Using Motor Learning Guided Theory and Augmentative and Alternative Communication to Improve Speech Production in Profound Apraxia: A Case Example
Lasker, Joanne P., Stierwalt, Julie A. G., Hageman, Carlin F., LaPointe, Leonard L., Journal of Medical Speech - Language Pathology
A 49-year-old man with profound apraxia of speech and moderate nonfluent aphasia participated in a two-pronged treatment that combined the motor learning guided (MLG) approach for apraxia of speech and augmentative and alternative communication (AAC). When he began the treatment protocol, JW was 4 years postonset from a series of three left cerebrovascular accidents. Researchers implemented a hierarchical motor learning guided approach that manipulated aspects of practice and feedback to help the client acquire and retain targeted words and phrases. In addition, researchers assisted in JW acquiring a speech generating device (SGD) with which he practiced treatment targets at home daily. After three cycles of the combined treatment protocol, JW made gains in acquiring and using treatment targets, as well as in producing untreated stimuli. The combination of treatment approaches--MLG and home practice with an SGD--resulted in changes in speech production in a client with profound apraxia who experienced limited success with more traditional apraxia treatment approaches.
In recent years treatment for apraxia of speech (AOS) has deviated from more traditional approaches, primarily in the methods adopted for eliciting speech practice. The departure from method has occurred as a result of an examination of the motor learning literature. Speech production certainly requires motor learning, starting with a program formulated by the central nervous system that is executed and modified as necessary by the oral motor system. As such, parallels with speech execution can be drawn with other motor systems in the body. Schmidt and colleagues have published extensively in the areas of motor control and learning (Schmidt, 1988; Schmidt & Bjork 1992; Schmidt & Wrisberg, 2000) particularly for motor learning involving the limbs. Other investigators (Ballard, 2001; Hageman, Simon, Backer, & Burda, 2002; Kim, 2007) have expanded on Schmidt's theory to include basic research and application of motor learning principles to the speech motor system.
According to Schmidt's schema theory of motor learning, the primary factor for refining a motor task is practice. During practice people develop recall and recognition schemata to facilitate learning. A recall schema is the capability to produce a desired response, whereas a recognition schema is "used to identify movement errors and evaluate response effectiveness" (Husak & Reeve, 1979, p. 216). Practicing a variety of motor responses that increase the interaction between cognitive processes and motor control further strengthens these schemata. In other words, providing opportunities to practice a motor plan is an important feature of treatment. Additionally, providing that practice in a variety of contexts (which will require constant reactivation of the motor plan) will strengthen motor learning.
The concept of variable practice is counterintuitive based on the requirements of traditional articulation practice. The traditional model calls for starting with a target sound, then practicing and stabilizing that sound in isolation before incorporating it into other contexts. Schmidt's motor learning theory suggests that the act of executing a motor plan in a variety of contexts increases the development of recall and recognition schemata which leads to improved performance and later, improved transfer to novel tasks (Ballard, 2001 Husak & Reeve, 1979; Lee & Magill, 1983; Lee, Magill, & Weeks, 1985; Newell & Shapiro, 1976). Motor learning theory also cautions against the use of extensive clinician provided feedback, another core component to traditional approaches. In the traditional approach, extensive external feed-back is provided by the clinician in the form of accuracy (how close the production is to the target) and performance (what you should do to modify the production). …