Here, you find articles about my theory of stuttering
and about particular aspets of the theory.

Developmental stuttering may be caused by insufficient processing of auditory feedback

Journal of Mediacl Hypotheses, 2023. DOI: 10.1016/j.mehy.2023.111166

Developmental stuttering has been scientifically researched for about a hundred years, but the cause is still unknown. Here, a comprehensive causal hypothesis is presented, from the factors contributing to a predisposition for stuttering to the mechanism underlying the core symptoms: A deficit in attention regulation and/or auditory processing abets a misallocation of attention, i.e., of perceptual and processing capacity, during speech; this results in poor processing of the auditory feedback of speech. Insufficiently processed auditory feedback causes error signals in the speech network which, by an error-induced interaction between cerebellum and basal ganglia, interrupts the speech flow against the speaker’s will. The allocation of attention during speech is hypothesized to be a variable state that forms the interface between the physiological pathomechanism of stuttering, on the one hand, and situational, cognitive, and emotional factors influencing stuttering severity, on the other hand; the interaction between both accounts for the situational variability of the disorder. The hypothesis implicates that increased attention to the auditory feedback of speech (listening to one’s voice) reduces stuttering – this opens, both, a way to test the hypothesis and to improve the therapy.

Overview of conditions that immediately reduce stuttering and a unifying account for their effect.

DOI: 10.20944/preprints202207.0132.v1

It has been known for a long time that many people who stutter are immediately fluent in certain conditions, for instance, when they speak in unison with others, in sync with the clicking of a metronome, or when they hear themselves speak in an altered manner. To under-stand why stuttering is reduced or even eliminated in such conditions is desirable because it may help understand why stuttering occurs in normal speaking conditions. However, empirical findings in this area appear conflicting and confusing, especially with regard to the role of auditory feedback. The article gives an overview of the variety and diversity of fluency-enhancing conditions and of theories proposed to explain their effect. These theories are evaluated in the light of recent empirical findings. A new hypothesis is proposed, based on findings showing that speech processing is limited without attention to the auditory channel. It is assumed that fluency-enhancing conditions draw the speaker’s attention to the auditory channel and, thereby, improve the processing of auditory feedback and its use in speech control. Implications of this account for a causal theory of stuttering and for the treatment of the disorder are discussed.

This paper is a much more extensive treatise of what is delineated in Section 3.1 in this website. The paper contains a section about inner speech (Sec. 10), which is an improved version of the article below, more precisely, of its main part (Sec. 2 and 3).

Why does stuttering disappear when one’s own speech is not heard? External and internal auditory feedback and their impact on stuttering. (2020)
PDF 190 kB

Neurological findings suggest that auditory feedback is used in speech control less effectively by individuals who stutter, as compared with normally fluent speakers; therefore, insufficient auditory-motor integration has been hypothesized to be a causal factor in stuttering. On the other hand, people who stutter are usually fluent when they do not hear themselves speak. This suggests that auditory feedback is irrelevant for speech control and even harmful for individuals who stutter. The present paper proposes an explanation for these seemingly conflicting observations.
It is assumed that speech feedback in the auditory modality is necessary for the control of fluent speech. When no external auditory feedback is available, e.g., because of masking by noise, speech control shifts to an internal feedback loop that provides predictions of the auditory consequences of speech motor commands to the speech comprehension system. In this way, one’s own speech is heard internally. The use of this internal ‘auditory’ feedback saves from stuttering because of a close coupling between speech production and speech perception. However, the internal feedback loop works only if no external auditory feedback is available. Therefore, the internal feedback loop cannot compensate for insufficient integration of external auditory feedback in normal conditions, i.e., when one’s own voice is heard during speech.
Therefore, the hypothesis that insufficient integration of auditory feedback is a causal factor in developmental stuttering is consistent with the fact that stuttering disappears when one’s own speech is not heard. Article length: 12 pages plus references

List of studies concerning auditory processing deficits and stuttering. PDF 152 kB

See also Blog 15


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