Principles of Motor Learning – Motor Based Treatment Approach: Motor learning is a fascinating part of human behavior that involves the acquisition of skills through practice and experience. Whether it’s learning to ride a bike, play a musical instrument, or master a sport, motor learning principles are crucial in developing our talents. In this post, we will look at the fundamental principles of motor learning and how they affect skill acquisition and performance. Motor learning principles are particularly relevant to AOS treatment, and they are included in nearly all specific approaches to treating the illness that have some evidence of benefit. The following sections examine the principles that appear to be most applicable to AOS.
Principles of Motor Learning for Motor Based Treatment Approach
- Instruction and Self-Learning
- Specificity of Training
- Consistent and Variable Practice
- Speed-Accuracy Trade-Offs
Every individual behavioral treatment technique for AOS or Other Speech Sound Disorders emphasizes drill. The necessity for extensive and systematic training is compatible with motor learning principles and the idea that, for some individuals, their issue represents more than inefficiencies in speech planning or programming. More than a small percentage of apraxic speakers appear to have “lost” part of the preprogrammed subroutines for movement sequences that make regular speech so smooth. Thus, Wertz, LaPointe, and Rosenbek defined AOS treatment as “the structured relearning of skilled speech movements,” and Rosenbek et al claimed that systematic intensive and extended drill is required to regain or acquire lost speech abilities.
Drilling becomes systematic when target responses are based on the deliberate selection and sequencing of stimuli that encourage success at each stage of the treatment program. Drilling is rigorous and extensive when as many reactions as feasible occur during each of the frequent treatment sessions.
Instruction and Self-Learning
Patients should be encouraged to evaluate their speech, look for correct targets, and self-correct as early as possible. Many apraxic speakers can learn on their own, especially if their impairment is not severe, and what they learn on their own may not be improved upon by clinician training. Clinicians can often assist patients by discovering productive self-cueing strategies and then assisting them in using them consciously in various circumstances.
Apraxic speakers, particularly those whose treatment must begin at the sound, syllable, or word level, may require assistance in learning how to generate speech motions. This can take the form of basic watch and listen imitation exercises in which the clinician demonstrates what has to be done. More explicit education is required at times. Phonetic placement and phonetic derivation techniques, as well as instructions and cues for adjusting pace and emphasis, are frequently required for teaching sound generation. Furthermore, instruction is a required component of several of the highly structured therapy programs outlined later. In all cases, instruction should be muted as soon as learning has happened.
All Speech therapies include some type of feedback. Many patients can appraise the accuracy of their responses reliably and accurately, and they should be encouraged to do so from the start, including efforts at self-correction when they judge responses to be unsatisfactory. Clinician feedback is both reinforcing and encouraging; it may be especially helpful when working on nonspeech tasks, noncategorical speech tasks (e.g., tasks stressing stress or rate), or when intelligibility is the immediate goal.
Instrumental biofeedback and other forms of feedback may also be beneficial. The use of a mirror can help some patients acquire a strong visual image of correct actions or targets, but some individuals do not benefit or are confused by such feedback. The use of electromyography (EMG), electromagnetic articulography (EMA), electropalatography (EPG), biofeedback, and vibrotactile stimulation for particular patients is explored under the section on specialized behavioral therapy techniques.
Specificity of Training
When a patient has some success with words or phrases, it is rarely suitable to focus on nonspeech actions or sound generation in isolation. The syllable is a core unit of speech programming in children and mature speakers, and there is minimal evidence to support the assumption that concentrating on sounds in isolation will extend to syllables and words. Other evidence suggests that nonspeech oromotor skills do not always transfer to speech tasks. Furthermore, words and phrases are motivational, relevant, and specific to the final goal of treatment.
For mute apraxic patients, vegetative or reflex behaviors such as grunting, coughing, and laughing may need to be reflexively evoked and then bent toward volitional control as a precursor to voluntary or automatic speech production. The goal of such nonspeech exercises is not to improve strength or other parameters of physiologic support for speaking, but rather to improve the planning or programming of volitional oral movements.
Consistent and Variable Practice
Many therapy methods include consistent (blocked) practice. In treatment, for example, investigators frequently use many trials of multiple repetitions of sounds, words, phrases, nonsense syllables, or nonspeech oromotor motions, sometimes without intermediate stimuli. These constrained practice efforts frequently give way to variable (random) practice in which various sounds are targeted or the patient is forced to program more elements into replies, with syllable-to-syllable or response-to-response variability. Thus, syllable repetition may merge into phonetic contrast tasks in which diversity of answers must be produced, either with minimal (e.g., sue-zoo), intermediate (sue-moo), or bigger contrasts (e.g., tomato-tornado).
Contrastive stress tasks, in which stereotypic stress patterns in sentences of identical length and structure (“John likes Mary,” “Mary likes John”) give way to tasks with variable stress placement in phrases of varying length and structure (“John likes Mary,” “Mary likes to sing in church”).
Some research suggests that varied practice, in which various targeted sounds or syllables are offered at random, can promote response acquisition and retention more successfully than blocked practice. This is consistent with the basic premise that random practice is more effective than blocked practice at facilitating motor skill retention and transfer. Although blocked practice may be required in the early phases of treatment for individuals with severe AOS, this concept and these data suggest that varied practice should be employed as soon as progress can be seen in response to it. Some procedures start with blocked practice and progress to random practice once basic goal responses are regularly obtained.
Reduced rate is frequently stressed early in treatment, giving way to attempts to increase speed as accuracy improves. Rate reductions can take numerous types. Patients who are severely handicapped may need to be silent before responding in order to have their response “in mind.” For all but the most automatic utterances, a slow, intentional pattern of speaking may be required to attain correctness. This could be a syllable-by-syllable method to production or a purposeful extension of vocalic nuclei.
The value of rate decrease may come from a different source for apraxic speakers than for dysarthric speakers. Normal speakers’ rate and movement velocity profiles, for example, indicate that changes in rate are connected with changes in motor control methods. A high rate appears to involve “unitary” motions that are primarily preprogrammed, whereas slow rates tend to be composed of many submovements that are impacted by feedback systems. For many apraxic speakers who appear to have lost or lost access to preprogrammed subroutines, rate decrease may assist feedback and “relearning” of the submovements required for proper speech.
Once proper articulation has been obtained throughout treatment, a greater rate should be pursued. This can be done in alternating motion rate (AMR) tests at the syllable, word, or phrase level, in contrastive stress tasks at the phrase level, in sentence and paragraph reading tasks, and so on. For example, how well can a patient sustain a normal phrase rate when asked to recall a picture, letter, or color shown before or during production? Such exercises may also serve as a final step in treatment before progressing to a higher level of response complexity.
- Motor Speech Disorders: Substrates, Differential Diagnosis and Management – Joseph R. Duffy (Book)
- Motor Speech Disorders: Diagnosis and Treatment – Donald B. Freed (Book)