Development of Speech Motor Control in children

2011

2001

A model of the sensorimotor control of speech production is presented. The model is being implemented as a set of computer simulations. It converts an input sequence of discrete phonemes into quasi-continuous motor commands and a sound output. A key feature of the model is that the goals for speech movements, at least for some kinds of sounds, are regions in auditory-temporal space. The model is designed to have properties that are as faithful as possible to data from speakers -including measures of brain function, speech motor control mechanisms, physiology, anatomy, biomechanics and acoustics. Examples of simulations and actual data from some of these domains are presented. The examples demonstrate properties of the model or they are consistent with hypotheses generated from it. Our long-range goal is to implement the model completely and test it exhaustively, in the belief that doing so will significantly advance our understanding of speech motor control.

Journal of Speech, Language, and Hearing Research, 2019

Aphasiology, 2003

Background: Ziegler (2003) reviews neural and behavioural evidence to support a taskdependent model of motor control, whereby motor speech disorders represent impairment of a sensory-motor system specialised for speech. Based on this approach, Ziegler argues against the examination of volitional or novel nonspeech motor activities to gain insight into motor control for speech. Aims: The primary objective of this paper is to discuss Ziegler's (2003) conceptualisation of the task-dependent model and present an alternative integrative model. In the latter, speech and volitional nonspeech motor control are integrated into the functioning of a more general motor system where neural and behavioural systems demonstrate areas of overlap. Studies of the nervous system, the evolutionary foundations of speech in great apes, behaviour, and motor learning are presented to support an integrative model of motor control. Main Contribution: Neurological and evolutionary evidence strongly suggest that neural networks are flexible, multifaceted, multifunctional, and overlapping in function. It is highly likely that a higher-level behaviour like speech involves networks that are similarly multifunctional and overlapping with other motor functions. Ziegler's concept of taskdependent motor control may relate as much to parameters such as complexity, familiarity, and automaticity of task performance as to the nonspeechÐspeech distinction. Studies are reviewed that support the inclusion of nonspeech motor tasks in assessment of the disordered speech motor control system. Specific nonspeech tasks clearly facilitate differential diagnosis and provide insight into the functioning and breakdown of the motor system for related but more complex speech behaviours. Finally, motor learning studies are discussed with particular reference to how these might inform models of motor control.

The Oxford Handbook of Neurolinguistics

The production of speech is a multistep process requiring close coordination between neurolinguistic, neurocognitive, and neuromotor processes to communicate fluently and seemingly effortlessly. This complex process, which combines speech-specific and domain-general neural mechanisms, involves a closed repertoire of motor programs to control over 100 muscles distributed over the face, neck, and abdomen. The process requires neuromotor mechanisms to implement phonological planning, response selection, sequencing, and timing, contextual adjustments of the motor programs, as well as action execution and response monitoring. Recent advances in neuroimaging and neuromodulation techniques have led to the emergence of neurobiologically realistic models of speech production, leading to more comprehensive understanding of the mechanisms involved in producing speech. This chapter reviews the most up-to-date knowledge on the neural organization of the brain systems involved in producing speech.

Motor control

Action to language via the mirror …, 2006

From Sound to Sensé, 2004

In the present paper we will address two issues. First, are the units of speech static targets or dynamically specified gestures? The available evidence favors the conclusion that dynamic signal attributes play an important role in speech perception, However, the perceptual significance of speech dynamics does not compel us to conclude that the input to the speech production system is dynamic (gestural). Parsimony would seem to dictate that dynamic motor commands be put on hold until physiological and biomechanical response characteristics of the speech production system are better understood. Second, are speech units articulatory or perceptual? This is a question that derives from much quoted programmatic statements by Stetson and Jakobson. Evidence was reviewed showing that speech movements, like nonspeech actions, are adaptively organized and can be planned so as to facilitate the listener's task by enhancing the perceptual correlates of phonetic categories. However, there is also data indicating that these categories have a strong isomorphism with articulatory processes. The implication of this conclusion is that the question of where in the speech chain units are best defined may be a spurious one.

Journal of Phonetics, 2017

Journal of Memory and Language, 1985