The need for self-report data in the assessment of stuttering therapy efficacy: repetitions and prolongations of speech. The stuttering syndrome

Abstract

Background: Bloodstein reviewed hundreds of studies that investigated the efficacy of therapeutic protocols for ameliorating the stuttering syndrome. Surprisingly, almost all were effective in significantly reducing overtly perceptible behaviours such as repetitions and prolongations of speech sounds. These results seem highly improbable considering that many of the treatment methods were diametrically opposed in their principles and implementation procedures (e.g. psychoanalysis, drug therapy, behaviourism, cognitive behavioural therapy and auditory feedback devices with rate control, etc.). In addition, time and more ecologically valid methods such as self-report measures demonstrate that overt measures of success are tenuous, their ameliorative effects tend to diminish drastically over time and show poor generalizability. Further, the real conundrum in stuttering therapy is the failure to acknowledge stuttering as a complete syndrome of continuous compensatory behaviours.

Aims: To highlight how self-report measures serve as a primary tool to understand the syndrome-like nature of stuttering and to test the efficacy of the therapy outside the confines of the clinic and the needs of the people who stutter.

Methods & procedures/outcomes & results: In the past, therapeutic efficacy has typically been measured by the reduction in overtly observable and countable events of stuttering such as repetitions and prolongations. However, recent neuroimaging data and our research suggest that the stuttering syndrome is more than the mere presence of peripheral speech disruptions. Stuttering is a central, experiential sense of 'loss of control' that manifests itself across a continuum of compensatory behaviours from the central nervous system outwards to the speech periphery. In other words, aberrant neural activity, as well as covert stuttering behaviours, subperceptual stuttering forms and overt speech disruptions are all effects or compensations for the central involuntary 'neural block'. Hence, by counting only perceptible portions of the disorder, efficacy measures 'fail to capture' the experiential sense of 'loss of control' and the covert compensatory behaviours of the disorder (i.e. avoidances of words or situations, substitutions, circumlocutions, subperceptual stuttering forms, etc.). Furthermore, unnatural sounding speech, decreased ease of speech production, elevated levels of clinic room fluency and poor reliability in counting stuttering behaviours confound the overt measures in the clinic milieu. Therefore, while overt measures remain important, used in isolation, they cannot provide a 'true metric' of efficacy.

Conclusions: Any efficient and effective means of evaluating intervention methods over the long-term should include a form of self-report as a primary tool as it best accesses the experiential sense of 'loss of control' and other covert behaviours. Overt measures should be used to supplement or complement the self-report data.