Cross-Cultural Adaptation, Validation, and Diagnostic Accuracy of the Voice Fatigue Handicap Questionnaire-Persian Version.

OBJECTIVE: The current study aimed to determine the psychometric characteristics of a translated version of the Voice Fatigue Handicap Questionnaire in Persian by examining the validity, reliability, and diagnostic accuracy using data collected from people with and without dysphonia. STUDY DESIGN: Cross-sectional study. METHOD: The original questionnaire was translated from Italian to Persian using the International Quality of Life Assessment criteria. The translated version was completed by 122 people with dysphonia and 49 people without dysphonia. The validity, reliability, and diagnostic accuracy of the Voice Fatigue Handicap Questionnaire Persian-version were evaluated. A panel of five voice-specializing Speech and Language Pathologists and 20 native Persian speakers (with dysphonia) in a pilot study confirmed the translated version for content and face validity, respectively. The internal consistency was evaluated by Cronbach's alpha and McDonald omega coefficients. The intraclass correlation coefficient was used to examine the test-retest reliability. For discriminant validity, the mean total and subscale scores of respondents with and without dysphonia were compared through independent t tests. Finally, sensitivity, specificity, and ideal cut-off value were determined using the receiver-operating characteristic curve. RESULTS: Cronbach's alpha coefficient was 0.965 for the total score (functional: α = 0.883, emotional: α = 0.944, physical: α = 0.917). Also, the McDonald omega coefficient was 0.966 for the total score (functional: ω = 0.889, emotional: ω = 0.933, physical: ω = 0.920). The intraclass correlation coefficient for measuring the test-retest reliability was 0.971 for the total score (functional: ICC=0.937, emotional: ICC=0.954, physical ICC=0.976). The results of the independent samples t tests indicated that the dysphonia group obtained significantly higher mean scores (total and subscale scores) than the group without dysphonia. The cutoff value of 13.5 was determined based on the optimal balance of sensitivity (0.992) and specificity (0.918). CONCLUSION: The Voice Fatigue Handicap Questionnaire-Persian version is a valid and reliable questionnaire to identify individuals at high risk of vocal fatigue and subsequent dysphonia.

Order Affects Clear and Loud Speech Response.

PURPOSE: The purpose of this investigation was to examine the impact of instruction order on the speech production response when adopting higher effort speaking styles, specifically loud and clear speech. METHOD: Speech intensity, lip aperture range, and speech rate data were collected from 24 talkers who repeated the utterance "Buy Bobby a puppy" using habitual, clear, and loud speech. Participants were assigned in quasi-random fashion to one of two groups: a Clear-Loud Group (11 participants; order: habitual-clear-loud) or a Loud-Clear Group (13 participants; order: habitual-loud-clear). RESULTS: Talkers in the Clear-Loud Group exhibited higher speech intensity during the loud style compared with those who performed the Loud-Clear Group. Furthermore, talkers in the Clear-Loud Group retained the increases lip aperture range and reductions in speech rate associated with the clear style when producing the loud style. Conversely, talkers in the Loud-Clear Group exhibited significant increases in lip aperture range between the habitual and loud styles and between the loud and clear styles. Additionally, the Loud-Clear Group exhibited a reduction in speech rate only during the clear style, as no differences in speech rate were observed between the habitual and loud styles. CONCLUSIONS: These findings may suggest that producing a higher effort style leads to carry-over effects in subsequent styles. Future research should investigate factors that moderate the degree of order effects for both research and clinical purposes. For instance, if generalizable, the compounding carry-over effects may prove advantageous for certain clinical populations.

Effect of clear speech on acoustic measures of dysprosody in Parkinson disease for different reading tasks.

