Assessing articulatory speed performance as a potential factor of slowed speech in older adults

Effects of Speaking Rate Changes on Speech Motor Variability in Adults

The relationship between speaking rate and speech motor variability was examined in three groups of neurotypical adults, n = 40; 15 young adults (18-30 years), 13 adults (31-40 years), and 12 middle-aged adults (41-50 years). Participants completed a connected speech task at three speaking rates (habitual, fast, and slow) where kinematic (lower lip movement) and acoustic data were obtained. Duration and variability were measured at each speaking rate. Findings revealed a complex relationship between speaking rate and variability. Adults from the middle age range (31-40 years) demonstrated shorter acoustic and kinematic durations compared with the oldest age group (41-50 years) during the habitual speaking rate condition. All adults demonstrated the greatest variability in the slow speaking rate condition, with no significant differences in variability between habitual and fast speaking rates. Interestingly, lip aperture variability was significantly lower in the youngest age group (18-30 years) compared with the two older groups during the fast speaking rate condition. Differences in measures of acoustic variability were not observed across the age levels. Strong negative correlations between kinematic/acoustic duration and lip aperture/acoustic variability in the youngest age group were revealed. Therefore, while a slow speaking rate does result in greater variability compared with habitual and fast speaking rates, longer durations of productions by the different age groups were not linked to higher spatiotemporal index (STI) values, suggesting that timing influences speech motor variability, but is not the sole contributor.

Speaking Rate, Immediate Memory, and Grammatical Processing in Prelingual Cochlear Implant Recipients

PURPOSE

This study examined the extent to which prelingual cochlear implant (CI) users show a slowed speaking rate compared with typical-hearing (TH) talkers when repeating various speech stimuli and whether the slowed speech of CI users relates to their immediate verbal memory.

METHOD

Participants included 10 prelingually deaf teenagers who received CIs before the age of 5 years and 10 age-matched TH teenagers. Participants repeated nonword syllable strings, word strings, and center-embedded sentences, with conditions balanced for syllable length and metrical structure. Participants' digit span forward and backward scores were collected to measure immediate verbal memory. Speaking rate data were analyzed using a mixed-design, repeated-measures analysis of variance, and the relationships between speaking rate and digit spans were evaluated by Pearson correlation.

RESULTS

Participants with CIs spoke more slowly than their TH peers during the sentence repetition task but not in the nonword string and word string repetition tasks. For the CI group, significant correlations emerged between speaking rate and digit span scores (both forward and backward) for the sentence repetition task but not for the nonword string or word string repetition task. For the TH group, no significant correlations were found.

CONCLUSIONS

The findings indicate a relation between slowed speech production, reduced immediate verbal memory, and diminished language capabilities of prelingual CI users, particularly for syntactic processing. These results support theories claiming that immediate memory, including components of a central executive, influences the speaking rate of these talkers. Implications for therapies designed to increase speech fluency in CI recipients are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21644795.

Tongue pressure waveform analysis for ascertaining the influence of tongue muscle composition on articulation

BACKGROUND

Rate force development is associated with performance and muscle composition in whole-body muscle. Although rate force development on tongue muscle can be examined using tongue pressure waveform, there have been only few investigations on this topic.

OBJECTIVES

This study's main purpose was to investigate the reliability of tongue pressure waveform analysis and its relationship with articulation and tongue muscle composition. In addition, we also investigated the association between tongue muscle composition and articulation.

METHODS

Forty-five community-dwelling individuals aged >20 years participated. We analysed tongue pressure waveform, including maximum tongue pressure (MTP), time to peak, mean rate of tongue force development and peak rate of tongue force development (PRTFD). We also assessed oral diadochokinesis. Magnetic resonance imaging of the tongue provided data on tongue muscle composition, including tongue volume, fat mass, lean muscle mass and fat percentage. We evaluated the reliability of tongue pressure waveform analysis. Moreover, we examined the coefficients between tongue pressure waveform analysis, oral diadochokinesis and tongue composition.

RESULTS

We detected a high reliability of MTP and PRTFD. MTP and PRTFD were significantly correlated with tongue muscle composition. MTP was not significantly correlated with oral diadochokinesis. PRTFD was significantly positively correlated with oral diadochokinesis. Tongue fat mass and fat percentage were negatively correlated with oral diadochokinesis of /ta/ and /ka/.

CONCLUSIONS

Peak rate of tongue force development is a highly reliable method for tongue pressure analysis and is useful for elucidating the functional importance of tongue muscle function on articulation. We speculated that fatty infiltration of the tongue adversely affects articulation.

The relation of poor mastication with cognition and dementia risk: a population-based longitudinal study

We investigated the effect of poor masticatory ability on cognitive trajectories and dementia risk in older adults. 544 cognitively intact adults aged ≥50 were followed for up to 22 years. Cognitive domains (verbal, spatial/fluid, memory, and perceptual speed) were assessed at baseline and follow-ups. Dementia was ascertained according to standard criteria. Masticatory ability was assessed using the Eichner Index and categorized according to the number of posterior occlusal zones: A (all four), B (3-1), and C (none).

