LAUSR

Deficits in auditory processing are an assumed underlying mechanism in stuttering. Previous studies have demonstrated that speech evoked auditory brainstem response (s-ABR) is a reliable method to evaluate brainstem timing in clinical populations with persistent developmental stuttering (PDS). The examination of s-ABR signals to quantify differential complexities between PDS and normal subjects using linear analysis is unreliable. This prompted us to evaluate non-linear methods, which are more effective for conveying complex dynamics. The aim of the current study is to apply fractal dimension and the Hurst exponent to s-ABR signals in order to identify complexity differences between PDS and normal subjects who were stimulated with the synthetic/da/stimulus. Analysis of scaling exponents showed a statistically significant difference between the two groups. The s-ABR signal in subjects with stuttering becomes more complex due to stimulation. These findings are discussed in terms of dysfunctional sub-cortical activation in PDS populations.