Verbal Response Inhibition in Adults Who Stutter

Abstract

Purpose Adults who stutter (AWS) often attempt, with varying degrees of success, to suppress their stuttered speech. The ability to effectively suppress motoric behavior after initiation relies on executive functions such as nonselective inhibition. Although previous studies found that AWS were slower to inhibit manual, button-press response than adults who do not stutter (AWNS), research has yet to confirm a consistent relationship between manual and verbal inhibition. No study has examined verbal inhibition ability in AWS. The purpose of this study, therefore, is to compare verbal response inhibition between AWS and AWNS, and compare verbal response inhibition to both the overt stuttering and the lived experience of stuttering. Method Thirty-four adults (17 AWNS, 17 AWS) completed one manual and three verbal stop-signal tasks. AWS were assessed for stuttering severity (Stuttering Severity Instrument–Fourth Edition: SSI-4) and experience with stuttering (Overall Assessment of the Speaker's Experience With Stuttering [OASES]). Results Results indicate no correlation between manual and verbal inhibition for either group. Generalized linear mixed-model analyses suggested no significant group differences in manual or verbal inhibition. Manual and verbal inhibition did not predict SSI-4 in AWS. However, verbal inhibition was uniquely associated with OASES scores. Conclusion Although underlying manual and verbal inhibition was comparable between AWS and AWNS, verbal inhibition may be linked to the adverse experience of stuttering rather than the overt symptoms of stuttering severity. Supplemental Material https://doi.org/10.23641/asha.15145185

Dimensions of Temperament in Adults With Chronic Stuttering in the Light of I. P. Pavlov’s Theories

“…He also found that stuttering adults do not differ in terms of BIS/BAS from the control group. In turn, in Treleaven's and Coalson's study people who stuttered much slower inhibited inaccurate motor responses, but not verbal responses (Treleaven & Coalson, 2021).…”

Inhibitory Control, Cognitive Flexibility, and the Production of Disfluencies in Children Who Do and Do Not Stutter

“…Simultaneously, experimental paradigm studies investigating motor or verbal response inhibition in children and AWS have produced mixed findings. Some researchers have reported that participants who stutter do not perform as well as controls, while others have reported comparable performances between the groups (Bakhtiar & Eggers, 2023;Eggers et al, 2018;Harrewijn et al, 2017;Piispala et al, 2016;Treleaven & Coalson, 2021).…”

Why Stuttering Occurs

“…Consistent with the account presented here, other researchers have associated this right hemisphere activation during stuttering with activation of the IFG-STN hyperdirect pathway (Arenas, 2017; Neef et al, 2018). Adults who stutter are not impaired in their ability to inhibit verbal responses (Treleaven & Coalson, 2021), but may exhibit widespread hyperactivity across neural correlates of inhibitory control (Wiltshire et al, 2020). This hyperactivity of inhibitory control in adults who stutter may explain previous findings of faster response times compared to those of fluent controls during cognitive conflict (Subramanian & Yairi, 2006).…”

“…Neural connectivity of the right hemisphere inhibitory network underlying hyperdirect pathway activation increases with stuttering severity (Neef et al, 2018). Faster verbal response inhibition in adults who stutter is also associated with greater physical concomitants of stuttering (Treleaven & Coalson, 2021). Stuttering severity may be related to the speed in which the hyperdirect pathway freezes the speech motor system in the face of cognitive conflict.…”