History of Problem
In 1999, Katz et al. explored EMA as a means of remediating fricative articulation deficits. They conducted this experiment on a 63-year-old woman with Broca’s aphasia and moderate-to-severe AOS. For 1-month she was provided with: EMA visual feedback for tongue tip position during fricative production and foil treatment in which a computer program delivered voicing-contrast stimuli for simple repetition. There was improvement from the visually guided feedback. The phonetic contrast treated in the foil condition showed only slight improvement, with a return to baseline 10 weeks later. A number of studies have shown that facilitatory effects are not always predictive of post-treatment retention of skills but it’s rather, a number of variables interact to affect motor learning. These variables include: type of feedback, the amount of repetitive practice, the schedule under which the practice trials are performed, and the supporting cognitive mechanisms.
The article cites Van der Merwe, 1997 described Apraxia of speech (AOS) is a speech motor deficit thought to involve motor planning. McNeil, Robin, & Schmidt, 1997 define it as planning / programming impairments. A new treatment method is currently under study. It involves providing augmented feedback of articulatory movements by means of an electromagnetic articulography system (EMA). This is a non-invasive method for tracking speech movements. It uses low-strength magnetic fields. Its aim is to use visual feedback to clarify movement aspects of speech. EMA can be used to treat speech motor deficits in individuals with Broca’s aphasia and AOS.
This study was aimed at answering certain questions, they were: Does EMA supplied feedback improves articulatory accuracy in an adult with acquired AOS? Does feedback frequency results in decreased performance during acquisition? What are the enhanced maintenance and generalization of the targeted behaviors?
Pros & Cons of the Speech Measuring Tools Involved in the Study
They EMA machine used are non-invasive method for tracking speech movements. It uses low-strength magnetic fields that causes minimal or no damage at all.
Research Methodology/Data Analysis:
The participant was a 50-year-old female monolingual speaker of American English. She had sustained a left-hemisphere middle cerebral artery CVA 9 months before treatment. The participant was diagnosed with a moderate Broca’s aphasia. Five repetitions of a probe list containing five words were used for each treated SMT group and between three to eight words1 for the untreated SMTs. 17 to 26 were control SMTs. All these were assigned by a Latin square method. The words used contained a variety of vowels and consonants. The experimental design involved multiple baselines across behaviors. They were both with frequent and infrequent feedback conditions. The baseline performance of a participant was measured during the first four sessions. Treatment was then applied sequentially to the five words representing the selected SMT until the average of treated targets for three consecutive probes reached 80% correct or higher, or a total of 20 training sessions had ended. Long-term maintenance was determined in two sessions conducted one month post-treatment.
Conclusion: Findings/Results of the article
The majority of the untreated words showed increased variability during the training phases for the three treated targets. There was little improvement by 1 month post-treatment, and there were many instances of no change during the course of the experiment. There were sufficient stable baselines to suggest that the gains noted for treated items did not result from across-the-board improvement or unassisted recovery. Contrary to predictions, treatment of /θ/-containing SMTs with 50% feedback corresponded with relatively rapid acquisition and poor overall maintenance, compared to the targets treated with 100% feedback occurred for some items. The main finding of this study is that the augmented kinematic feedback improved production for a majority of treated targets for an individual with AOS. To summarize the findings of this study provide qualified evidence that kinematic feedback improved the speech of this individual with AOS. Systematic replication of this technique on additional individuals with varying factors known to affect motor and verbal learning will determine the conditions under which this technique is efficacious and effective
Katz, W., McNeil, M., & Garst, D. (January 01, 2010). Treating apraxia of speech (AOS) with EMA-supplied visual augmented feedback. Aphasiology, 24, 826-837.