Using electropalatography to treat severe acquired apraxia of speech

Acquired Apraxia of Speech: Comparison of Electropalatography Treatment and Sound Production Treatment

Purpose This investigation compared 2 treatment approaches for acquired apraxia of speech. The effects of a treatment that uses an articulatory-kinematic approach in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) were compared to Sound Production Treatment (SPT), an established behavioral treatment that is also an articulatory-kinematic approach. Method A multiple baseline design across behaviors and participants was used with 2 participants with chronic apraxia of speech and aphasia. Accuracy of target speech sounds in treated and untreated words or phrases in probe sessions served as the dependent variable. The effects of 2 treatments based on an articulatory-kinematic approach were compared: (a) VBFB via EPG and (b) SPT. The order of treatments was counterbalanced across participants. Results Positive changes in articulatory accuracy were observed for SPT and VBFB treatment via EPG. Generalization to untreated stimulus items composed of treated speech sounds was also positive for both treatments. However, participants achieved greater articulatory accuracy with SPT during treatment and better long-term maintenance. Discussion Both treatment approaches resulted in improved speech production accuracy, but gains were greater for SPT. However, further research with additional participants is needed due to the small sample size included in this investigation.

Efficacy of Electropalatography for Treating Misarticulation of /r/

PURPOSE

The purpose of the present study was to document the efficacy of electropalatography (EPG) for the treatment of rhotic errors in school-age children. Despite a growing body of literature using EPG for the treatment of speech sound errors, there is little systematic evidence about the relative efficacy of EPG for rhotic errors.

METHOD

Participants were 5 English-speaking children aged 6;10 to 9;10, who produced /r/ at the word level with < 30% accuracy but otherwise showed typical speech, language, and hearing abilities. Therapy was delivered in twice-weekly 30-min sessions for 8 weeks.

RESULTS

Four out of 5 participants were successful in achieving perceptually and acoustically accurate /r/ productions during within-treatment trials. Two participants demonstrated generalization of /r/ productions to nontreated targets, per blinded listener ratings.

CONCLUSIONS

The present findings support the hypothesis that EPG can improve production accuracy in some children with rhotic errors. However, the utility of EPG is likely to remain variable across individuals. For rhotics, EPG training emphasizes one possible tongue configuration consistent with accurate rhotic production (lateral tongue contact). Although some speakers respond well to this cue, the narrow focus may limit lingual exploration of other acceptable tongue shapes known to facilitate rhotic productions.

Characterizing Articulation in Apraxic Speech Using Real-Time Magnetic Resonance Imaging

Purpose

Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown to capture and quantify salient aspects of apraxic speech, substantiating and expanding upon evidence provided by clinical observation and acoustic and kinematic data. Analysis of apraxic speech errors within a dynamic systems framework is provided and the nature of pathomechanisms of apraxic speech discussed.

Method

One adult male speaker with apraxia of speech was imaged using real-time MRI while producing spontaneous speech, repeated naming tasks, and self-paced repetition of word pairs designed to elicit speech errors. Articulatory data were analyzed, and speech errors were detected using time series reflecting articulatory activity in regions of interest.

Results

Real-time MRI captured two types of apraxic gestural intrusion errors in a word pair repetition task. Gestural intrusion errors in nonrepetitive speech, multiple silent initiation gestures at the onset of speech, and covert (unphonated) articulation of entire monosyllabic words were also captured.

Conclusion

Real-time MRI and accompanying analytical methods capture and quantify many features of apraxic speech that have been previously observed using other modalities while offering high spatial resolution. This patient's apraxia of speech affected the ability to select only the appropriate vocal tract gestures for a target utterance, suppressing others, and to coordinate them in time.

The Use of Electropalatography in the Treatment of Acquired Apraxia of Speech

PURPOSE

This investigation was designed to examine the effects of an articulatory-kinematic treatment in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) on the accuracy of articulation for acquired apraxia of speech (AOS).

METHOD

A multiple-baseline design across participants and behaviors was used with 4 individuals with chronic AOS and aphasia. Accuracy of target speech sounds in treated and untreated phrases in probe sessions served as the dependent variable. Participants received an articulatory-kinematic treatment in combination with VBFB, which was sequentially applied to 3 stimulus sets composed of 2-word phrases with a target speech sound for each set.

RESULTS

Positive changes in articulatory accuracy were observed for participants for the majority of treated speech sounds. Also, there was generalization to untreated phrases for most trained speech sounds. Two participants had better long-term maintenance of treated speech sounds in both trained and untrained stimuli.

CONCLUSIONS

Findings indicate EPG may be a potential treatment tool for AOS. It appears that individuals with AOS can benefit from VBFB via EPG in improving articulatory accuracy. However, further research is needed to determine if VBFB is more advantageous than behavioral treatments that have been proven effective in improving speech production for speakers with AOS.

