Slow Firing Single Units Are Essential for Optimal Decoding of Silent Speech

Summary The motivation of someone who is locked-in, that is, paralyzed and mute, is to find relief for their loss of function. The data presented in this report is part of an attempt to restore one of those lost functions, namely, speech. An essential feature of the development of a speech prosthetic is optimal decoding of patterns of recorded neural signals during silent or covert speech, that is, speaking ‘inside the head’ with no audible output due to the paralysis of the articulators. The aim of this paper is to illustrate the importance of both fast and slow single unit firings recorded from an individual with locked-in syndrome and from an intact participant speaking silently. Long duration electrodes were implanted in the motor speech cortex for up to 13 years in the locked-in participant. The data herein provide evidence that slow firing single units are essential for optimal decoding accuracy. Additional evidence indicates that slow firing single units can be conditioned in the locked-in participant five years after implantation, further supporting their role in decoding.

Beyond Broca: Neural Architecture and Evolution of a Dual Motor Speech Coordination System

Classical neural architecture models of speech production propose a single system coordinating all the vocal articulators from lips to larynx. Here we propose a dual coordination system in which laryngeal control of pitch-related aspects of prosody and song are controlled by a dorsal premotor system while supralaryngeal articulation at the phonetic/syllabic level is controlled by a ventral premotor system. The separability of these neural systems supports models of the evolution of speech and language in which song-based communication was an early foundational stage.

Visualizing the Knowledge Domain of Motor Speech Disorders: A Scientific Review (2000-2019)

This review visualizes the knowledge domain of motor speech disorders (MSDs) in linguistics between 2000 and 2019 by means of scientometric methods. With topic searches, the study collected 869 bibliographic records and 20, 411 references from Web of Science Core Collection (WoSCC) of Thomson Reuter. The clustered and visualized document co-citation network of the MSDs knowledge domain in CiteSpace identifies 15 research foci in different periods, including apraxia of speech, acoustics, children, technology, aphemia, childhood apraxia of speech, primary progressive aphasia, speech motor delay, Parkinson’s disease, amyotrophic lateral sclerosis, rhythm, foreign accent syndrome, phonation, phonological awareness, dose and speech perception. Revolving around linguistics, these foci could be divided into studies on speech characteristics of MSDs in terms of phonology and phonetics, remedies for MSDs in terms of neurolinguistics and acoustic phonetics, dysarthria secondary to neurological diseases based on pathological linguistics, subtypes of apraxia of speech, methods of MSDs based on auditory phonetics and a newly recognized subtype of MSDs. Meanwhile, the emerging trends of MSDs in linguistics are detected by the analysis of reference citation bursts, suggesting growing research in remedies for MSDs with the focus on assessments and effectiveness of treatments, speech characteristics and indexes of dysarthria secondary to neurological diseases and assistance to diagnose apraxia of speech. To sum up, the review has indicated that the acoustic measures to assess MSDs and acoustic remedies for dysarthria may not only be the past foci but also be future trends.

Focal Cognitive Syndromes

The neurologic results of cortical lesions reflect the structural properties of the affected region. Lesions affecting primary sensorimotor cortices result in primary sensorimotor deficits that are qualitatively all-or-nothing, such as blindness (hemianopia) and paralysis (hemiparesis). Quantitatively, though, the severity of the deficit depends on the extent of the lesion (so that a hemiparetic patient may not be completely paralyzed but simply weak). Lesions affecting modality-specific association regions result in conceptually more complex disorders that are confined to a single modality, such as nonfluent aphasia (a form of motor speech disorder reflecting the language-dominant hemisphere) or prosopagnosia (a visual disorder impairing the ability to disambiguate visually similar entities, specifically faces, reflecting the “what” visual pathway in inferotemporal cortices).

