Developmental Change in Variability of Lip Muscle Activity During Speech

2002 ◽  
Vol 45 (6) ◽  
pp. 1077-1087 ◽  
Author(s):  
Amy B. Wohlert ◽  
Anne Smith
Keyword(s):  
Young Adults ◽  
Muscle Activity ◽  
Degrees Of Freedom ◽  
Vocal Tract ◽  
Developmental Change ◽  
Consistent Manner ◽  
Kinematic Studies ◽  
Variability Index ◽  
The Many ◽  
Developing System

Compared to adults, children's speech production measures sometimes show higher trial-to-trial variability in both kinematic and acoustic analyses. A reasonable hypothesis is that this variability reflects variations in neural drive to muscles as the developing system explores different solutions to achieving vocal tract goals. We investigated that hypothesis in the present study by analyzing EMG waveforms produced across repetitions of a phrase spoken by 7-year-olds, 12-year-olds, and young adults. The EMG waveforms recorded via surface electrodes at upper lip sites were clearly modulated in a consistent manner corresponding to lip closure for the bilabial consonants in the utterance. Thus we were able to analyze the amplitude envelope of the rectified EMG with a phrase-level variability index previously used with kinematic data. Both the 7- and 12-year-old children were significantly more variable on repeated productions than the young adults. These results support the idea that children are using varying combinations of muscle activity to achieve phonetic goals. Even at age 12 years, these children were not adult-like in their performance. These and earlier kinematic studies of the oral motor system suggest that children retain their flexibility, employing more degrees of freedom than adults, to dynamically control lip aperture during speech. This strategy is adaptive given the many neurophysiological and biomechanical changes that occur during the transition from adolescence to adulthood.

Articulatory Phonology

2020 ◽  
Author(s):  
Marianne Pouplier
Keyword(s):  
Degrees Of Freedom ◽  
Vocal Tract ◽  
Speech Rate ◽  
Spoken Language ◽  
Articulatory Phonology ◽  
Control Units ◽  
Formidable Challenge ◽  
The Many ◽  
Low Dimensional ◽  
Linguistic Units

One of the most fundamental problems in research on spoken language is to understand how the categorical, systemic knowledge that speakers have in the form of a phonological grammar maps onto the continuous, high-dimensional physical speech act that transmits the linguistic message. The invariant units of phonological analysis have no invariant analogue in the signal—any given phoneme can manifest itself in many possible variants, depending on context, speech rate, utterance position and the like, and the acoustic cues for a given phoneme are spread out over time across multiple linguistic units. Speakers and listeners are highly knowledgeable about the lawfully structured variation in the signal and they skillfully exploit articulatory and acoustic trading relations when speaking and perceiving. For the scientific description of spoken language understanding this association between abstract, discrete categories and continuous speech dynamics remains a formidable challenge. Articulatory Phonology and the associated Task Dynamic model present one particular proposal on how to step up to this challenge using the mathematics of dynamical systems with the central insight being that spoken language is fundamentally based on the production and perception of linguistically defined patterns of motion. In Articulatory Phonology, primitive units of phonological representation are called gestures. Gestures are defined based on linear second order differential equations, giving them inherent spatial and temporal specifications. Gestures control the vocal tract at a macroscopic level, harnessing the many degrees of freedom in the vocal tract into low-dimensional control units. Phonology, in this model, thus directly governs the spatial and temporal orchestration of vocal tract actions.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

Clinical Assessment of Oropharyngeal Motor Development in Young Children

1987 ◽  
Vol 52 (3) ◽  
pp. 271-277 ◽  
Author(s):  
JoAnne Robbins ◽  
Thomas Klee
Keyword(s):  
Clinical Application ◽  
Clinical Assessment ◽  
Motor Development ◽  
Structural Integrity ◽  
Vocal Tract ◽  
Developmental Change ◽  
Clinical Protocol ◽  
Motor Functioning ◽  
Motor Abilities ◽  
Speech Motor

A clinical protocol was developed for the purpose of assessing the oral and speech motor abilities of children. An 86-item test was administered to 90 normally developing children aged 2:6–6:11. Evaluations of the structural integrity of the vocal tract did not show developmental change, although evaluations of oral and speech motor functioning changed significantly with age. The functional portion of the protocol was most sensitive to developmental change up to age 3:6, with an asymptote in performance thereafter. Clinical application of the protocol is discussed.

The immediate effect of foot orthoses on gluteal and lower limb muscle activity during overground walking in healthy young adults

2021 ◽  
Vol 89 ◽  
pp. 102-108
Author(s):  
Adam I. Semciw ◽  
Viji N. Visvalingam ◽  
Charlotte Ganderton ◽  
Peter Lawrenson ◽  
Paul W. Hodges ◽  
...  
Keyword(s):  
Young Adults ◽  
Lower Limb ◽  
Muscle Activity ◽  
Foot Orthoses ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Overground Walking

Anticipatory weight shift between arms when reaching from a crouched posture

2021 ◽  
Author(s):  
Rosemary Gallagher ◽  
Stephaine Perez ◽  
Derek DeLuca ◽  
Isaac L. Kurtzer
Keyword(s):  
Body Weight ◽  
Muscle Activity ◽  
Force Plate ◽  
Vertical Axis ◽  
The Body ◽  
Reaching Movements ◽  
Reactive Control ◽  
Step Initiation ◽  
Weight Shift ◽  
The Many