Effects of EPG treatment for English consonant contrasts on L2 perception and production

Links between perception and production were investigated for two adult native speakers of Korean who participated in electropalatographic (EPG) treatment designed to teach phonological and articulatory contrasts between English /s/ - /ʃ/, /z/ - /ʤ/, and /l/ - /ɹ/. Participants were successful in learning to produce the English contrasts. Perception of English consonants was tested pre- and post-treatment. Post-treatment perception improved somewhat for treated consonants but not for untreated consonants, although perception was not directly trained.

Instrumental and perceptual phonetic analyses: the case for two-tier transcriptions

In this article, we discuss the relationship between instrumental and perceptual phonetic analyses. Using data drawn from typical and atypical speech production, we argue that the use of two-tier transcriptions, which can compare and contrast perceptual and instrumental information, is valuable both for our general understanding of the mechanisms of speech production and perception and also for assessment and intervention for individuals with atypical speech production. The central tenet of our case is that instrumental and perceptual analyses are not in competition to give a single 'correct' account of speech data. They take instead perspectives on complementary phonetic domains, which interlock in the speech chain to encompass production, transmission and perception.

Electropalatography in the description and treatment of speech disorders in five children with cerebral palsy

Some children with cerebral palsy have articulation disorders that are resistant to conventional speech therapy. The aim of this study was to investigate whether the visual feedback method of electropalatography (EPG) could be an effective tool for treating five children (mean age of 9.4 years) with dysarthria and cerebral palsy and to explore whether training improved the posteriorly placed articulation of the Swedish dental/alveolar target consonants /t/, /d/, /n/ and /s/ produced in different positions. An EPG analysis was conducted and some of the data were combined with a perceptual analysis. A more anterior placement was seen after treatment for the target sounds. Features of diagnostic importance revealed were unusual tongue-palate contacts, such as double articulation and abnormally retracted articulation. A possible change in stop closure duration was indicated. The results suggest that EPG could be of potential benefit for diagnosing, treating and describing articulation errors associated with cerebral palsy.

Electropalatography treatment for articulation impairment in children with dysarthria post-traumatic brain injury

PRIMARY OBJECTIVE

Dysarthria with severe articulatory impairment is a common and debilitating sequelae following severe traumatic brain injury (TBI). Eectropalatography (EPG) is an instrumental treatment technique allowing visual feedback of tongue to palate movement during real time articulation. The present study investigated the effectiveness of EPG in treating the articulatory component of dysarthria post-TBI.

STUDY DESIGN/METHODS

The articulatory component of dysarthria post-TBI was treated once per week with EPG over a 10-week period in three adolescents (aged 14 years 10 months-15 years 1 month). A multiple case series ABA treatment design was used. Perceptual (articulation, intelligibility) and EPG (spatial, durational) assessments were conducted pre- and post-treatment to determine outcome.

RESULTS/DISCUSSION

Perceptual improvement was noted for phoneme precision and length. Spatial EPG measures confirmed increased precision of phoneme production. No clear pattern of change for phoneme duration occurred. Intelligibility increased at word and sentence level, with little change reported in everyday speech intelligibility.

CONCLUSION

This preliminary study indicates that EPG treatment may be effective for improving speech at the isolated phoneme, word or sentence level of articulation. These preliminary results are encouraging, being the first study to report speech changes post-treatment in participants with severe TBI and persistent dysarthria. Further research is required, however, in order to understand the regenerative capacity of articulatory function post-brain injury and to determine optimal treatment parameters for achieving generalization of therapy to everyday connected speech.

A re-evaluation of the nature of speech errors in normal and disordered speakers

It is well known that speech errors in normal and aphasic speakers share certain key characteristics. Traditionally, many of these errors are regarded as serial misorderings of abstract phonological segments, which maintain the phonetic well-formedness of the utterance. The current paper brings together the results of several articulatory studies undertaken independently for both subject populations. These show that, in an error, instead of one segment substituting for another, two segments are often produced simultaneously even though only one segment may be heard. Such data pose problems for current models of speech production by suggesting that the commonly assumed dichotomous distinction between phonological and phonetic errors may not be tenable in the current form or may even be altogether redundant.

Response generalization in apraxia of speech treatments: taking another look

The purpose of the present paper is to present a critical review and reanalysis of response generalization effects in studies of treatment efficacy in apraxia of speech (AOS). Response generalization takes two forms: generalization of treatment effects to untrained exemplars of trained behaviors and generalization to untrained (i.e., novel) behaviors. In the past, response generalization has not been extensive and typically has been restricted to untrained exemplars of trained behaviors. Reasons for these findings are discussed with reference to recent advances in our understanding of the nature of AOS and to theories of speech motor control and teaming. The discussion focuses on the influence of the theoretical basis used to develop hypotheses and select behaviors to test predictions, the complexity of the treatment task/s, and patient characteristics. Suggestions for future directions in treatment efficacy research are offered. Learner outcomes: (1) An understanding of the nature of AOS, based on recent experimental analyses. (2) An understanding of the efficacy of current treatments for AOS in the area of response generalization. (3) An understanding of how theories of speech motor control might be applied to develop hypotheses for testing and increase effectiveness in treatment studies. (4) An understanding of how theories of speech motor control might guide selection of behaviors to test treatment effects and response generalization.