2023 Volume 41 Issue 2 Pages 162-171
This study uses a dual-task experiment and investigates the varied responses of people who stutter (PWS) to delayed auditory feedback (DAF). We engaged PWS (N=10) in a reading-aloud task under DAF while performing simple reaction tasks to tactile and auditory stimuli concurrently. We measured their cerebral blood flow using near-infrared spectroscopy (NIRS) to explore the mechanisms underlying speech disfluency. The study categorized the participants into two groups: those with increased dysfluency (dysfluent increase group, n=8) and those with decreased dysfluency (dysfluent decrease group, n=2) under DAF. Due to the uneven group sizes, we focused our cerebral blood flow analysis on the dysfluent increase group. During DAF, this group demonstrated activation in regions near the right superior frontal gyrus (SFG) and right superior parietal gyrus (SPG). These areas are associated with active attention allocation in tactile conditions. The findings suggest that the dysfluent increase group may prioritize attention on tactile stimuli, thereby diminishing their responsiveness to the altered auditory feedback of their speech. This selective attention might contribute to speech disfluency reduction under DAF.
