Journal article

Publication year: 2019

Journal: PLoS ONE

Volume number: 14

Issue number: 4

ISSN: 1932-6203

Open access status: Gold

DOI Link: https://doi.org/10.1371/journal.pone.0213996

Publisher: Public Library of Science

Abstract: 
Synchronized oscillatory gamma-band activity (30-100Hz) has been suggested to constitute a key mechanism to dynamically orchestrate sensory information integration across multiple spatio-temporal scales. We here tested whether interhemispheric functional connectivity and ensuing auditory perception can selectively be modulated by high-density transcranial alternating current stimulation (HD-tACS). For this purpose, we applied multi-site HD-tACS at 40Hz bilaterally with a phase lag of 180 degrees and recorded a 64-channel EEG to study the oscillatory phase dynamics at the source-space level during a dichotic listening (DL) task in twenty-six healthy participants. In this study, we revealed an oscillatory phase signature at 40Hz which reflects different temporal profiles of the phase asymmetries during left and right ear percept. Here we report that 180 degrees-tACS did not affect the right ear advantage during DL at group level. However, a follow-up analysis revealed that the intrinsic phase asymmetries during sham-tACS determined the directionality of the behavioral modulations: While a shift to left ear percept was associated with augmented interhemispheric asymmetry (closer to 180 degrees), a shift to right ear processing was elicited in subjects with lower asymmetry (closer to 0 degrees). Crucially, the modulation of the interhemispheric network dynamics depended on the deviation of the tACS-induced phase-lag from the intrinsic phase asymmetry. Our characterization of the oscillatory network trends is giving rise to the importance of phase-specific gamma-band coupling during ambiguous auditory perception, and emphasizes the necessity to address the inter-individual variability of phase asymmetries in future studies by tailored stimulation protocols.

Harvard Citation style: Meier, J., Nolte, G., Schneider, T., Engel, A., Leicht, G. and Mulert, C. (2019) Intrinsic 40Hz-phase asymmetries predict tACS effects during conscious auditory perception, PLoS ONE, 14(4), Article e0213996. https://doi.org/10.1371/journal.pone.0213996

APA Citation style: Meier, J., Nolte, G., Schneider, T., Engel, A., Leicht, G., & Mulert, C. (2019). Intrinsic 40Hz-phase asymmetries predict tACS effects during conscious auditory perception. PLoS ONE. 14(4), Article e0213996. https://doi.org/10.1371/journal.pone.0213996