The inhibition of stuttering via the perceptions and production of syllable repetitions.

In contrast to most therapeutic protocols for stuttering that induce fluency while producing speech targets, we investigated the possibility of inducing "carry-over" fluency prior to normal speech production. Ten adults who stutter read 7-12 syllable phrases after actively producing (via shadowing) or passively listening to: (a) repeating syllables, matched to the initial syllable of the target utterance; (b) repeating syllables, not matched to the initial syllable of the target; (c) nonrepeating syllables; and (d) fricative /noise-like acoustic signals. Relative to baseline, all active syllabic conditions produced approximately 70% inhibition (reduction) of stuttering in the ensuing target utterances, which is attributed to carry-over from fluent shadowing. The most robust passive inhibition (56%) resulted from listening to matched repeating syllables. These findings further sustain that a perception-production link in speech, possibly resulting from mirror neuron activity, can facilitate the inhibition of stuttering. However, in this study we further demonstrate gestural and temporal flexibility of this mechanism, showing that this inhibitory strategy may be enacted prior to producing speech targets. We discuss possible clinical implications and draw comparisons between core stuttering behaviors (i.e., repetitions and prolongations) and behavioral therapeutic strategies (e.g., slowed speech, preparatory sets) used to inhibit or eliminate stuttering.