Differences in implicit motor learning between adults who do and do not stutter

Erasmus clinical model of the onset and development of stuttering 2.0

A clinical, evidence-based model to inform clients and their parents about the nature of stuttering is indispensable for the field. In this paper, we propose the Erasmus Clinical Model of Stuttering 2.0 for children who stutter and their parents, and adult clients. It provides an up-to-date, clinical model summary of current insights into the genetic, neurological, motoric, linguistic, sensory, temperamental, psychological and social factors (be it causal, eliciting, or maintaining) related to stuttering. First a review is presented of current insights in these factors, and of six scientific theories or models that have inspired the development of our current clinical model. Following this, we will propose the model, which has proven to be useful in clinical practice. The proposed Erasmus Clinical Model of Stuttering visualizes the onset and course of stuttering, and includes scales for stuttering severity and impact, to be completed by the (parent of) the person who stutters. The pathway of the model towards stuttering onset is based on predisposing and mediating factors. In most children with an onset of stuttering, stuttering is transient, but if stuttering continues, its severity and impact vary widely. The model includes the circle of Engel (1977), which visualizes unique interactions of relevant biological, psychological, and social factors that determine the speaker's experience of stuttering severity and its impact. Discussing these factors and their interaction with an individual client can feed into therapeutic targets. The model is supplemented by a lifeline casus.

Morphological deficits of glial cells in a transgenic mouse model for developmental stuttering

Vocal production involves intricate neural coordination across various brain regions. Stuttering, a common speech disorder, has genetic underpinnings, including mutations in lysosomal-targeting pathway genes. Using a Gnptab-mutant mouse model linked to stuttering, we examined neuron and glial cell morphology in vocal production circuits. Our findings revealed altered astrocyte and microglia processes in these circuits in Gnptab-mutant mice, while control regions remained unaffected. Our results shed light on the potential role of glial cells in stuttering pathophysiology and highlight their relevance in modulating vocal production behaviors.

Statistical Information Affects Spoken Word Recognition of Tone Languages in Stutterers: Evidence From an Auditory-Perceptual Gating Study

PURPOSE

Previous studies have shown that individuals who stutter exhibit abnormal speech perception in addition to disfluent production as compared with their nonstuttering peers. This study investigated whether adult Chinese-speaking stutterers are still able to use knowledge of statistical regularities embedded in their native language to recognize spoken words and, if so, how much acoustic information is needed to trigger this information.

METHOD

Seventeen stutterers and 20 typical, nonstuttering controls participated in a gating experiment. All participants listened to monosyllabic words that consisted of syllables and lexical tones and were segmented into eight successive gates. These words differed in syllable token frequency and syllable-tone co-occurrence probability in line with a Chinese spoken word corpus. The correct syllable-only, correct tone-only, correct syllable-tone word, and correct syllable-incorrect tone responses were analyzed between the two groups using mixed-effects models.

RESULTS

Stutterers were less accurate overall than controls, with fewer correct syllables, tones, and their combination as words. However, stutterers showed consistent and reliable perceptual patterns triggered by statistical information of speech, as reflected by more accurate responses to high-frequency syllables, high-probability tones, and tone errors all in manners similar to those of nonstuttering controls.

CONCLUSIONS

Stutterers' atypical speech perception is not due to a lack of statistical learning. Stutterers were able to perceive spoken words with phonological tones based on statistical regularities embedded in their native speech. This finding echoes previous production studies of stuttering and lends some support for a link between perception and production. Implications of pathological, diagnostic, and therapeutic conditions of stuttering are discussed.