Third party stabilization of unstable coordination in systems of coupled oscillators

The Haken-Kelso-Bunz (HKB) system of equations is a well-developed model for dyadic rhythmic coordination in biological systems. It captures ubiquitous empirical observations of bistability – the coexistence of in-phase and antiphase motion – in neural, behavioral, and social coordination. Recent work by Zhang and colleagues has generalized HKB to many oscillators to account for new empirical phenomena observed in multiagent interaction. Utilising this generalization, the present work examines how the coordination dynamics of a pair of oscillators can be augmented by virtue of their coupling to a third oscillator. We show that stable antiphase coordination emerges in pairs of oscillators even when their coupling parameters would have prohibited such coordination in their dyadic relation. We envision two lines of application for this theoretical work. In the social sciences, our model points toward the development of intervention strategies to support coordination behavior in heterogeneous groups (for instance in gerontology, when younger and older individuals interact). In neuroscience, our model will advance our understanding of how the direct functional connection of mesoscale or microscale neural ensembles might be switched by their changing coupling to other neural ensembles. Our findings illuminate a crucial property of complex systems: how the whole is different than the system’s parts.

The coordination abilities development in female students based on dance exercises

Background and Study Aim. The physical fitness of students is characterized by the level of their abilities development to perform movements of varying complexity. One of the important components in the system of movements is coordination skills. The aim of the study is to identify the level of special and general coordination of students majoring in "Choreography" and provide recommendations for the development of coordination skills in the process of studying modern-jazz dance. Material and Methods. The study involved students of the first and second year of study (n = 10, at the beginning of the study (1 year) age - 17.4 ± 0.7 years) majoring in "Choreography". Tests were used to determine the level of development of general and special coordination skills. The level of coordination readiness at the beginning of training and after three semesters of training was determined. The study was conducted over three semesters (September 2019 - December 2020). Curricula for students’ training do not include the discipline "Physical Education". The development of physical qualities is the task of special subjects in the course of professional training: 16 hours per week. The workload of students in modern-jazz dance was 2 hours a week. Forms of study for a certain period - full-time (70%), online learning (10%), mixed (20%). In September 2019 and in December 2020, the same students passed selected tests. Results. The following significant changes in increasing the coordination level of the abilities were determined: to control temporal and spatial factors of movements; coordination of movements in combination; vestibular stability; musical-rhythmic coordination (p <0.01). The proposed technique assumes that at the first stage of studying modern jazz dance two, three, four centers are coordinated in simultaneous parallel movement. Conclusions. The need to improve the curriculum of modern jazz dance, the introduction of additional courses to the educational program in the major "Choreography". The technical and lexical base of modern jazz dance in combination with special physical training provides opportunities for the coordination skills development in choreographers.

Multi-Timescale Rhythmicity of Blood Glucose and Insulin Delivery Reveals Key Advantages of Hybrid Closed Loop Therapy

Background: Blood glucose and insulin exhibit coordinated daily and hourly rhythms in people without diabetes (nonT1D). Although the presence and stability of these rhythms are associated with euglycemia, it is unknown if they (1) are preserved in individuals with type 1 diabetes (T1D) and (2) vary by therapy type. In particular, Hybrid Closed Loop (HCL) systems improve glycemia in T1D compared to Sensor Augmented Pump (SAP) therapies, but the extent to which either recapitulates coupled glucose and insulin rhythmicity is not well described. In HCL systems, more rapid modulation of glucose via automated insulin delivery may result in greater rhythmic coordination and euglycemia. Such precision may not be possible in SAP systems. We hypothesized that HCL users would exhibit fewer hyperglycemic event, superior rhythmicity, and coordination relative to SAP users. Methods: Wavelet and coherence analyses were used to compare glucose and insulin delivery rate (IDR) within-day and daily rhythms, and their coordination, in 3 datasets: HCL (n = 150), SAP (n = 89), and nonT1D glucose (n = 16). Results: Glycemia, correlation between normalized glucose and IDR, daily coherence of glucose and IDR, and amplitude of glucose oscillations differed significantly between SAP and HCL users. Daily glucose rhythms differed significantly between SAP, but not HCL, users and nonT1D individuals. Conclusions: SAP use is associated with greater hyperglycemia, higher amplitude glucose fluctuations, and a less stably coordinated rhythmic phenotype compared to HCL use. Improvements in glucose and IDR rhythmicity may contribute to the overall effectiveness of HCL systems.

