Autonomic nervous system activity of preschool-age children who stutter

The purpose of this study was to investigate potential differences in autonomic nervous system (ANS) activity to emotional stimuli between preschool-age children who do (CWS) and do not stutter (CWNS).

Participants were 20 preschool-age CWS (15 male) and 21 preschool-age CWNS (11 male). Participants were exposed to two emotion-inducing video clips (negative and positive) with neutral clips used to establish pre-and post-arousal baselines, and followed by age-appropriate speaking tasks. Respiratory sinus arrhythmia (RSA)-often used as an index of parasympathetic activity-and skin conductance level (SCL)-often used as an index of sympathetic activity-were measured while participants listened to/watched the audio-video clip presentation and performed a speaking task.

CWS, compared to CWNS, displayed lower amplitude RSA at baseline and higher SCL during a speaking task following the positive, compared to the negative, condition. During speaking, only CWS had a significant positive relation between RSA and SCL.

Present findings suggest that preschool-age CWS, when compared to their normally fluent peers, have a physiological state that is characterized by a greater vulnerability to emotional reactivity (i.e., lower RSA indexing less parasympathetic tone) and a greater mobilization of resources in support of emotional reactivity (i.e., higher SCL indexing more sympathetic activity) during positive conditions. Thus, while reducing stuttering to a pure physiological process is unwarranted, the present findings suggest that the autonomic nervous system is involved.

The reader will be able to: (a) summarize current empirical evidence on the role of emotion in childhood stuttering; (b) describe physiological indexes of sympathetic and parasympathetic activity; (c) summarize how preschool-age children who stutter differ from preschool-age children who do not stutter in autonomic activity; (d) discuss possible implications of current findings in relation to the development of childhood stuttering.