PURPOSE: The purpose of the study was to determine the effect of clear speech instruction on acoustic measures of dysprosody between reading passages of differing linguistic content for speakers with and without Parkinson Disease (PD). METHOD: Ten speakers with PD and 10 controls served as participants and read five simple and three standard reading stimuli twice. First, speakers read habitually and then following clear speech instruction. Acoustic measures of fundamental frequency variation (semitone standard deviation, STSD), articulation rate, and between-complex pause durations were calculated. RESULT: Results indicated speakers with PD exhibited less fundamental frequency variation than controls across reading stimuli and instructions. All speakers exhibited lower STSD and longer between-complex pause durations for the standard compared to simple reading stimuli. For clear speech, all speakers reduced articulation rate and increased between-complex pause durations in both simple and standard reading stimuli. However, speakers with PD exhibited a significantly less robust reduction in articulation rate for clear speech than control speakers for all reading stimuli. CONCLUSION: Linguistic content of reading stimuli contributes to differences in fundamental frequency variation and pause duration for all speakers. All speakers reduced articulation rate for clear speech compared to habitual instruction, but speakers with PD did so to a lesser extent than controls. Linguistic content of reading stimuli to examine dysprosody in PD should be considered for clinical application.

Development of epistatic YES and AND protein logic gates and their assembly into signalling cascades.

The construction and assembly of artificial allosteric protein switches into information and energy processing networks connected to both biological and non-biological systems is a central goal of synthetic biology and bionanotechnology. However, designing protein switches with the desired input, output and performance parameters is challenging. Here we use a range of reporter proteins to demonstrate that their chimeras with duplicated receptor domains produce YES gate protein switches with large (up to 9,000-fold) dynamic ranges and fast (minutes) response rates. In such switches, the epistatic interactions between largely independent synthetic allosteric sites result in an OFF state with minimal background noise. We used YES gate protein switches based on ß-lactamase to develop quantitative biosensors of therapeutic drugs and protein biomarkers. Furthermore, we demonstrated the reconfiguration of YES gate switches into AND gate switches controlled by two different inputs, and their assembly into signalling networks regulated at multiple nodes.

Reliability of a Linguistic Segmentation Procedure Specified by Systemic Functional Linguistics to Examine Extemporaneous Speech.

PURPOSE: Extemporaneous speech tasks provide an ecologically valid sample to examine speech acoustics, but differing methodologies exist in the literature for segmentation. Therefore, the purpose of this study was to examine the utility and reliability of a segmentation approach for extemporaneous speech specified by systemic functional linguistics (SFL) and its potential research and clinical applications. METHOD: Ten speakers without communication disorders served as participants in this study, and they responded to self-selected extemporaneous speaking prompts. Two expert analysts and one clinician analyst utilized a segmentation procedure specified by SFL to segment the extemporaneous speech samples into clauses and clause complexes. Intra- and interrater reliability were calculated for each analyst and pair of analysts. Acoustic measures of duration, speech rate, and intercomplex pause durations were calculated for each clause complex. RESULTS: Analyses for both intra- and interrater reliability revealed high percent agreement that was significantly greater than chance for expert and clinician analysts and between each pair of analysts (p < .001). Acoustic analyses revealed expected variation in number and duration of spoken syllables of clause complexes between and within speakers. CONCLUSIONS: The segmentation approach for extemporaneous speech specified by SFL is a reliable method for trained analysts that is informed by lexico-grammar and allows for acoustic measurement of speech production. It is also a reliable method for clinician analysts for speakers without communication disorders, and future work will investigate its utility for speakers with motor speech disorders. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.22357138.

Quantifying Spatial and Temporal Variability of Clear and Loud Speech Produced While Performing a Concurrent Visuomotor Task.