At baseline, 147 (27.0%) participants were in Eichner category A, 169 (31.1%) in B and 228 (41.9%) in C. After the age of 65, participants in Eichner category B and C showed an accelerated decline in spatial/fluid abilities (β: -0.16, 95% CI: -0.30 to -0.03) and (β: -0.15, 95% CI: -0.28 to -0.02), respectively. Over the follow-up, 52 incident dementia cases were identified. Eichner categories B or C were not associated with an increased risk of dementia, compared to category A (Hazard Ratio [HR]: 0.83, 95% CI: 0.39 to 1.76 and HR: 0.63, 95% CI: 0.30 to 1.29, respectively).

Poor masticatory ability is associated with an accelerated cognitive decline in fluid/spatial abilities, however it was not related to a higher risk of dementia.

Cognitive Load Affects Speech Motor Performance Differently in Older and Younger Adults

Purpose The aim of this study was to determine the impact of cognitive load imposed by a speech production task on the speech motor performance of healthy older and younger adults. Response inhibition, selective attention, and working memory were the primary cognitive processes of interest. Method Twelve healthy older and 12 healthy younger adults produced multiple repetitions of 4 sentences containing an embedded Stroop task in 2 cognitive load conditions: congruent and incongruent. The incongruent condition, which required participants to suppress orthographic information to say the font colors in which color words were written, represented an increase in cognitive load relative to the congruent condition in which word text and font color matched. Kinematic measures of articulatory coordination variability and movement duration as well as a behavioral measure of sentence production accuracy were compared between groups and conditions and across 3 sentence segments (pre-, during-, and post-Stroop). Results Increased cognitive load in the incongruent condition was associated with increased articulatory coordination variability and movement duration, compared to the congruent Stroop condition, for both age groups. Overall, the effect of increased cognitive load was greater for older adults than younger adults and was greatest in the portion of the sentence in which cognitive load was manipulated (during-Stroop), followed by the pre-Stroop segment. Sentence production accuracy was reduced for older adults in the incongruent condition. Conclusions Increased cognitive load involving response inhibition, selective attention, and working memory processes within a speech production task disrupted both the stability and timing with which speech was produced by both age groups. Older adults' speech motor performance may have been more affected due to age-related changes in cognitive and motoric functions that result in altered motor cognition.

Reference values of maximum performance tests of speech production

PURPOSE

Maximum performance tests examine upper limits of speech motor performance, as used by speech-language pathologists in dysarthria assessment protocols. The Radboud Dysarthria Assessment includes maximum repetition rate, maximum phonation time, fundamental frequency range and maximum phonation volume to assist in detecting pathological performance. This study aims to obtain reference values for each of these tests.

METHOD

A group of 224 healthy Dutch adults aged 18-80 years performed the maximum performance tests. Age, sex, body height, smoking habit, and profession were registered. Using multivariable linear regression, a wide range of models was tested to examine the relationship between these person characteristics and speech performance. The likelihood ratio was used to test the goodness of fit to the data.

RESULT

Above 60 years of age, maximum repetition rate, fundamental frequency range and maximum phonation volume were all negatively affected by age. Below 60 years, only women showed effects of age on fundamental frequency range (increase) and maximum phonation volume (decrease). Maximum phonation time was primarily related to body height (increase).

CONCLUSION

This study presents reference values of four maximum performance tests for comparing the performance of dysarthric patients with non-pathological performance. Age was identified as most important factor influencing maximum speech performance.

An examination of the language construct in NIMH's research domain criteria: Time for reconceptualization!

The National Institute of Mental Health's Research Domain Criteria (RDoC) Initiative "calls for the development of new ways of classifying psychopathology based on dimensions of observable behavior." As a result of this ambitious initiative, language has been identified as an independent construct in the RDoC matrix. In this article, we frame language within an evolutionary and neuropsychological context and discuss some of the limitations to the current measurements of language. Findings from genomics and the neuroimaging of performance during language tasks are discussed in relation to serious mental illness and within the context of caveats regarding measuring language. Indeed, the data collection and analysis methods employed to assay language have been both aided and constrained by the available technologies, methodologies, and conceptual definitions. Consequently, different fields of language research show inconsistent definitions of language that have become increasingly broad over time. Individually, they have also shown significant improvements in conceptual resolution, as well as in experimental and analytic techniques. More recently, language research has embraced collaborations across disciplines, notably neuroscience, cognitive science, and computational linguistics and has ultimately re-defined classical ideas of language. As we move forward, the new models of language with their remarkably multifaceted constructs force a re-examination of the NIMH RDoC conceptualization of language and thus the neuroscience and genetics underlying this concept. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Effects of age and syntactic complexity on speech motor performance

PURPOSE

This study investigated the effect of age on articulatory movement and stability in young, middle-age, and older adults. It also examined the potential influence of linguistic complexity on speech motor control across utterances that differed in their length and grammatical complexity.

METHOD

There were 60 participants in 3 age groups: 20-30 years, 40-50 years, and 60-70 years, with equal numbers of men and women in each group. The speakers produced 10 repetitions of 5 different stimuli-each of which included the same bilabial-loaded phrase in different grammatical contexts-while their lip movements were recorded.

RESULTS

Participants from the 60-year-old group had significantly longer utterance durations, whereas those from the 20-year-old group had the highest jaw spatiotemporal index (STI) values. There were significant differences in the upper lip STI, displacement, and velocity as well as in vocal intensity for the longer, complex conditions compared with the shorter, phrase-only task. Overall, the differences in performance were minimal across grammatical complexity levels that were equal in length.

CONCLUSION

These findings suggest that speech motor control matures beyond young adulthood and that linguistic complexity in a repetitive task does not appear to have a consistent effect on measures of speech movement.