Date of Degree
PhD (Doctor of Philosophy)
Speech and Hearing Science
Patricia M. Zebrowski
Both theoretical models and empirical evidence implicate the combined influences of high emotional reactivity and low emotional regulation to exacerbation in children's stuttering behavior (e.g., Conture, Walden, Arnold, Graham, Hartfiled, Karrass, 2006; Conture & Walden, 2012; Karrass et al., 2006). Attentional control is a key factor in both the development and implementation of emotional regulation (Bell & Calkins, 2012; Rueda, Posner, & Rothbart, 2004). The purpose of this study was to investigate attentional control along the distraction process in children who stutter using two event-related potential (ERP) experimental tasks: auditory-auditory distraction and visual search. Eight school-age children who stutter (CWS) and eight school-age children who do not stutter (CWNS) were recruited in this study. Using a Go/No Go paradigm, children in this study were asked to discriminate tone duration in the auditory-auditory distraction task and detect specific visual targets in the visual search task in both the auditory and visual tasks. Behavioral measures included reaction time (RT), hit rate (HR, accuracy) and false alarm (FA), while electrophysiological measures included the peak latency and mean amplitude of the mismatch negativity (MMN), P3a, N2pc and reorientation negativity (RON), and N2pc.
Each ERP component reflects a specific stage along the distraction process: automatic scanning and change detection (MMN), involuntary orientation to deviants (P3a), attentional filtering (N2pc) and voluntary attentional reorientation (RON). The first three components are involved in the sensory/perceptual processing, while the last component is involved in the goal-directed processing (cognitive control for distraction compensation). These behavioral and ERP results were correlated with temperament data obtained from parent-report questionnaires.
There were three main findings. First, CWS, but no CWNS, exhibited a P600 and increased peak latency of the late phase of RON (lRON). The P600 is elicited by violations in rule-governed sequences or the effect of encountering unexpected stimuli, while the lRON reflects evaluation of task-relevant information and motor preparation. The existence of P600 suggests that CWS return and re-evaluate deviants, perhaps due to reduced inhibitory control. As a result, CWS are delayed to start the attentional process reflected by lRON. Second, CWS exhibited a higher rate of false alarms in the auditory-auditory distraction task; this finding confirmed the notion of less efficiency in inhibitory control for CWS. Third, similar to previous research findings, our temperament data also revealed that CWS tended to exhibit relatively high negative affect in combination with relatively low effortful and attentional control, compared to their fluent peers.
Taken together, present findings corroborate previous observations of relatively high emotional reactivity and relatively low efficiency in emotional regulation for CWS, including attentional and inhibitory control. Further, our results reveal that the low attentional control in CWS may result from less efficiency in the goal-directed processing for distraction compensation.
Attentional control, emotional regulation, event-related potentials, Stuttering
xii, 140 pages
Includes bibliographical references (pages 127-140).
Copyright 2014 Fang-Chi Chou