Physiological and Behavioral Factors in Musicians' Performance Tempo

Response to music on the nonlinear dynamics of human fetal heart rate fluctuations: A recurrence plot analysis

Music has been shown to influence physiological functions in humans, but its effects on fetal heart rate variability (fHRV) are not well understood. This study aimed to assess the response of classical music exposure on the nonlinear behavior of fetal heart rate fluctuations in fetuses between 32 and 40 weeks of gestation using recurrence quantification analysis (RQA). We collected R-R time series from 37 fetuses in the third trimester following a study into four stages: PRE (baseline), STIM1 (first musical piece), STIM2 (second musical piece), and POST (post-exposure). The fetal R-R time series from each stage were evaluated using RQA indices such as determinism (DET), average diagonal line length (L), maximum line length (LMAX), entropy (ENTR), and trapping time (TT), as well as conventional linear indices like SDRR (standard deviation of R-R intervals). Results revealed three main points. First, there was an increase in DET, L, LMAX, and TT, with a decrease in ENTR in the POST stage compared to PRE, indicating more regular and predictable patterns. Second, the STIM2 stage enhanced the predictability and stability of cardiac dynamics compared to PRE, as indicated by L, LMAX, and TT. Third, no significant changes were observed in conventional indices, except for an increase in SDRR in the POST stage compared to STIM1. These findings suggest a reduction in complexity and nonlinear behavior of fHRV patterns after musical stimulus. The increase in SDRR during the POST stage appears to coincide with fetal movements, as indicated by the number of fetal accelerations found.

Spontaneous rates exhibit high intra-individual stability across movements involving different biomechanical systems and cognitive demands

Spontaneous rhythmic movements are part of everyday life, e.g., in walking, clapping or music making. Humans perform such spontaneous motor actions at different rates that reflect specific biomechanical constraints of the effector system in use. However, there is some evidence for intra-individual consistency of specific spontaneous rates arguably resulting from common underlying processes. Additionally, individual and contextual factors such as musicianship and circadian rhythms have been suggested to influence spontaneous rates. This study investigated the relative contributions of these factors and provides a comprehensive picture of rates among different spontaneous motor behaviors, i.e., melody production, walking, clapping, tapping with and without sound production, the latter measured online before and in the lab. Participants (n = 60) exhibited high intra-individual stability across tasks. Task-related influences included faster tempi for spontaneous production rates of music and wider ranges of spontaneous motor tempi (SMT) and clapping rates compared to walking and music making rates. Moreover, musicians exhibited slower spontaneous rates across tasks, yet we found no influence of time of day on SMT as measured online in pre-lab sessions. Tapping behavior was similar in pre-lab and in-lab sessions, validating the use of online SMT assessments. Together, the prominent role of individual factors and high stability across domains support the idea that different spontaneous motor behaviors are influenced by common underlying processes.

Which factors modulate spontaneous motor tempo? A systematic review of the literature

Intentionally or not, humans produce rhythmic behaviors (e.g., walking, speaking, and clapping). In 1974, Paul Fraisse defined rhythmic behavior as a periodic movement that obeys a temporal program specific to the subject and that depends less on the conditions of the action (p. 47). Among spontaneous rhythms, the spontaneous motor tempo (SMT) corresponds to the tempo at which someone produces movements in the absence of external stimuli, at the most regular, natural, and pleasant rhythm for him/her. However, intra- and inter-individual differences exist in the SMT values. Even if several factors have been suggested to influence the SMT (e.g., the age of participants), we do not yet know which factors actually modulate the value of the SMT. In this context, the objectives of the present systematic review are (1) to characterize the range of SMT values found in the literature in healthy human adults and (2) to identify all the factors modulating the SMT values in humans. Our results highlight that (1) the reference value of SMT is far from being a common value of 600 ms in healthy human adults, but a range of SMT values exists, and (2) many factors modulate the SMT values. We discuss our results in terms of intrinsic factors (in relation to personal characteristics) and extrinsic factors (in relation to environmental characteristics). Recommendations are proposed to assess the SMT in future research and in rehabilitative, educative, and sport interventions involving rhythmic behaviors.