PURPOSE: The purpose of this research note was to quantify the impact of concurrent performance of an attention-demanding secondary task on utterance-to-utterance movement variability associated with higher effort speaking styles, namely, clear and loud speech. METHOD: Lip and jaw kinematics collected as part of a prior study were analyzed. Participants repeated "Buy Bobby a puppy" using habitual, loud, and clear speech styles in isolation and while performing a secondary tracking task. The lip aperture (LA) signal was segmented based on opening and closing gestures associated with the utterance. The standard deviation of each segment duration was calculated to quantify temporal variability. To quantify spatial variability, each segment was first time normalized. The mean standard deviation of the overlapping time-normalized LA amplitudes was computed for each segment from the repetitions produced in each speech style and condition (speaking in isolation vs. speaking while tracking). A relative measure of spatial variation was also computed to account for the potential impact of articulatory scaling. RESULTS: Clear speech was associated with greater temporal and spatial variability than the habitual and loud styles. In the habitual style, talkers also exhibited a slight reduction in absolute spatial variability when speaking while tracking compared to speaking in isolation. The reduction in absolute spatial variability was likely associated with the concomitant reduction in LA range of motion, as there was no change in the relative spatial variability between conditions. CONCLUSION: The current investigation expands prior work by quantifying spatial and temporal characteristics of different speaking styles performed in isolation and while concurrently performing an attention-demanding visuomotor task.

Prolonged Processing Time for Manual and Vocal Responses in Parkinson Disease: A Psychological Refractory Period Paradigm Study.

PURPOSE: The purpose of this study was to examine a potential increased cognitive processing bottleneck within Parkinson disease (PD) by extending a previous overlapping task methodology. Additionally, this study extends previous overlapping task methodology in PD to examine the influence of modality (vocal vs. manual) on response delays in overlapping tasks in PD. METHOD: This study used the psychological refractory period (PRP) paradigm (overlapping-task paradigm) to study processing limitations as participants complete two tasks that increasingly overlap in time. Three levels of temporal overlap of tasks were utilized to vary cognitive demands on manual and vocal response time tasks. Ten participants with PD (PwPD) and 12 participants without PD were included in this study. RESULTS: Participants with PD demonstrated response time delays across temporal overlap conditions (likely indicating motor deficits) along with a larger increase in response delays in the most overlapped, cognitively taxing condition (likely indicating longer central processing bottleneck). Additionally, modality did not influence response times differently in overlapping task conditions or within participant groups. CONCLUSION: An extension of previous overlapping task methodologies within a complex task was successful in demonstrating an increased central processing deficit across manual and vocal response delays in PD, regardless of modality of response.

Systemic Racism in Communication Sciences and Disorders Academic Programs: A Commentary on Trends in Racial Representation.

PURPOSE: As a discipline, communication sciences and disorders (CSD) has struggled to address equity and inclusion for students, professionals, and scholars from historically excluded racial groups. Recent publications in this periodical that have begun to confront systemic racism in the discipline have been met with some expected resistance. In this commentary, I attempt to support and expand an argument made by Ellis and Kendall (2021), namely, that systemic racism has been and continues to be a normal and persistent feature of our academic programs. A comparison to U.S. Census data suggests that Asian, Black, Indigenous, Native, Latino/a/e, and multiracial CSD professionals are represented to a drastically lower rate compared with their representation in the population at large. Furthermore, publicly available data summaries indicate that there is a reduction in the level of racial diversity that is associated with an increase in White representation across the entire progression of the professional training and certification process, with the greatest level of diversity at the undergraduate level followed by the graduate and professional levels. CONCLUSIONS: A general knowledge of social and legal history in the United States would suggest that the relative reduction in representation across the academic and professional levels of the CSD disciplines results from policy and practice patterns that serve to preserve a White-dominant culture in our profession and exclude People of Color. Continued efforts broadly based in critical race studies may prove as a useful tool to identify, confront, and transform current policy and practice patterns in our national organization, academic programs, and accrediting bodies that have produced and sustained levels of inequality and White dominance in our programs and disciplines.

Over the rainbow: structural characterization of the chromoproteins gfasPurple, amilCP, spisPink and eforRed.

