Violation of rhythmic expectancies can elicit late frontal gamma activity nested in theta oscillations

• Main Authors: Edalati, M. (Author), Mahmoudzadeh, M. (Author), Moghimi, S. (Author), Safaie, J. (Author), Wallois, F. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adult; Adult; anticipation; Anticipation, Psychological; auditory evoked potential; Auditory Perception; event related potential; event-related potential; Event-Related Potentials, P300; Evoked Potentials, Auditory; female; Female; frontal lobe; Frontal Lobe; gamma rhythm; Gamma Rhythm; hearing; human; Humans; male; Male; mismatch negativity; phase-amplitude coupling; physiology; prediction error; predictive coding; theta rhythm; Theta Rhythm; time perception; Time Perception; young adult; Young Adult
• Online Access: View Fulltext in Publisher

 Rhythm processing involves building expectations according to the hierarchical temporal structure of auditory events. Although rhythm processing has been addressed in the context of predictive coding, the properties of the oscillatory response in different cortical areas are still not clear. We explored the oscillatory properties of the neural response to rhythmic incongruence and the cross-frequency coupling between multiple frequencies to further investigate the mechanisms underlying rhythm perception. We designed an experiment to investigate the neural response to rhythmic deviations in which the tone either arrived earlier than expected or the tone in the same metrical position was omitted. These two manipulations modulate the rhythmic structure differently, with the former creating a larger violation of the general structure of the musical stimulus than the latter. Both deviations resulted in an MMN response, whereas only the rhythmic deviant resulted in a subsequent P3a. Rhythmic deviants due to the early occurrence of a tone, but not omission deviants, seemed to elicit a late high gamma response (60–80 Hz) at the end of the P3a over the left frontal region, which, interestingly, correlated with the P3a amplitude over the same region and was also nested in theta oscillations. The timing of the elicited high-frequency gamma oscillations related to rhythmic deviation suggests that it might be related to the update of the predictive neural model, corresponding to the temporal structure of the events in higher-level cortical areas. © 2021 The Authors. Psychophysiology published by Wiley Periodicals LLC on behalf of Society for Psychophysiological Research.