An oscillator model better predicts cortical entrainment to music

Abstract

A body of research demonstrates convincingly a role for synchronization of auditory cortex to rhythmic structure in sounds including speech and music. Some studies hypothesize that an oscillator in auditory cortex could underlie important temporal processes such as segmentation and prediction. An important critique of these findings raises the plausible concern that what is measured is perhaps not an oscillator but is instead a sequence of evoked responses. The two distinct mechanisms could look very similar in the case of rhythmic input, but an oscillator might better provide the computational roles mentioned above (i.e., segmentation and prediction). We advance an approach to adjudicate between the two models: analyzing the phase lag between stimulus and neural signal across different stimulation rates. We ran numerical simulations of evoked and oscillatory computational models, showing that in the evoked case,phase lag is heavily rate-dependent, while the oscillatory model displays marked phase concentration across stimulation rates. Next, we compared these model predictions with magnetoencephalography data recorded while participants listened to music of varying note rates. Our results show that the phase concentration of the experimental data is more in line with the oscillatory model than with the evoked model. This finding supports an auditory cortical signal that (i) contains components of both bottom-up evoked responses and internal oscillatory synchronization whose strengths are weighted by their appropriateness for particular stimulus types and (ii) cannot be explained by evoked responses alone.

Frequency selectivity of persistent cortical oscillatory responses to auditory rhythmic stimulation

“…Here, we reveal that such mechanism does not occur during passive perception. Our results are thus incompatible with the idea that the auditory cortex can be modelled as an isolated underdamped harmonic low-frequency (delta) oscillator 30,43 . They are also inconsistent with the idea that beta-band induced activity entrains at the beat rate during passive listening 31 .…”

A silent disco: Differential effects of beat-based and pattern-based temporal expectations on persistent entrainment of low-frequency neural oscillations

“…Entrainment models (Large & Jones, 1999) provide a mechanistic explanation for temporal expectations, by assuming that the phase and period of low-frequency neural oscillations synchronizes to external rhythmic stimulation, causing optimal neural excitability at expected times Schroeder & Lakatos, 2009a). Entrainment theories are corroborated by behavioral evidence showing improved performance for events in phase with an external rhythm (Bouwer & Honing, 2015;Jones, Moynihan, MacKenzie, & Puente, 2002;Large & Jones, 1999), evidence showing the dependency of behavioral performance on the phase of delta oscillations (Arnal, Doelling, & Poeppel, 2014;Cravo, Rohenkohl, Wyart, & Nobre, 2013;Henry, Herrmann, & Obleser, 2014;Henry & Obleser, 2012), and evidence showing phase locking of low frequency oscillations to rhythmic input (Doelling, Assaneo, Bevilacqua, Pesaran, & Poeppel, 2019;Nozaradan, Peretz, Missal, & Mouraux, 2011;Stefanics et al, 2010).…”

Delta phase resets mediate non-rhythmic temporal prediction

“…Our results provide further evidence that phase resets of low-frequency oscillations 520 observed during temporal predictions cannot solely be explained by stimulus-evoked, bottom-521 up brain activity (see also, Doelling et al, 2019;Kösem et al, 2018;ten Oever et al, 2017). In 522 the current study, we aimed at reducing such brain responses to a minimum by presenting 523 participants with a continuously moving stimulus instead of several discrete stimuli.…”

“…Rhythms have the obvious methodological advantage that the temporal structure 56 of the stimulation and therefore the frequencies of the oscillations that should align to the 57 rhythmic stimulation are well-defined. However, rhythmic input also leads to a continuous 58 stream of regularly bottom-up evoked potentials, which are -at least -difficult to distinguish 59 from top-down phase adjusted endogenous neural oscillations within the same frequency 60 (Doelling et al, 2019;Zoefel et al, 2018). In addition, using only rhythmic stimulation lacks the 61 opportunity to link phase adjustments to a more general neural mechanism that predicts the 62 temporal structure of any external input.…”

“…However, rhythmic input also causes evoked brain activity within the same frequency range, 517 which makes it difficult to disentangle streams of evoked activity from entrained endogenous 518 neural oscillations (Doelling et al, 2019;Zoefel et al, 2018). 519…”