Anthozoan chromoproteins are highly pigmented, diversely coloured and readily produced in recombinant expression systems. While they are a versatile and powerful building block in synthetic biology for applications such as biosensor development, they are not widely used in comparison to the related fluorescent proteins, partly due to a lack of structural characterization to aid protein engineering. Here, high-resolution X-ray crystal structures of four open-source chromoproteins, gfasPurple, amilCP, spisPink and eforRed, are presented. These proteins are dimers in solution, and mutation at the conserved dimer interface leads to loss of visible colour development in gfasPurple. The chromophores are trans and noncoplanar in gfasPurple, amilCP and spisPink, while that in eforRed is cis and noncoplanar, and also emits fluorescence. Like other characterized chromoproteins, gfasPurple, amilCP and eforRed contain an sp2-hybridized N-acylimine in the peptide bond preceding the chromophore, while spisPink is unusual and demonstrates a true sp3-hybridized trans-peptide bond at this position. It was found that point mutations at the chromophore-binding site in gfasPurple that substitute similar amino acids to those in amilCP and spisPink generate similar colours. These features and observations have implications for the utility of these chromoproteins in protein engineering and synthetic biology applications.

The transmembrane adapter SCIMP recruits tyrosine kinase Syk to phosphorylate Toll-like receptors to mediate selective inflammatory outputs.

Innate immune signaling by Toll-like receptors (TLRs) involves receptor phosphorylation, which helps to shape and drive key inflammatory outputs, yet our understanding of the kinases and mechanisms that mediate TLR phosphorylation is incomplete. Spleen tyrosine kinase (Syk) is a nonreceptor protein tyrosine kinase, which is known to relay adaptive and innate immune signaling, including from TLRs. However, TLRs do not contain the conserved dual immunoreceptor tyrosine-based activation motifs that typically recruit Syk to many other receptors. One possibility is that the Syk-TLR association is indirect, relying on an intermediary scaffolding protein. We previously identified a role for the palmitoylated transmembrane adapter protein SCIMP in scaffolding the Src tyrosine kinase Lyn, for TLR phosphorylation, but the role of SCIMP in mediating the interaction between Syk and TLRs has not yet been investigated. Here, we show that SCIMP recruits Syk in response to lipopolysaccharide-mediated TLR4 activation. We also show that Syk contributes to the phosphorylation of SCIMP and TLR4 to enhance their binding. Further evidence pinpoints two specific phosphorylation sites in SCIMP critical for its interaction with Syk-SH2 domains in the absence of immunoreceptor tyrosine-based activation motifs. Finally, using inhibitors and primary macrophages from SCIMP-/- mice, we confirm a functional role for SCIMP-mediated Syk interaction in modulating TLR4 phosphorylation, signaling, and cytokine outputs. In conclusion, we identify SCIMP as a novel, immune-specific Syk scaffold, which can contribute to inflammation through selective TLR-driven inflammatory responses.

A Rationally and Computationally Designed Fluorescent Biosensor for d-Serine.

Solute-binding proteins (SBPs) have evolved to balance the demands of ligand affinity, thermostability, and conformational change to accomplish diverse functions in small molecule transport, sensing, and chemotaxis. Although the ligand-induced conformational changes that occur in SBPs make them useful components in biosensors, they are challenging targets for protein engineering and design. Here, we have engineered a d-alanine-specific SBP into a fluorescence biosensor with specificity for the signaling molecule d-serine (D-serFS). This was achieved through binding site and remote mutations that improved affinity (KD = 6.7 ± 0.5 µM), specificity (40-fold increase vs glycine), thermostability (Tm = 79 °C), and dynamic range (∼14%). This sensor allowed measurement of physiologically relevant changes in d-serine concentration using two-photon excitation fluorescence microscopy in rat brain hippocampal slices. This work illustrates the functional trade-offs between protein dynamics, ligand affinity, and thermostability and how these must be balanced to achieve desirable activities in the engineering of complex, dynamic proteins.

