaired talkers. The reader will also be able to explain how orofacial movement speed capacity can be tested using a fixed-target task and how ALS affects lower lip and jaw speed capacities during the early stages of the disease.

Hydration in older adults: The contribution of bioelectrical impedance analysis

Abstract The sensory and gastrointestinal changes that occur with ageing affect older adults’ food and liquid intake. Any decreased liquid intake increases the risk for dehydration. This increased dehydration risk is compounded in older adults with dysphagia. The availability of a non-invasive and easily administered way to document hydration levels in older adults is critical, particularly for adults in residential care. This pilot study investigated the contribution of bioelectrical impedance analysis to measure hydration in 19 older women in residential care: 13 who viewed themselves as healthy and six with dysphagia. Mann-Whitney U analyses documented no significant between-group differences for Total Body Water (TBW), Fat Free Mass (FFM), Fat Mass (FM), and percentage Body Fat (%BF). However, when compared to previously published data for age-matched women, the TBW and FFM values of the two participant groups were notably less, and FM and %BF values were notably greater than expected. If results are confirmed through continued investigation, such findings may suggest that long-term care facilities are unique environments in which all older residents can be considered at-risk for dehydration and support the use of BIA as a non-invasive tool to assess and monitor their hydration status.

Speaking rate effects on articulatory pattern consistency in talkers with mild ALS

Abstract This study investigated speaking rate effects on articulatory pattern consistency in talkers with mild amyotrophic lateral sclerosis (ALS) to better understand speech rate declines during the early stages of speech deterioration. Eight talkers with mild ALS and 11 controls repeated a sentence at their typical rate, an accelerated rate, and a reduced rate. Lip and jaw movements were captured using a 3-D motion capture system. Results showed that talkers with ALS produced more consistent articulatory patterns during typical speech than did controls. Further, rate reduction resulted in diminished pattern consistency in both groups. Fast speech also elicited less consistent articulatory patterns in talkers with ALS. Controls, by contrast, tended to produce more consistent patterns during fast speech. Relatively inconsistent patterns during fast speech suggest that ALS may negatively affect articulatory control when the speech motor system operates near its performance limit. Relatively consistent patterns during typical speech indicate a successful adaption to disease-related articulatory deficits. Rate reduction does not appear to benefit articulatory stability during early stages of speech decline.

Articulatory-to-Acoustic Relations in Talkers With Dysarthria: A First Analysis

PURPOSE The primary purpose of this study was to determine the strength of interspeaker and intraspeaker articulatory-to-acoustic relations of vowel contrast produced by talkers with dysarthria and controls. METHODS Six talkers with amyotrophic lateral sclerosis (ALS), six talkers with Parkinsons disease (PD), and 12 controls repeated a sentence at typical, slow, and fast rates. Tongue displacements and acoustic vowel distances were measured to determine articulatory and acoustic vowel contrasts. RESULTS Interspeaker articulatory-to-acoustic relations were strong for talkers with PD and controls but weak for talkers with ALS and controls. Further, predominantly moderate and strong intraspeaker articulatory-to-acoustic relations were found in response to rate modulations; however, correlation coefficients were significantly lower in talkers with ALS than in controls. CONCLUSIONS The findings on interspeaker articulatory-to-acoustic relations suggested that the degree of tongue displacement can be accurately inferred from the degree of acoustic vowel contrast in talkers with PD but not in talkers with ALS. Findings on intraspeaker articulatory-to-acoustic relations generally supported the longstanding notion that speaking rate-induced changes in tongue displacement evoke similar changes in acoustic vowel contrast. Differential effects of the pathophysiology on inter- and intraspeaker articulatory-to-acoustic relations are discussed.

Spatiotemporal movement variability in ALS: Speaking rate effects on tongue, lower lip, and jaw motor control

PURPOSE Although it is frequently presumed that bulbar muscle degeneration in Amyotrophic Lateral Sclerosis (ALS) is associated with progressive loss of speech motor control, empirical evidence is limited. Furthermore, because speaking rate slows with disease progression and rate manipulations are used to improve intelligibility in ALS, this study sought to (i) determine between and within-group differences in articulatory motor control as a result of speaking rate changes and (ii) identify the strength of association between articulatory motor control and speech impairment severity. METHOD Ten talkers with ALS and 11 healthy controls repeated the target sentence at habitual, fast, and slow rates. The spatiotemporal variability index (STI) was calculated to determine tongue, lower lip, and jaw movement variability. RESULTS During habitual speech, talkers with mild-moderate dysarthria displayed significantly lower tongue and lip movement variability whereas those with severe dysarthria showed greater variability compared to controls. Within-group rate effects were significant only for talkers with ALS. Specifically, lip and tongue movement variability significantly increased during slow speech relative to habitual and fast speech. Finally, preliminary associations between speech impairment severity and movement variability were moderate to strong in talkers with ALS. CONCLUSION Between-group differences for habitual speech and within-group effects for slow speech replicated previous findings for lower lip and jaw movements. Preliminary findings of moderate to strong associations between speech impairment severity and STI suggest that articulatory variability may vary from pathologically low (possibly indicating articulatory compensation) to pathologically high variability (possibly indicating loss of control) with dysarthria progression in ALS.