Psychometric Properties of Rapid Word-Based Rate Measures in the Assessment of Bulbar Amyotrophic Lateral Sclerosis: Comparisons With Syllable-Based Rate Tasks

Purpose Rapid maximum performance repetition tasks have increasingly demonstrated their utility as clinimetric markers supporting diagnosis and monitoring of bulbar disease in amyotrophic lateral sclerosis (ALS). A recently developed protocol uses novel real-word repetitions instead of traditional nonword/syllable sequences in hopes of improving sensitivity to motor speech impairments by adding a phonological target constraint that would activate a greater expanse of the motor speech neuroanatomy. This study established the psychometric properties of this novel clinimetric protocol in its assessment of bulbar ALS and compared performance to traditional syllable sequence dysdiadochokinetic (DDK) tasks. Specific objectives were to (a) compare rates between controls and speakers with symptomatic versus presymptomatic bulbar disease, (b) characterize their discriminatory ability in detecting presymptomatic bulbar disease compared to healthy speech, (c) determine their articulatory movement underpinnings, and (d) establish within-individual longitudinal changes. Method DDK and novel tongue (“ticker”—TAR) and labial (“pepper”—LAR) articulatory rates were compared between n = 18 speakers with presymptomatic bulbar disease, n = 10 speakers with symptomatic bulbar disease, and n = 13 healthy controls. Bulbar disease groups were determined by a previously validated speaking rate cutoff. Discriminatory ability was determined using receiver operating characteristic analysis. Within-individual change over time was characterized in a subset of 16 participants with available longitudinal data using linear mixed-effects models. Real-time articulatory movements of the tongue front, tongue dorsum, jaw, and lips were captured using 3-D electromagnetic articulography; effects of movement displacement and speed on clinimetric rates were determined using stepwise linear regressions. Results All clinimetric rates (traditional DDK tasks and novel tasks) were reduced in speakers with symptomatic bulbar disease; only TAR was reduced in speakers with presymptomatic bulbar disease and was able to detect this group with an excellent discrimination ability (area under the curve = 0.83). Kinematic analyses revealed associations with expected articulators, greater motor complexity, and differential articulatory patterns for the novel real-word repetitions than their DDK counterparts. Only LAR significantly declined longitudinally over the disease course. Conclusion Novel real-word clinimetric rate tasks evaluating tongue and labial articulatory dysfunction are valid and effective markers for early detection and tracking of bulbar disease in ALS.

MATHATICS AS PEDAGOGY, IN THE HISTORY OF PEDAGOGY AND EDUCATION

Global paradigms "cover all types of activity and underlie the shift from the deterministic stochastic and to the third synergetic paradigm." The paradigm can be described using three keywords: self-organization, open systems, non-linearity. This work uses the data tabulation method and the graphical presentation of the results. The philosophy of postmodernism is a motor speech between a person and his reality. The value of education is not to memorize facts, to encourage the brain to think. In other words, postmodernism is "a new model of thinking that refuses to embrace traditionalism without reflection and reappraisal." In postmodernism, all similar, different and non-traditional data and knowledge coexist. Thus, if in modernism educational services are important, if they are useful, then in postmodernism the usefulness of a product or service is determined by the emotions of the person for whom the product was created. From this point of view, the educational product and service should be memorable.

(Dys)Prosody in Parkinson’s Disease: Effects of Medication and Disease Duration on Intonation and Prosodic Phrasing

The phonology of prosody has received little attention in studies of motor speech disorders. The present study investigates the phonology of intonation (nuclear contours) and speech chunking (prosodic phrasing) in Parkinson’s disease (PD) as a function of medication intake and duration of the disease. Following methods of the prosodic and intonational phonology frameworks, we examined the ability of 30 PD patients to use intonation categories and prosodic phrasing structures in ways similar to 20 healthy controls to convey similar meanings. Speech data from PD patients were collected before and after a dopaminomimetic drug intake and were phonologically analyzed in relation to nuclear contours and intonational phrasing. Besides medication, disease duration and the presence of motor fluctuations were also factors included in the analyses. Overall, PD patients showed a decreased ability to use nuclear contours and prosodic phrasing. Medication improved intonation regardless of disease duration but did not help with dysprosodic phrasing. In turn, disease duration and motor fluctuations affected phrasing patterns but had no impact on intonation. Our study demonstrated that the phonology of prosody is impaired in PD, and prosodic categories and structures may be differently affected, with implications for the understanding of PD neurophysiology and therapy.