Connecting Artificial Proteolytic and Electrochemical Signaling Systems with Caged Messenger Peptides.

Enzymatic polypeptide proteolysis is a widespread and powerful biological control mechanism. Over the last few years, substantial progress has been made in creating artificial proteolytic systems where an input of choice modulates the protease activity and thereby the activity of its substrates. However, all proteolytic systems developed so far have relied on the direct proteolytic cleavage of their effectors. Here, we propose a new concept where protease biosensors with a tunable input uncage a signaling peptide, which can then transmit a signal to an allosteric protein reporter. We demonstrate that both the cage and the regulatory domain of the reporter can be constructed from the same peptide-binding domain, such as calmodulin. To demonstrate this concept, we constructed a proteolytic rapamycin biosensor and demonstrated its quantitative actuation on fluorescent, luminescent, and electrochemical reporters. Using the latter, we constructed sensitive bioelectrodes that detect the messenger peptide release and quantitatively convert the recognition event into electric current. We discuss the application of such systems for the construction of in vitro sensory arrays and in vivo signaling circuits.

Practice Mediates Bidirectional Dual-Task Interference When Performing a Novel Sequential Nonword Repetition Task.

Introduction The current study examined the extent to which practice amount mediates dual-task interference patterns associated with concurrent performance of a novel speech task and attention-demanding visuomotor task. Method A Sequential Nonword Repetition Task was used to examine the effect of practice on interference associated with concurrent performance of a Visuomotor Pursuit Task. Twenty-five young adult participants were assigned to either an Extended Practice Group or a Limited Practice Group and performed a novel Sequential Nonword Repetition Task in isolation and while performing a concurrent visuomotor pursuit rotor task. Results Participants in the Limited Practice Group who were afforded a limited amount of practice exhibited dual-task interference (i.e., dual-task performance reductions) for both the speech and visuomotor tasks (i.e., bidirectional dual-task interference). Conversely, participants in the Extended Practice Group who were afforded extended practice exhibited little-to-no observable dual-task interference on the nonword repetition task. Conclusion Data from the current investigation suggest that the amount of initial practice mediates the degree of dual-task interference observed when a novel speech production task is performed with an attention-demanding Visuomotor Pursuit Task. Supplemental Material https://doi.org/10.23641/asha.14608071.

Tracking the Costs of Clear and Loud Speech: Interactions Between Speech Motor Control and Concurrent Visuomotor Tracking.

Purpose Prior work has demonstrated that competing tasks impact habitual speech production. The purpose of this investigation was to quantify the extent to which clear and loud speech are affected by concurrent performance of an attention-demanding task. Method Speech kinematics and acoustics were collected while participants spoke using habitual, loud, and clear speech styles. The styles were performed in isolation and while performing a secondary tracking task. Results Compared to the habitual style, speakers exhibited expected increases in lip aperture range of motion and speech intensity for the clear and loud styles. During concurrent visuomotor tracking, there was a decrease in lip aperture range of motion and speech intensity for the habitual style. Tracking performance during habitual speech did not differ from single-task tracking. For loud and clear speech, speakers retained the gains in speech intensity and range of motion, respectively, while concurrently tracking. A reduction in tracking performance was observed during concurrent loud and clear speech, compared to tracking alone. Conclusions These data suggest that loud and clear speech may help to mitigate motor interference associated with concurrent performance of an attention-demanding task. Additionally, reductions in tracking accuracy observed during concurrent loud and clear speech may suggest that these higher effort speaking styles require greater attentional resources than habitual speech.

Rational Design of Novel Fluorescent Enzyme Biosensors for Direct Detection of Strigolactones.

