AUTHOR=Ghaderi Amir H. , Andevari Masoud N. , Sowman Paul F. 

TITLE=Evidence for a Resting State Network Abnormality in Adults Who Stutter

JOURNAL=Frontiers in Integrative Neuroscience

VOLUME=12

YEAR=2018

URL=https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2018.00016

DOI=10.3389/fnint.2018.00016

ISSN=1662-5145

ABSTRACT=<p>Neural network-based investigations of stuttering have begun to provide a possible integrative account for the large number of brain-based anomalies associated with stuttering. Here we used resting-state EEG to investigate functional brain networks in adults who stutter (<italic>AWS</italic>). Participants were 19 <italic>AWS</italic> and 52 age-, and gender-matched normally fluent speakers. <italic>EEGs</italic> were recorded and connectivity matrices were generated by <italic>LORETA</italic> in the theta (4–8 Hz), alpha (8–12 Hz), beta1 (12–20 Hz), and beta2 (20–30 Hz) bands. Small-world propensity (<italic>SWP</italic>), shortest path, and clustering coefficients were computed for weighted graphs. Minimum spanning tree analysis was also performed and measures were compared by non-parametric permutation test. The results show that small-world topology was evident in the functional networks of all participants. Three graph indices (diameter, clustering coefficient, and shortest path) exhibited significant differences between groups in the theta band and one [maximum betweenness centrality (<italic>BC</italic>)] measure was significantly different between groups in the beta2 band. <italic>AWS</italic> show higher <italic>BC</italic> than control in right temporal and inferior frontal areas and lower <italic>BC</italic> in the right primary motor cortex. Abnormal functional networks during rest state suggest an anomaly of <italic>DMN</italic> activity in <italic>AWS</italic>. Furthermore, functional segregation/integration deficits in the theta network are evident in <italic>AWS</italic>. These deficits reinforce the hypothesis that there is a neural basis for abnormal executive function in <italic>AWS</italic>. Increased beta2 <italic>BC</italic> in the right speech–motor related areas confirms previous evidence that right audio–speech areas are over-activated in <italic>AWS</italic>. Decreased beta2 <italic>BC</italic> in the right primary motor cortex is discussed in relation to abnormal neural mechanisms associated with time perception in <italic>AWS</italic>.</p>