Abnormal auditory synchronization in stuttering: A magnetoencephalographic study

• Published in: Hearing research Vol. 344; pp. 82 - 89
• Main Authors: Kikuchi, Yoshikazu, Okamoto, Tsuyoshi, Ogata, Katsuya, Hagiwara, Koichi, Umezaki, Toshiro, Kenjo, Masamutsu, Nakagawa, Takashi, Tobimatsu, Shozo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2017
• Subjects: Acoustic Stimulation; Adult; Auditory Cortex - physiopathology; Auditory Perception; Brain Mapping - methods; Case-Control Studies; Cortical Synchronization; Evoked Potentials, Auditory; Functional Laterality; Humans; Magnetoencephalography; Male; Phase-locking factors; Phase-locking values; Reaction Time; Stuttering; Stuttering - diagnosis; Stuttering - physiopathology; Stuttering - psychology; Synchronization; Time Factors; Young Adult; HPI; Phase-locking factors; AEF; Stuttering; Magnetoencephalography; ECD; DAF; Phase-locking values; PLF; Synchronization; PWS; MEG; fMRI; MC-tSSS; HCs; RMS; PLV
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/j.heares.2016.10.027

In a previous magnetoencephalographic study, we showed both functional and structural reorganization of the right auditory cortex and impaired left auditory cortex function in people who stutter (PWS). In the present work, we reevaluated the same dataset to further investigate how the right and left auditory cortices interact to compensate for stuttering. We evaluated bilateral N100m latencies as well as indices of local and inter-hemispheric phase synchronization of the auditory cortices. The left N100m latency was significantly prolonged relative to the right N100m latency in PWS, while healthy control participants did not show any inter-hemispheric differences in latency. A phase-locking factor (PLF) analysis, which indicates the degree of local phase synchronization, demonstrated enhanced alpha-band synchrony in the right auditory area of PWS. A phase-locking value (PLV) analysis of inter-hemispheric synchronization demonstrated significant elevations in the beta band between the right and left auditory cortices in PWS. In addition, right PLF and PLVs were positively correlated with stuttering frequency in PWS. Taken together, our data suggest that increased right hemispheric local phase synchronization and increased inter-hemispheric phase synchronization are electrophysiological correlates of a compensatory mechanism for impaired left auditory processing in PWS. •People who stutter (PWS) have significantly delayed left-only N100m latency.•PWS have increased local phase synchronization in the alpha band.•PWS show increased inter-hemispheric synchronization in the beta band.•Right hemisphere hyperactivity offsets impaired left hemispheric function in PWS.