Strigolactones are plant hormones and rhizosphere signaling molecules with key roles in plant development, mycorrhizal fungal symbioses, and plant parasitism. Currently, sensitive, specific, and high-throughput methods of detecting strigolactones are limited. Here, we developed genetically encoded fluorescent strigolactone biosensors based on the strigolactone receptors DAD2 from Petunia hybrida, and HTL7 from Striga hermonthica. The biosensors were constructed via domain insertion of circularly permuted GFP. The biosensors exhibited loss of cpGFP fluorescence in vitro upon treatment with the strigolactones 5-deoxystrigol and orobanchol, or the strigolactone analogue rac-GR24, and the ShHTL7 biosensor also responded to a specific antagonist. To overcome biosensor sensitivity to changes in expression level and protein degradation, an additional strigolactone-insensitive fluorophore, LSSmOrange, was included as an internal normalization control. Other plant hormones and karrikins resulted in no fluorescence change, demonstrating that the biosensors report on compounds that specifically bind the SL receptors. The DAD2 biosensor likewise responded to strigolactones in an in vivo protoplast system, and retained strigolactone hydrolysis activity. These biosensors have applications in high-throughput screening for agrochemical compounds, and may also have utility in understanding strigolactone mediated signaling in plants.

Comprehensive analysis of IncC plasmid conjugation identifies a crucial role for the transcriptional regulator AcaB.

The IncC family of broad-host-range plasmids enables the spread of antibiotic resistance genes among human enteric pathogens1-3. Although aspects of IncC plasmid conjugation have been well studied4-9, many roles of conjugation genes have been assigned based solely on sequence similarity. We applied hypersaturated transposon mutagenesis and transposon-directed insertion-site sequencing to determine the set of genes required for IncC conjugation. We identified 27 conjugation genes, comprising 19 that were previously identified (including two regulatory genes, acaDC) and eight not previously associated with conjugation. We show that one previously unknown gene, acaB, encodes a transcriptional regulator that has a crucial role in the regulation of IncC conjugation. AcaB binds upstream of the acaDC promoter to increase acaDC transcription; in turn, AcaDC activates the transcription of IncC conjugation genes. We solved the crystal structure of AcaB at 2.9-Å resolution and used this to guide functional analyses that reveal how AcaB binds to DNA. This improved understanding of IncC conjugation provides a basis for the development of new approaches to reduce the spread of these multi-drug-resistance plasmids.

Caged Activators of Artificial Allosteric Protein Biosensors.

The ability of proteins to interconvert unrelated biochemical inputs and outputs underlays most energy and information processing in biology. A common conversion mechanism involves a conformational change of a protein receptor in response to a ligand binding or a covalent modification, leading to allosteric activity modulation of the effector domain. Designing such systems rationally is a central goal of synthetic biology and protein engineering. A two-component sensory system based on the scaffolding of modules in the presence of an analyte is one of the most generalizable biosensor architectures. An inherent problem of such systems is dependence of the response on the absolute and relative concentrations of the components. Here we use the example of two-component sensory systems based on calmodulin-operated synthetic switches to analyze and address this issue. We constructed "caged" versions of the activating domain thereby creating a thermodynamic barrier for spontaneous activation of the system. We demonstrate that the caged biosensor architectures could operate at concentrations spanning 3 orders of magnitude and are applicable to electrochemical, luminescent, and fluorescent two-component biosensors. We analyzed the activation kinetics of the caged biosensors and determined that the core allosteric switch is likely to be the rate limiting component of the system. These findings provide guidance for predictable engineering of robust sensory systems with inputs and outputs of choice.

Effect of Clear Speech on the Duration of Silent Intervals at Syntactic and Phonemic Boundaries in the Speech of Individuals With Parkinson Disease.