Reaching movements performed from a crouched body posture require a shift of body weight from both arms to one arm. This situation has remained unexamined despite the analogous load requirements during step initiation and the many studies of reaching from a seated or standing posture. To determine whether the body weight shift involves anticipatory or exclusively reactive control we obtained force plate records, hand kinematics, and arm muscle activity from 11 healthy right-handed participants. They performed reaching movements with their left and right arm in two speed contexts - 'comfortable' and 'as fast as possible' - and two postural contexts - a less stable knees-together posture and more stable knees-apart posture. Weight-shifts involved anticipatory postural actions (APA) by the reaching and stance arms that were opposing in the vertical axis and aligned in the side-to-side axis similar to APAs by the legs for step initiation. Weight-shift APAs were correlated in time and magnitude, present in both speed contexts, more vigorous with the knees placed together, and similar when reaching with the dominant or non-dominant arm. The initial weight-shift was preceded by bursts of muscle activity in the shoulder and elbow extensors (posterior deltoid and triceps lateral) of the reach arm and shoulder flexor (pectoralis major) of the stance arm which indicates their causal role; leg muscles may have indirectly contributed but were not recorded. The strong functional similarity of weight-shift APAs during crouched reaching to human stepping and cats reaching suggests that they are a core feature of posture-movement coordination.

An accurate method to include lubrication forces in numerical simulations of dense Stokesian suspensions

2015 ◽  
Vol 769 ◽  
pp. 369-386 ◽  
Author(s):  
A. Lefebvre-Lepot ◽  
B. Merlet ◽  
T. N. Nguyen
Keyword(s):  
Short Range ◽  
Degrees Of Freedom ◽  
Computational Cost ◽  
Parameter Tuning ◽  
Accurate Method ◽  
Spherical Particles ◽  
Particle Model ◽  
Stokesian Dynamics ◽  
New Feature ◽  
The Many

We address the problem of computing the hydrodynamic forces and torques among $N$ solid spherical particles moving with given rotational and translational velocities in Stokes flow. We consider the original fluid–particle model without introducing new hypotheses or models. Our method includes the singular lubrication interactions which may occur when some particles come close to one another. The main new feature is that short-range interactions are propagated to the whole flow, including accurately the many-body lubrication interactions. The method builds on a pre-existing fluid solver and is flexible with respect to the choice of this solver. The error is the error generated by the fluid solver when computing non-singular flows (i.e. with negligible short-range interactions). Therefore, only a small number of degrees of freedom are required and we obtain very accurate simulations within a reasonable computational cost. Our method is closely related to a method proposed by Sangani & Mo (Phys. Fluids, vol. 6, 1994, pp. 1653–1662) but, in contrast with the latter, it does not require parameter tuning. We compare our method with the Stokesian dynamics of Durlofsky et al. (J. Fluid Mech., vol. 180, 1987, pp. 21–49) and show the higher accuracy of the former (both by analysis and by numerical experiments).

scholarly journals THE DYNAMIC RESPONSE OF OFFSHORE STRUCTURES TO TIME-DEPENDENT FORCES

1964 ◽  
Vol 1 (9) ◽  
pp. 29
Author(s):  
William S. Gaither ◽  
David P. Billington
Keyword(s):  
Degrees Of Freedom ◽  
Wind Waves ◽  
Offshore Structures ◽  
Time Dependent ◽  
Wave Forces ◽  
Ocean Bottom ◽  
Single Wave ◽  
Single Degree Of Freedom ◽  
The Many ◽  
Floating Objects

This paper is addressed to the problem of structural behavior in an offshore environment, and the application of a more rigorous analysis for time-dependent forces than is currently used. Design of pile supported structures subjected to wave forces has, in the past, been treated in two parts; (1) a static analysis based on the loading of a single wave, and (2) a dynamic analysis which sought to determine the resonant frequency by assuming that the structure could be approximated as a single-degree-of-freedom system. (Ref. 4 and 6) The behavior of these structures would be better understood if the dynamic nature of the loading and the many degrees of freedom of the system were included. A structure which is built in the open ocean is subjected to periodic forces due to wind, waves, floating objects, and due occasionally to machinery mounted on the structure. To resist motion, the structure relies on the stiffness of the elements from which it is built and the restraints of the ocean bottom into which the supporting legs are driven.

DEONTOLOGY, THRESHOLDS, AND EFFICIENCY

Legal Theory ◽  
2011 ◽  
Vol 17 (4) ◽  
pp. 301-317 ◽  
Author(s):  
Christopher T. Wonnell
Keyword(s):  
Decision Making ◽  
Degrees Of Freedom ◽  
Moral Judgments ◽  
Rule Following ◽  
Threshold Functions ◽  
Ex Post ◽  
Ex Ante ◽  
The Many ◽  
The Relationship ◽  
Public Decision

This article explores four topics raised by Eyal Zamir and Barak Medina's treatment of constrained deontology. First, it examines whether mathematical threshold functions are the proper way to think about limits on deontology, given the discontinuities of our moral judgments and the desired phenomenology of rule-following. Second, it asks whether constrained deontology is appropriate for public as well as private decision-making, taking issue with the book's conclusion that deontological options are inapplicable to public decision-making, whereas deontological constraints are applicable. Third, it examines the issue of the relationship between deontology and efficiency, asking whether deontological constraints should yield in situations where everyone would expect to benefit from their suspension, either ex ante or ex post. Finally, the article concludes that constrained deontology is susceptible to political abuse because of the many degrees of freedom involved in identifying constrained actions and the point at which those constraints yield to consequentialist benefits.

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