Induced Beta Power Modulations during Isochronous Auditory Beats Reflect Intentional Anticipation before Gradual Tempo Changes

Abstract

been related to beat processing and timing prediction. In passively listening to auditory beats, beta ERD consistently occurred after stimuli regardless of their tempo 8 , likely representing obligatory stimulus processing 14. Beta ERS following this ERD peaked predictively around the time of the next beat for beat intervals between 390 and 780 ms, adjusting its time course to the tempo of the stimuli 8. For visual events occurring at slower tempos, however, no clear relationship between beta ERS rates and tempo have been found, making it necessary to investigate the previously found patterns further 15. Nevertheless, beta power modulations for auditory stimuli at musical tempos, like those that were used in the current study, reflect the processing of beats and automatic prediction for subsequent beats according to the surrounding tempo. Beta power modulations are also affected by high-level processes like attention, uncertainty, expectation, and imagery, all potentially involved in temporal anticipation. For attention, Todorovic et al. 11 showed that beta power ERD before an actively attended tone tended to be smaller than that before an unattended tone in auditory tone-pair stimuli. When sufficient attention was paid to determine whether an auditory target was on time or delayed, beta ERS was enhanced immediately before the target 16. Attention focused on a particular stimulus during an isochronous visual sequence enhanced beta ERS at the attended time point 17. Beta ERS also peaked around the learned time of attended warning cues in delayed go paradigms 14,18. Apart from the effect of attention, Tzagarakis et al. 19 found that uncertainty about the spatial position of an upcoming visual target greatly reduced typical beta ERD. Similar attenuation of beta ERD was shown during a build-up of expectation for a pitch deviant in an oddball paradigm when a target was overdue to occur after standard tones 20. Finally, imagined metric structures imposed on unaccented isochronous auditory stimuli increased beta ERD strength during the imagined accented beats 12. Since these various high-level, endogenous processes are expressed in beta power modulations and may be expressed simultaneously as a superposition 14 , it is conceivable that temporal anticipation before tempo changes will also be expressed in beta power modulations if such anticipation involves high-level processes like those mentioned above. Thus, we hypothesised that in anticipation of upcoming tempo changes, beta power modulations patterns may be different from those when no tempo changes are anticipated because the latter would require fewer high-level, top-down processes than the former. Further, we hypothesised that whether anticipation for different tempo changes affects ERD, ERS or both, will depend on which high-level process dominates in anticipation and when during the beat period the process takes place. Two main possibilities exist. First, if anticipation is predominantly a local predictive process where slightly early or late beats are predicted...

Predicting the Beat Bin: Beta Oscillations Predict the Envelope Sharpness in a Rhythmic Sequence

“…This corresponds to the time period 1.6–2.28 s relative to the first entraining sound. Based on previous studies investigating beat perception and temporal processing (Arnal et al, 2015; Fujioka et al, 2015, 2012; Fujioka and Ross, 2017; Graber and Fujioka, 2020; Morillon and Baillet, 2017), which reported a positive relationship between beta power and perceptual timing performance or predictive timing, we also expected a beta power increase for the sharp cue condition in our data. The statistical contrast (one-sided cluster-based permutation test, n = 19) between sharp versus smooth cue conditions revealed that beta power was significantly enhanced for the cue condition predicting a sharp target sound.…”

“…This corresponds to the time period 1.6-2.28 s relative to the first entraining sound. Based on previous studies investigating beat perception and temporal processing (Arnal et al, 2015;Fujioka et al, 2015Fujioka et al, , 2012Fujioka and Ross, 2017;Graber and Fujioka, 2020;Morillon and Baillet, 2017), which reported a positive relationship between beta power and perceptual timing performance or predictive timing, we also expected a beta power increase for the sharp cue condition in our data.…”