Non-linguistic auditory processing in stuttering: evidence from behavior and event-related brain potentials.

UNLABELLED

Auditory processing deficits are hypothesized to play a role in the disorder of stuttering (e.g. Hall, J. W., & Jerger, J. (1978). Central auditory function in stutterers. Journal of Speech and Hearing Research, 21, 324-337). The current study focused on non-linguistic auditory processing without verbal responses to explore the relationship between behavior and neural activity in the absence of cognitive demands related to language processing and articulatory planning for speaking. A pure-tone, oddball paradigm was utilized to compare behavioral accuracy and reaction times for adults who stutter (AWS) and normally fluent speakers (NFS). Additionally, event-related potentials elicited by brief standard and target tones were compared for the two groups. Results revealed that, as a group, AWS tended to perform less accurately compared to the NFS and were slower to respond to target stimuli. However, inspection of individual data indicated that most of the AWS performed within the range of normally fluent speakers while a small subset of AWS were well outside the normal range. This subgroup of AWS also demonstrated early perceptual processes (as indexed by N100 and P200 amplitudes) indicative of reduced cortical representation of auditory input. The P300 mean amplitudes elicited in AWS tended to be reduced overall compared to those of the NFS, suggesting the possibility of weaker updates in working memory for representations of the target tone stimuli in AWS. Taken together, these findings point to the possibility that a subset of AWS exhibit non-linguistic auditory processing deficits related to altered cortical processing.

EDUCATIONAL OBJECTIVES

After reading this article, the reader will be able to: (1) summarize research findings of non-linguistic auditory processing in stuttering; (2) discuss the relationship between behavioral performance for auditory processing and the underlying event-related brain potentials; (3) discuss the importance of analyses of individual versus group data in stuttering; and (4) summarize how the findings of this study relate to a multifactorial model of stuttering.