Tongue- and jaw-specific contributions to increased vowel acoustic contrast in response to slow, loud, and clear speech in talkers with dysarthria

Slow, loud, and clear speech can elicit increased acoustic vowel contrast in talkers with dysarthria. However, articulator-specific changes in response to these speech modifications and their relative contribution to vowel acoustic changes remain poorly understood despite the fact that these three speech modulations are commonly used as speech treatments to increase intelligibility in dysarthria. This preliminary study examined tongue and jaw movements in talkers with Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS) using electromagnetic articulography. Participants repeated the phrase “See a kite again” five times under four speech conditions: typical, slow, loud, and clear speech. Tongue movements were decoupled from the jaw to determine the relative contribution of the jaw and tongue to the overall tongue composite movement during the diphthong /ai/ in “kite”. In the acoustic signal, the F2 minimum during /a/ and the F2 maximum during /i/ and their corresponding F1 values were extracted...

Tongue strength and endurance: comparison in active and non-active young and older adults

Abstract Purpose: Tongue strength and endurance are important for swallowing and upper airway patency. Physical activity positively affects targeted and non-targeted skeletal muscles; however, little is known about the indirect effect of physical activity on tongue muscles. This study sought to determine if tongue muscle performance differs between highly active and non-active individuals and if such an effect varies with age. Method: Forty-eight healthy adults were divided into two age groups (24 young, 20.96 ± 3.22 years; 24 older, 65 ± 3.72 years) and further divided into highly active and non-active based on The General Practice Physical Activity Questionnaire. Tongue strength (TS) and tongue endurance (TE) were obtained using the Iowa Oral Performance Instrument. Result: A significant main effect of activity level on TS and TE was found. Although the main effect of age on TS and TE and age × activity level interactions were not significant, the effect of activity level on TS and TE was more pronounced in older adults than younger adults. Conclusion: Findings suggest physical activity may affect TS and TE, particularly in older adults. Future research is warranted to understand the underlying mechanisms contributing to these group differences. Clinical implications of these findings are discussed.

Associations between tongue movement pattern consistency and formant movement pattern consistency in response to speech behavioral modifications.

The degree of speech movement pattern consistency can provide information about speech motor control. Although tongue motor control is particularly important because of the tongues primary contribution to the speech acoustic signal, capturing tongue movements during speech remains difficult and costly. This study sought to determine if formant movements could be used to estimate tongue movement pattern consistency indirectly. Two age groups (seven young adults and seven older adults) and six speech conditions (typical, slow, loud, clear, fast, bite block speech) were selected to elicit an age- and task-dependent performance range in tongue movement pattern consistency. Kinematic and acoustic spatiotemporal indexes (STI) were calculated based on sentence-length tongue movement and formant movement signals, respectively. Kinematic and acoustic STI values showed strong associations across talkers and moderate to strong associations for each talker across speech tasks; although, in cases where task-related tongue motor performance changes were relatively small, the acoustic STI values were poorly associated with kinematic STI values. These findings suggest that, depending on the sensitivity needs, formant movement pattern consistency could be used in lieu of direct kinematic analysis to indirectly examine speech motor control.

Bite block effects on vowel acoustics in talkers with amyotrophic lateral Sclerosis and Parkinson’s Disease

Amytrophic Lateral Sclerosis (ALS) affects predominantly the tongue and leaves the jaw relatively spared. By contrast, Parkinson’s disease (PD) is thought to affect the motor system globally with minimal jaw movements potentially further limiting tongue articulatory movements. However, currently only few studies have directly investigated articulator-specific contributions to deviant speech acoustics in talkers with dysarthria. In this study, a 10 mm bite block was used to decouple tongue and jaw and delineate their specific contributions on vowel acoustics in talkers with distinctly different impairment profiles. Acoustic vowel contrast was examined during sentence repetitions produced by talkers with ALS, PD, and controls under jaw-free and jaw-fixed conditions. Preliminary findings of seven speakers per group revealed that acoustic vowel contrast was significantly lower during the jaw-fixed than the jaw-free condition in ALS. However, in PD acoustic vowel contrast tended to be greater when the jaw was ...

Adaptation and aftereffects in response to bite block perturbation

Although speakers can instantly adapt to the presence of a bite block (BB), they also refine their compensatory behavior over time. However, the extent to which BB perturbations elicit aftereffects and the mechanisms that contribute to refinement and aftereffects remain unknown. In this study, speakers belonging to either a practice or a no-practice group produced sentence repetitions under five conditions: PRE-BB (jaw-free), BB1 (jaw-fixed, initial BB exposure), BB2 (jaw-fixed, after 20 minutes of BB exposure), POST1 (jaw-free, immediately after BB removal), POST2 (jaw-free, one minute after BB removal). All speakers held a 10mm BB in place for 20 minutes with the practice group reading aloud and the no-practice group sitting quietly. Jaw and posterior tongue kinematics were examined during the vowel /i/ embedded in the word “please” using electromagnetic articulography. Preliminary findings (14 speakers) revealed a significant main effect of condition only. That is, relative to PRE-BB, tongue height did...