Synchronization of gamma oscillations among brain regions is relevant for dynamically organizing communication among neurons to support cognitive and perceptual processing, including attention orienting. Recent research has demonstrated that inter-regional synchronization in the gamma-band is modulated by theta rhythms during cortical processing. It has been proposed that such cross-frequency dynamics underlie the integration of local processes into large-scale functional networks. To investigate the potential role of theta-gamma mechanisms during auditory attention control, we localized activated regions using EEG beamformer analysis, and calculated inter-regional gamma-band synchronization between activated regions as well as modulation of inter-regional gamma-band synchronization by the phase of cortical theta rhythms. Abundant synchronization of gamma-band oscillations among regions comprising the auditory attention control network was observed. This inter-regional gamma synchronization was modulated by theta phase. These results provide further evidence implicating inter-regional gamma-band synchronization, and theta-gamma interactions, in task-dependent communication among cortical regions, and provide the first evidence that such mechanisms are relevant for auditory attention control.
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