The American Journal of Speech-Language Pathology recently published an article titled, “The Importance of Production Frequency in Therapy for Children with Apraxia of Speech (CAS).” The research was conducted by Denice Edeal and Christina Gildersleeve-Neumann from Portland State University. Their research question was to determine whether or not more practice of speech targets would lead to better performance by children with CAS within a speech therapy session and if more practice would lead to better “generalization” (increased performance on words that were not involved in the child’s training).
Because the hallmark feature of CAS is faulty speech motor planning and programming, it is theorized that using variables or principles from the professional literature on other types of motor learning may be advantageous in the treatment for CAS. Clinical practice as well as a growing body of research seems to bear out those ideas. Speech-language pathologists (SLPs) who are successful in treatment for children with apraxia often state that these children, in particular, need more INTENSIVE speech therapy. In this instance, intensive refers to the degree of practice the child receives within the individual speech therapy session. In citing leading researchers on motor learning, the author’s write, “Schmidt and Lee propose amount of practice is a key variable in motor learning. They suggest that the more practice opportunities an individual has, the better the individual’s performance of a motor task will be, which in turn lead to greater learning of these motor tasks.” Overall, more productions of speech targets by the child equals a greater degree of intensity.
In addition to considering the question of intensity of speech practice opportunities, the researchers decided to use an “integral stimulation” therapy method that is consistent with the Schmidt and Lee theories and the principles of motor learning. Dynamic Temporal and Tactile Cueing (DTTC) is a modification of the integral stimulation method used in the treatment of adult apraxia of speech. DTTC has been adapted for use with children, specifically children with a diagnosis of apraxia of speech. Multisensory cueing (visual, verbal, tactile, auditory, etc.) and other strategies such as a slowed rate of production are used within a hierarchical framework in order to target syllables, words or phrases, depending on the child’s current level of functioning. An SLP can move up or down the hierarchy depending on the child’s “real time” level of performance. In Edeal & Gildersleeve-Neuman’s research, they created an experiment in which two children with apraxia each received two conditions of practice in each session. One condition was called “moderate frequency” in which, through the DTTC therapy approach, 30 to 40 speech productions were elicited from the child. The other condition, using the same DTTC method of therapy, was called “high frequency” in which 100 to 150 speech targets were elicited during that segment. In the course of a session, each child received 15 minutes of moderate frequency and 15 minutes of high frequency practice. Different types of speech targets were used in each condition so that the effect of each condition could be evaluated.
Regarding the overall therapy approach, the researchers found that an integral stimulation approach to speech therapy (DTTC), which incorporates principles of motor learning, benefitted both children. One child’s consonant accuracy rose nearly 50 percent in 11 weeks. The other child’s intelligibility rose 11 percent in five weeks.
Regarding the moderate versus high frequency condition of practice, the researchers found that both children benefitted more from the high frequency practice than they did the moderate frequency practice. The speech targets treated in the high frequency condition led to increased in-session accuracy as well as greater generalization to untrained targets. In addition to the improved in-session accuracy and generalization with higher frequency practice, the authors point out that this same practice demonstrated the accuracy could be achieved in fewer sessions. Furthermore, targets that received treatment in the high frequency condition were more stable and accurate from session to session compared to speech targets trained with the moderate frequency condition.
The Bottom Line
The results reported in the Edeal and Gildersleeve-Neumann study are very encouraging yet have limitations. First of all, the number of reported subjects was very small. Secondly, subjects had some variability in the length of their treatment. Issues such as the motivation of the child may also enter into the mix. However, on the positive end, this report confirms other studies in which multi-sensory therapies such as DTTC, which incorporate the principles of motor learning, are effective methods to treat a difficult disorder like CAS. Keep in mind to aim for the following in speech therapy sessions:
- A high degree of direct practice of speech targets. A child should have dozens and dozens of speech productions during each therapy session. A child that is saying or attempting little in a speech therapy session will not likely make progress like a child who is able to have a high degree of practice opportunities.
- Therapy approaches that incorporate principles of motor learning may be key to progress for children with a primary diagnosis of apraxia of speech.
- It is worth mentioning that children with apraxia of speech should work on actual speech during speech therapy. This is consistent with motor learning theory which suggests that to improve performance for a particular task, one should practice that specific task.
Source: Edeal, DM and Gildersleeve-Neumann, CE. The Importance of Production Frequency in Speech Therapy for Childhood Apraxia of Speech. American Journal of Speech-Language Pathology. May 2011, Vol. 20, 95 – 110.