The effects of attentional focus on speech motor control in adults who stutter with and without social evaluative threat

Purpose: We sought to investigate the effects of cued attentional shifts on speechmotor control in adults who stutter (AWS) and adults who do not stutter (ANS) when speaking under low and high social stress conditions.

Method: Thirteen AWS' and 10 ANS' lip aperture (LA) and posterior tongue (PT) movements were assessed under a Cued-Internal and Cued-External attentional focus condition with and without social stress induction (i.e. speaking to an audience). Skin conductance levels were used to measure a stress response. Speech motor control was assessed by measuring movement duration and variability of movement for LA and PT using the spatial temporal index (STI).

Results: A significant Group x Condition interaction was found for LA STI. Post-hoc comparisons indicated AWS' LA STI significantly decreased under Cued External Focus conditions during both low and high social stress. No significant Group x Condition interaction was found for PT STI. AWS showed significantly slower tongue movements (PT) across all low and high social stress conditions; however, there was no significant Group x Condition interaction for PT or LA.

Discussion: Findings yield preliminary insights into the role of attentional focus on speech motor control when speaking during high social stress. Theoretical and clinical implications are discussed.