Purpose The purpose of the current investigation was to determine the extent to which individuals with and without Parkinson disease (PD) modified silent interval durations when using a clear speaking style. Method Ten individuals with idiopathic PD and 10 older adult control speakers produced a reading passage using both habitual and clear speaking styles. Silent intervals lasting 15 ms and longer were identified and extracted. Each silent interval was categorized according to the surrounding syntactic context of the reading passage. In addition, voiceless stop gaps that occurred within words, phrases, or clauses were categorized by the preceding phonemic context. Results Statistical analyses revealed that all participants increased silent interval duration with a clear speaking style at inter-sentence and intra-sentence syntactic boundaries. Compared to controls, individuals with PD exhibited significantly less increase in silent interval durations at these syntactic boundaries. Control speakers also increased silent stop gap durations in the clear speaking style regardless of preceding phonemic context. Individuals with PD, however, only increased stop gap duration when the silent interval was preceded by a sonorant. Conclusion These findings suggest that speakers with PD exhibit less clarity-related increase in silent interval duration than control speakers. In addition, speakers with PD exhibited significant increases in silent interval duration that coincided with syntactic boundaries of the reading passage but little to no clarity-related modulation of stop gap intervals. Therefore, these data suggest that speakers with PD exhibited changes in silent interval durations that were more so associated with modulation of speech prosody than articulation when using a clearer speaking style.

Examination of Clear Speech in Parkinson Disease Using Measures of Working Vowel Space.

Purpose The purpose of the current study was to characterize clear speech production for speakers with and without Parkinson disease (PD) using several measures of working vowel space computed from frequently sampled formant trajectories. Method The 1st 2 formant frequencies were tracked for a reading passage that was produced using habitual and clear speaking styles by 15 speakers with PD and 15 healthy control speakers. Vowel space metrics were calculated from the distribution of frequently sampled formant frequency tracks, including vowel space hull area, articulatory-acoustic vowel space, and multiple vowel space density (VSD) measures based on different percentile contours of the formant density distribution. Results Both speaker groups exhibited significant increases in the articulatory-acoustic vowel space and VSD10, the area of the outermost (10th percentile) contour of the formant density distribution, from habitual to clear styles. These clarity-related vowel space increases were significantly smaller for speakers with PD than controls. Both groups also exhibited a significant increase in vowel space hull area; however, this metric was not sensitive to differences in the clear speech response between groups. Relative to healthy controls, speakers with PD exhibited a significantly smaller VSD90, the area of the most central (90th percentile), densely populated region of the formant space. Conclusions Using vowel space metrics calculated from formant traces of the reading passage, the current work suggests that speakers with PD do indeed reach the more peripheral regions of the vowel space during connected speech but spend a larger percentage of the time in more central regions of formant space than healthy speakers. Additionally, working vowel space metrics based on the distribution of formant data suggested that speakers with PD exhibited less of a clarity-related increase in formant space than controls, a trend that was not observed for perimeter-based measures of vowel space area.

Effects of Concurrent Manual Task Performance on Connected Speech Acoustics in Individuals With Parkinson Disease.

Purpose Prior investigations suggest that simultaneous performance of more than 1 motor-oriented task may exacerbate speech motor deficits in individuals with Parkinson disease (PD). The purpose of the current investigation was to examine the extent to which performing a low-demand manual task affected the connected speech in individuals with and without PD. Method Individuals with PD and neurologically healthy controls performed speech tasks (reading and extemporaneous speech tasks) and an oscillatory manual task (a counterclockwise circle-drawing task) in isolation (single-task condition) and concurrently (dual-task condition). Results Relative to speech task performance, no changes in speech acoustics were observed for either group when the low-demand motor task was performed with the concurrent reading tasks. Speakers with PD exhibited a significant decrease in pause duration between the single-task (speech only) and dual-task conditions for the extemporaneous speech task, whereas control participants did not exhibit changes in any speech production variable between the single- and dual-task conditions. Conclusions Overall, there were little to no changes in speech production when a low-demand oscillatory motor task was performed with concurrent reading. For the extemporaneous task, however, individuals with PD exhibited significant changes when the speech and manual tasks were performed concurrently, a pattern that was not observed for control speakers. Supplemental Material https://doi.org/10.23641/asha.8637008.