Direction of attentional focus in biofeedback treatment for /r/ misarticulation

Abstract

Structured Abstract Background Maintaining an external direction of focus during practice is reported to facilitate acquisition of nonspeech motor skills, but it is not known whether these findings also apply to treatment for speech errors. This question has particular relevance for treatment incorporating visual biofeedback, where clinician cueing can direct the learner’s attention either internally (i.e., to the movements of the articulators) or externally (i.e., to the visual biofeedback display). Aims This study addressed two objectives. First, it aimed to use single-subject experimental methods collect additional evidence regarding the efficacy of visual-acoustic biofeedback treatment for children with /r/ misarticulation. Second, the study compared the efficacy of this biofeedback intervention under two cueing conditions. In the external focus (EF) condition, participants’ attention was directed exclusively to the external biofeedback display. In the internal focus (IF) condition, participants viewed a biofeedback display, but they also received articulatory cues encouraging an internal direction of attentional focus. Methods & Procedures Nine school-aged children were pseudorandomly assigned to receive either internal or external focus cues during eight weeks of visual-acoustic biofeedback intervention. Accuracy in /r/ production at the word level was probed in three to five pre-treatment baseline sessions and three post-treatment maintenance sessions. Outcomes were assessed using visual inspection and calculation of effect sizes for individual treatment trajectories. In addition, a mixed logistic model was used to examine across-subjects effects including phase (pre/post-treatment), /r/ variant (treated/untreated), and focus cue condition (internal/external). Outcomes & Results Six out of nine participants showed sustained improvement on at least one treated /r/ variant; these six participants were evenly divided across EF and IF treatment groups. Regression results indicated that /r/ productions were significantly more likely to be rated accurate post-treatment than pre-treatment. Internal versus external direction of focus cues was not a significant predictor of accuracy, nor did it interact significantly with other predictors. Conclusions The present results are consistent with previous literature reporting that visual-acoustic biofeedback can produce measurable treatment gains in children who have not responded to previous intervention. These findings are also in keeping with previous research suggesting that biofeedback may be sufficient to establish an external attentional focus, independent of verbal cues provided. The finding that explicit articulator placement cues were not necessary for progress in treatment has implications for intervention practices for speech sound disorders in children.

Retroflex Versus Bunched in Treatment for Rhotic Misarticulation: Evidence From Ultrasound Biofeedback Intervention

“…It is not possible to treat Study 1 and Study 2 as a controlled comparison of ultrasound treatment with and without the option to select individualized tongue shapes, because the two studies differed along other parameters. In particular, participants’ average age was greater in Study 2 than in Study 1, and older participants may be better able to benefit from biofeedback intervention than younger individuals (McAllister Byun, Maas, & Swartz, 2013). Second, although the same clinician was immediately responsible for most treatment delivery in both Studies 1 and 2, the researcher who supervised the intervention and guided clinical decisions differed across the studies.…”

Differential Effects of Visual-Acoustic Biofeedback Intervention for Residual Speech Errors

“…A common approach provides a real-time image of the articulators using technologies such as electromagnetic articulography (e.g., Katz et al, 2010), ultrasound (e.g., Adler-Bock et al, 2007; Preston et al, 2013, 2014, 2016; McAllister Byun et al, 2014b), or electropalatography (e.g., Gibbon et al, 1999). An alternative approach is visual-acoustic biofeedback, in which learners view a dynamic representation of the formants or resonant frequencies of the vocal tract (Shuster et al, 1992, 1995; McAllister Byun and Hitchcock, 2012; McAllister Byun et al, 2016b). …”

Masked Visual Analysis: Minimizing Type I Error in Visually Guided Single-Case Design for Communication Disorders

“…Second, the majority of children in our studies have no speech errors other than /r/ (although a handful do additionally present with dentalization or lateralization of /s /), which rules out a multiple-baseline across-behaviors design. If we treat /r/ in different positions or phonetic contexts (e.g., /ɝ/ versus /ɪɚ/) as different target behaviors, there is a high risk that progress in a treated context will generalize to the untreated context, compromising experimental control (e.g., McAllister Byun, Swartz, Halpin, Szeredi, & Maas, 2016). We are left with the multiple-baseline across-subjects design as our only major means of establishing experimental control.…”

“…2 One arm evaluated the effects of visual-acoustic biofeedback intervention (see McAllister Byun & Hitchcock, 2012;McAllister Byun et al, 2016); another tested ultrasound biofeedback (e.g., McAllister Byun, Hitchcock, & Swartz, 2014;Preston et al, 2013;Preston et al, 2014); and a final arm examined electropalatographic (EPG) biofeedback (e.g., Fletcher, Dagenais, & Critz-Crosby, 1991;Hitchcock et al, in press). Four participants with residual /r/ misarticulation were enrolled in each leg of the study.…”