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.

Resting autonomic activity in adults who stutter and its association with self-reports of social anxiety

PURPOSE

The purpose of this study was to investigate resting autonomic activity in adults who stutter (AWS) compared to adults who do not stutter (ANS) and the relationship this has on self-reports of social anxiety.

METHODS

Thirteen AWS and 15 ANS completed the Social Interaction Anxiety Scale (SIAS; Mattick & Clark, 1998) and Brief Fear of Negative Evaluation (BFNE; Leary, 1983). Following this, measures of skin conductance levels (i.e. index of sympathetic activity) and respiratory sinus arrhythmia (i.e. index of parasympathetic activity) were taken during a 5-minute resting, baseline period. Independent sample t tests were used to assess differences between groups on self-reports of anxiety (SIAS, BFNE) and resting autonomic levels (SCL, RSA). Separate multiple regression analyses were performed in order to assess the relationship between self-reports of anxiety and autonomic measures.

RESULTS

Results showed significantly higher mean SCL and lower mean RSA levels in the AWS compared to the ANS at resting, baseline. Regression analysis showed that self-reports from the SIAS had a significant effect on RSA levels for the AWS but not the ANS. No significant effects were found for BFNE on RSA. Nor was there a significant effect from SIAS or BFNE on SCL levels for either group.

CONCLUSION

Findings suggest that resting RSA levels may be a physiological marker for social anxiety levels in adults who stutter.

The impact of self-reported levels of anxiety on respiratory sinus arrhythmia levels in adults who stutter

PURPOSE

This study investigated whether subjective levels of anxiety predict respiratory sinus arrythmia (RSA) levels in adults who stutter (AWS) compared to (ANS) during baseline and social stress situations.

METHODS

Participants were eight AWS and 10 ANS who performed a modified version of the Trier Social Stress Test (TSST-M). For this, participants were required to prepare and deliver a 5-minute speech and perform a nonword reading task in front of what was perceived as a group of professionals trained in public speaking. Measures of respiratory sinus arrhythmia (RSA) were calculated for baseline and TSST-M conditions. Participants also completed the State-Trait Anxiety Inventory (STAI), both the trait (STAI-T) and state (STAI-S) portion, which served as subjective anxiety ratings. Univariate analyses of variances (UNIANOVA) were used to assess the effects of the STAI-T and STAI-S anxiety on respiratory sinus arrhythmia (RSA) levels at pre-stress and TSST-M conditions. RSA, an index of parasympathetic nervous system activity, is considered to be a measure of emotional regulation. The strength of the effects of STAI-T and STAI-S on RSA levels was evaluated with the unstandardized coefficients for each group separately.

RESULTS

Results showed a significant difference between groups for the effects of STAI-T on RSA values for the pre-stress nonword reading task. No other significant differences were found between groups for the pre-stress or TSST-M conditions. Slope estimates showed that STAI-T was a significant predictor of RSA values for pre-stress speaking conditions for the AWS but not ANS. No significant fixed effects or interaction effects were found for the STAI-S and RSA levels in the AWS or ANS. Nor were there significant effects of STAI-T on RSA levels in the AWS or ANS for TSST-M conditions. Descriptive analysis revealed the effects found in the AWS during pre-stress conditions were attributed to a subgroup of AWS who reported low self-reports of anxiety (i.e. STAI-T) and high levels of emotional regulation (i.e. RSA) across social stress conditions.

DISCUSSION

Low self-reported STAI-T scores simultaneous with high RSA levels in some AWS may reflect a self-regulatory strategy adapted in response to chronic, daily stress associated with stuttering.

Effects of Social Stress on Autonomic, Behavioral, and Acoustic Parameters in Adults Who Stutter

Purpose The purpose of this study was to assess changes in autonomic, behavioral, and acoustic measures in response to social stress in adults who stutter (AWS) compared to adults who do not stutter (ANS). Method Participants completed the State-Trait Anxiety Inventory ( Speilberger, Gorsuch, Luschene, Vagg, & Jacobs, 1983 ). In order to provoke social stress, participants were required to complete a modified version of the Trier Social Stress Test (TSST-M, Kirschbaum, Pirke, & Hellhammer, 1993 ), which included completing a nonword reading task and then preparing and delivering a speech to what was perceived as a group of professionals trained in public speaking. Autonomic nervous system changes were assessed by measuring skin conductance levels, heart rate, and respiratory sinus arrhythmia (RSA). Behavioral changes during speech production were measured in errors, percentage of syllable stuttered, percentage of other disfluencies, and speaking rate. Acoustic changes were measured using 2nd formant frequency fluctuations. In order to make comparisons of speech with and without social-cognitive stress, measurements were collected while participants completed a speaking task before and during TSST-M conditions. Results AWS showed significantly higher levels of self-reported state and trait anxiety compared to ANS. Autonomic nervous system changes revealed similar skin conductance level and heart rate across pre-TSST-M and TSST-M conditions; however, RSA levels were significantly higher in AWS compared to ANS across conditions. There were no differences found between groups for speaking rate, fundamental frequency, and percentage of other disfluencies when speaking with or without social stress. However, acoustic analysis revealed higher levels of 2nd formant frequency fluctuations in the AWS compared to the controls under pre-TSST-M conditions, followed by a decline to a level that resembled controls when speaking under the TSST-M condition. Discussion Results suggest that AWS, compared to ANS, engage higher levels of parasympathetic control (i.e., RSA) during speaking, regardless of stress level. Higher levels of self-reported state and trait anxiety support this view point and suggest that anxiety may have an indirect role on articulatory variability in AWS.

Speech sequence skill learning in adults who stutter

The present study compared the ability of 12 people who stutter (PWS) and 12 people who do not stutter (PNS) to consolidate a novel sequential speech task. Participants practiced 100 repetitions of a single, monosyllabic, nonsense word sequence during an initial practice session and returned 24-h later to perform an additional 50 repetitions. Results showed significantly slower sequence durations in the PWS compared to PNS following extensive practice and consolidation. However, the hypothesis that poor performance gains in PWS compared to PNS during practice would be maintained following a 24-h consolidation period was not supported. Further descriptive analysis revealed large within group differences in PWS which to some extent were attributed to a subgroup of PWS who failed to show any improvements in performance following practice or consolidation. The results and the possible presence of subgroups of PWS are discussed with regard to their limitations in motor learning abilities.

EDUCATIONAL OBJECTIVES

The reader will be able to (1) explain the difference between practice and learning, (2) define consolidation and explain the importance of measuring performance following a consolidation period, (3) understand past research on PWS' performance during both speech and nonspeech motor tasks, and (4) explain why individual differences in practice effects and learning may have important implications for client variability in treatment outcome.