Spontaneous motor tempo over the course of a week: the role of the time of the day, chronotype, and arousal

The spontaneous motor tempo (SMT) or internal tempo describes the natural pace of predictive and emergent movements such as walking or hand clapping. One of the main research interests in the study of the spontaneous motor tempo relates to factors affecting its pace. Previous studies suggest an influence of the circadian rhythm (i.e., 24-h cycle of the biological clock), physiological arousal changes, and potentially also musical experience. This study aimed at investigating these effects in participants' everyday life by measuring their SMT four times a day over seven consecutive days, using an experience sampling method. The pace of the SMT was assessed with a finger-tapping paradigm in a self-developed web application. Measured as the inter-tap interval, the overall mean SMT was 650 ms (SD = 253 ms). Using multi-level modelling (MLM), results show that the pace of the SMT sped up over the course of the day, and that this effect depended on the participants' chronotype, since participants tending towards morning type were faster in the morning compared to participants tending towards evening type. During the day, the pace of the SMT of morning types stayed relatively constant, whereas it became faster for evening-type participants. Furthermore, higher arousal in participants led to a faster pace of the SMT. Musical sophistication did not influence the SMT. These results indicate that the circadian rhythm influences the internal tempo, since the pace of SMT is not only dependent on the time of the day, but also on the individual entrainment to the 24-h cycle (chronotype).

Endogenous rhythms influence musicians' and non-musicians' interpersonal synchrony

Individuals display considerable rate differences in the spontaneous production of rhythmic behaviors (such as speech, gait, dance). Temporal precision in rhythmic behavior tends to be highest at individuals’ spontaneous production rates; musically trained partners with similar spontaneous rates show increased synchrony in joint tasks, consistent with predictions based on intrinsic frequencies of coupled oscillators. We address whether partner-specific influences of intrinsic frequencies are evidenced in musically trained and untrained individuals who tapped a familiar melody at a spontaneous (uncued) rate individually. Each individual then synchronized with a partner from the same musicianship group at an initially cued rate that matched the partners’ spontaneous rates. Musically trained partners showed greater synchrony in joint tapping than musically untrained partners. Asynchrony increased in both groups as the partners’ difference in individual spontaneous rates increased, with greater impact for musically untrained pairs. Recurrence quantification analysis confirmed that musically untrained individuals demonstrated greater determinism (less flexibility) in their tapping than musically trained individuals. Furthermore, individuals with greater determinism in solo performances demonstrated reduced synchrony in joint performances. These findings suggest that musicians’ increased temporal flexibility is associated with decreased endogenous constraints on production rate and greater interpersonal synchrony in musical tasks.

Does chronotype explain daily timing of music behaviors?

We addressed how circadian rhythms influence daily musical activities of performing musicians, who exhibit fine temporal control. Music performances often occur in the evening and late at night; evidence suggests that composing musicians tend to be later chronotypes than non-composing musicians. However, chronotype and daily music-making in performing musicians have yet to be investigated. The current study examined chronotype in actively practicing and/or performing musicians and non-musicians, and whether it was related to the daily timing of music performance. To test influences of daily changes due to the global COVID-19 pandemic, disruptions to musical, athletic, social, and sleep habits were also measured. Performing musicians, active (practicing but non-performing) musicians, inactive musicians, and non-musicians, residing in Canada, completed a 7-day online daily activity and sleep diary in Summer 2020. There were more evening chronotypes than morning chronotypes in the sample. Active/performing musicians tended to be earlier chronotypes than all other groups. Musicians' chronotype, but not nightly sleep timing, predicted the time of day that musicians made music: Late chronotypes made music later in the day and early chronotypes made music earlier in the day. Music performance and practice amount decreased during the COVID-19 period, but the daily timing of these activities did not change. All participants reported later sleep onset during the COVID-19 period; the amount of social interaction decreased during the COVID-19 period, while exercise increased for some and decreased for others. No changes in the daily timing of exercise, social interaction, or morning wake-up were reported. These findings suggest that performing musicians may be slightly earlier chronotypes than non-performing musicians and non-musicians, despite music performances often occurring in the evening. Chronotype was related to the time of day of music-making independent of nightly sleep timing, suggesting that times of day for making music reflect an individual's circadian rhythm.

