ACQ Vol 12 no 1 2010

Motor speech disorders

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of the movement). KP is information about the nature or quality of the movement. It includes biofeedback and external feedback provided by an instructor (clinician). The article draws on extensive literature regarding the nature of feedback frequency, intensity, and timing. Having disected this complex theory, the article finally draws together the above concepts and discusses the clinical implications when applying it to the people we treat on a daily basis. It provides a case example and shows how intervention may be constructed to improve motor speech outcomes for people with AOS. While I believe there is still much to learn about the motor speech system and how to help repair it once it is broken, this article goes a long way to bridge the divide between principles of learning, practice, feedback, and attention with motor speech production. Included below is the “shortlist” of key articles that form a comprehensive reading list to help unlock the mysteries behind AOS. I hope you enjoy! References Ballard, K.J., Maas, E., & Robin, D. A. (2007) Treating control of voicing in apraxia of speech with variable practice. Aphasiology , 21 (12),1195-1217. Guadagnoli M.A. & Lee, T.D. (2004). Challenge point: A framework for conceptualizing the effects of various practice conditions in motor learning. Journal of Motor Behavior , 36 (2), 212–224. Guenther, F. H. (2006). Cortical interactions underlying the production of speech sounds. Journal of Communication Disorders , 39 , 350–365. Schmidt, R. A. (1975). A schema theory of discrete motor skill learning. Psychological Review , 82 , 225–260. Schmidt, R.A. & Lee, T.D. (1999). Motor control and learning: A behavioural emphasis . (3rd ed.). Champaigne, IL: Human Kinetics. Wambaugh, J.L., Duffy J.R., McNeil, M. R., Robin, D. A., & Rogers, M. A. (2006). Treatment guidelines for acquired apraxia of speech: A synthesis and evaluation of the evidence. Journal of Medical Speech-Language Pathology , 14 (2), xv–xxxiii. Neel, A. (2009). Effects of loud and amplified speech on sentence and word intelligibility in Parkinson disease. Journal of Speech, Language and Hearing Research , 52 , 1021– 1033. Kylie Mulcahy In management of hypokinetic dysarthria related to Parkinson’s disease, the effects of increased vocal effort (or loud speech) as opposed to simple amplification are unclear. In this study, the authors aim to explain the mechanisms that contribute to deficits in speech intelligibility by dichotomising Investigating word intelligibility in Parkinson’s disease

Principles of motor learning Maas E., Robin, D., Austermann Hula, S.N., Freedman, S. E., Wulf, G., Ballard, K. J., & Schmidt, R. A. (2008). Principles of motor learning in treatment of motor speech disorders. American Journal of Speech-Language Pathology , 17 , 277–298. At last! An article that incorporates all you need to know about treating apraxia of speech (AOS). This tutorial-based article incorporates a critical review of existing AOS literature and presents a theoretical framework to better guide clinical management of the disorder. The authors describe the founding principles of general motor learning and go on to apply these principles to speech motor learning. Essential to the development of the links between speech and general motor learning is the concept of “learning versus performance”, which the authors believe to be intimately associated with the holy grail of all speech intervention, namely “improved generalisation and carryover”. The authors draw heavily on the “Schema Theory” (Schmidt, 1975, 2003; Schmidt & Lee, 2005) which assumes that in the intact motor learning system, motor programs are retrieved from memory and subsequently adapted to a specific situation. The motor programs are shaped and honed with increased practice and eventually stored as learned chunks of behaviour. The authors postulate that the principles of motor learning (Schema Theory) extend to impaired speech systems, and demonstrate that with optimal conditions of practice, improved generalisation and carryover can be achieved. Additionally, the authors present a synopsis of the “Challenge point framework” by Guadagnoli and Lee (2004) which augments the theoretical underpinnings of the Schema Theory and introduces the concept of optimal (motor) learning environments to treatment of AOS. In order to assimilate a large amount of theory, the authors discuss key issues, including the structure of practice, attentional focus, movement complexity, and feedback type. The structure of practice is partitioned into: 1) amount, which refers to the overall time spent practising the movements; 2) distribution, which is how the practice is aportioned over time; 3) variability, which describes practice performed in different variations; and 4) schedule, which refers to different movements being used to achieve an unpredictable target. Attentional focus relates to either the internal focus, which is concentrating on kinetic, kinematic, and somatosensory information; or the external focus which describes attention to movement of an object (e.g., golf club) to achieve a goal. Movement complexity relates directly to the Challenge point framework and breaks tasks into simple (part) or whole (complex) movements. Feedback type is divided into knowledge of results (KR) and knowledge of performance (KP). KR is information about the movement outcome, in relation to the goal (provided at the completion Erin Godecke

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ACQ Volume 12, Number 1 2010

ACQ uiring knowledge in speech, language and hearing