Electrocortical Reactivity and Regulation in 5- To 8-Year Old Children Who Do and Do Not Stutter: An ERP Study of Affective Face Processing

Childhood stuttering is a neurodevelopmental disorder whose etiology is associated with speech motor, linguistic, and emotional factors. Previous research has identified differences in emotional reactivity and regulation between children who stutter (CWS) and typically developing children (TDC). This study sought to determine if event-related brain potentials (ERPs) of 5- to 8-year-old TDC (N = 40) are sensitive to the processing of affective child facial expressions (Experiment 1), and if so, if these ERP correlates for emotional processing differ between matched groups of CWS (n = 16) and TDC (n = 16) (Experiment 2). Images of threatening (angry/fearful) and neutral child facial expressions, preceded by an audio contextual cue, were presented in a passive paradigm without requiring speech production. Audio cues differed in neutral, negative, or reappraisal context. Three conditions differed in audio-image pairing: neutral context-neutral expression (neutral condition), negative context-threatening expression (threat condition), and reappraisal context-threatening expression (reappraisal condition). In both experiments, emotional reactivity was increased by the presentation of threatening versus neutral facial expressions. Conversely, this reactivity was down regulated by cognitive reappraisal. Possible associations between ERP reactivity/regulation effects, dimensions of temperament (CBQ), stuttering severity, and communication attitude (KiddyCAT and CAT) were also investigated. In Experiment 1, LPP elicitation was increased across conditions in the right hemisphere compared to the left hemisphere, a lateralization repeatedly observed in previous literature of attentional and emotional processes. A subtle, right-lateralized increase in early LPP amplitude to threatening facial expressions compared to neutral faces in 5- to 8-year-old TDC was also observed. In Experiment 2, differences in N1 and P1 elicitation were observed when comparing CWS and TDC—evidence that childhood stuttering may be associated with selective attention to socially threatening information. No group differences in LPP amplitude were found when directly comparing CWS and TDC. However, when groups were analyzed separately, CWS demonstrated significant ERP modulation to threat and reappraisal conditions, while TDC did not. In accordance with multifactorial theories of childhood stuttering, this study revealed considerable variability in ERP elicition for both CWS and TDC. Fluctuations in ERP amplitude to changes in the emotional salience of child facial expressions may reflect hypersensitivity in the processing of threat for a subset of CWS—a disproportionately large subset of CWS exhibited increased reactivity and regulation effects compared to TDC, particularly those TDC matched with CWS. In addition, these ERP effects to affective facial expressions were not associated with atypical temperament or negative communication attitude