Behavioral and Neural Dynamics of Interpersonal Synchrony Between Performing Musicians: A Wireless EEG Hyperscanning Study

Interpersonal synchrony refers to the temporal coordination of actions between individuals and is a common feature of social behaviors, from team sport to ensemble music performance. Interpersonal synchrony of many rhythmic (periodic) behaviors displays dynamics of coupled biological oscillators. The current study addresses oscillatory dynamics on the levels of brain and behavior between music duet partners performing at spontaneous (uncued) rates. Wireless EEG was measured from N = 20 pairs of pianists as they performed a melody first in Solo performance (at their spontaneous rate of performance), and then in Duet performances at each partner's spontaneous rate. Influences of partners' spontaneous rates on interpersonal synchrony were assessed by correlating differences in partners' spontaneous rates of Solo performance with Duet tone onset asynchronies. Coupling between partners' neural oscillations was assessed by correlating amplitude envelope fluctuations of cortical oscillations at the Duet performance frequency between observed partners and between surrogate (re-paired) partners, who performed the same melody but at different times. Duet synchronization was influenced by partners' spontaneous rates in Solo performance. The size and direction of the difference in partners' spontaneous rates were mirrored in the size and direction of the Duet asynchronies. Moreover, observed Duet partners showed greater inter-brain correlations of oscillatory amplitude fluctuations than did surrogate partners, suggesting that performing in synchrony with a musical partner is reflected in coupled cortical dynamics at the performance frequency. The current study provides evidence that dynamics of oscillator coupling are reflected in both behavioral and neural measures of temporal coordination during musical joint action.

Effects of music on the cardiovascular system

Although music is predominantly utilized for religious, enjoyment or entertainment purposes, it is gradually emerging as a promising non-pharmacological intervention for improving health outcomes in both healthy and diseased populations, especially in those with cardiovascular diseases. As such, music of various genres and types has been postulated to possess features that stimulate or inhibit the autonomic nervous system, which leads to variable effects on cardiovascular function. However, music intervention has not been adequately explored as a cardiovascular therapeutic modality due to the lack of extensive studies with quality methodology. Thus, the aim of this systematic review is to explore the available literature on the effect of music on the cardiovascular system, discuss the limitations of current research, and suggest future directions in this field.

Spontaneous Production Rates in Music and Speech

Individuals typically produce auditory sequences, such as speech or music, at a consistent spontaneous rate or tempo. We addressed whether spontaneous rates would show patterns of convergence across the domains of music and language production when the same participants spoke sentences and performed melodic phrases on a piano. Although timing plays a critical role in both domains, different communicative and motor constraints apply in each case and so it is not clear whether music and speech would display similar timing mechanisms. We report the results of two experiments in which adult participants produced sequences from memory at a comfortable spontaneous (uncued) rate. In Experiment 1, monolingual pianists in Buffalo, New York engaged in three production tasks: speaking sentences from memory, performing short melodies from memory, and tapping isochronously. In Experiment 2, English-French bilingual pianists in Montréal, Canada produced melodies on a piano as in Experiment 1, and spoke short rhythmically-structured phrases repeatedly. Both experiments led to the same pattern of results. Participants exhibited consistent spontaneous rates within each task. People who produced one spoken phrase rapidly were likely to produce another spoken phrase rapidly. This consistency across stimuli was also found for performance of different musical melodies. In general, spontaneous rates across speech and music tasks were not correlated, whereas rates of tapping and music were correlated. Speech rates (for syllables) were faster than music rates (for tones) and speech showed a smaller range of spontaneous rates across individuals than did music or tapping rates. Taken together, these results suggest that spontaneous rate reflects cumulative influences of endogenous rhythms (in consistent self-generated rates within domain), peripheral motor constraints (in finger movements across tapping and music), and communicative goals based on the cultural transmission of auditory information (slower rates for to-be-synchronized music than for speech).