The Neural Basis of Stuttering: Phase Synchrony Between Brain Regions Predicts Disfluent Brain States in People Who Stutter

Many of us take our ability to speak for granted, but disfluencies known as stuttering can emerge when children are first learning speech. Stuttering negatively impacts the life quality of people who stutter (PWS) and can lead to social anxiety disorders. Researchers and clinicians are working to understand the nature of stuttering and the factors related to its persistence into adulthood and recovery. Current neurology classifies stuttering as a deficit involving sensorimotor integration during speech production. However, it is unknown whether it is specifically related to brain activity underlying phonological processing during speech preparation or the brain activity occurring while waiting to speak. In this work, we combined high density electroencephalography, source localization, and machine learning to uncover the patterns of functional connectivity that predict fluent vs. disfluent speech on a single trial basis. We demonstrated that stuttering can be predicted from phase synchrony between brain regions during visual fixation while waiting to speak. Fluent vs. disfluent brain states were best predicted by phase synchrony during visual fixation. Taken together, the results of this study support the idea that the neural basis of stuttering is just as related to fluctuations in executive function and attentional control as it is to sensorimotor integration during speech production.