REPP: A robust cross-platform solution for online sensorimotor synchronization experiments

Sensorimotor synchronization (SMS), the rhythmic coordination of perception and action, is a fundamental human skill that supports many behaviors, from daily repetitive routines to the most complex behavioural coordination, including music and dance (Repp 2005; Repp & Su, 2013). Research on SMS has been mostly conducted in the laboratory using finger tapping paradigms, where participants typically tap with their index finger to a rhythmic sequence of auditory stimuli. However, these experiments require equipment with high temporal fidelity to capture the asynchronies between the time of the tap and the corresponding cue event. Thus, SMS is particularly challenging to study with online research, where variability in participants’ hardware and software can introduce uncontrolled latency and jitter into recordings. Here we present REPP (Rhythm ExPeriment Platform), a novel technology for measuring SMS in online experiments that can work efficiently using the built-in microphone and speakers of standard laptop computers. The audio stimulus (e.g., a metronome or a music excerpt) is played through the speakers and the resulting signal is recorded along with participants’ responses in a single channel. The resulting recording is then analyzed using signal processing techniques to extract and align timing cues with high temporal accuracy. This analysis is fully automated and customizable, enabling researchers to monitor online experiments in real time and to implement a wide variety of SMS paradigms. In this paper, we validate REPP through a series of calibration and behavioural experiments. We demonstrate that our technology achieves high temporal accuracy (latency and jitter within 2 ms on average), high test-retest reliability both in the laboratory (r = .87) and online (r = .80), and high concurrent validity (r = .94). We also suggest methods to ensure high data quality in online SMS experiments using REPP while minimizing recruitment costs. REPP can therefore open new avenues for research on SMS that would be nearly impossible in the laboratory, reducing experimental costs while massively increasing the reach, scalability and speed of data collection.

EDWARD NESBIT (b. 1986)A Pretence of Wit (2010; rev. 2012)

This chapter examines British composer Edward Nesbit’s A Pretence of Wit (2010; revised 2012). In this piece, Nesbit has assembled a rich sequence of W. B. Yeats poems that deal with aspects of nature and humanity, and are set with skill and empathy. Wisely, he avoids extremes of vocal range, and contrasts smooth, relatively uncluttered cantabile lines with bursts of fast-moving parlando patterns. The cycle will suit a nimble, bright-voiced soprano—a more dramatic, heavy voice could find the frequent delicate passages difficult to negotiate. Dynamics throughout are used subtly: there are a number of distinctive quirky moments which enliven the articulation of the texts. The elaborate piano parts require a player of fine technique and rhythmic command. Three staves are used at a climactic point in the final movement. Ultimately, achieving rhythmic coordination is probably the most challenging aspect for both performers.

Saliency-based Rhythmic Coordination of Perceptual Predictions

Objects, shown explicitly or held in mind internally, compete for limited processing resources. Recent studies have demonstrated that attention samples locations and objects rhythmically. Interestingly, periodic sampling not only operates over objects in the same scene but also occurs for multiple perceptual predictions that are held in attention for incoming inputs. However, how the brain coordinates perceptual predictions that are endowed with different levels of bottom–up saliency information remains unclear. To address the issue, we used a fine-grained behavioral measurement to investigate the temporal dynamics of processing of high- and low-salient visual stimuli, which have equal possibility to occur within experimental blocks. We demonstrate that perceptual predictions associated with different levels of saliency are organized via a theta-band rhythmic course and are optimally processed in different phases within each theta-band cycle. Meanwhile, when the high- and low-salient stimuli are presented in separate blocks and thus not competing with each other, the periodic behavioral profile is no longer present. In summary, our findings suggest that attention samples and coordinates multiple perceptual predictions through a theta-band rhythm according to their relative saliency. Our results, in combination with previous studies, advocate the rhythmic nature of attentional process.

Entrainment and the Social Origin of Musical Rhythm

Chapter 12 develops Maurice Halbwachs’ concern with social interaction in theorizing rhythm. Taking inspiration from Halbwachs’ view of rhythm as social not natural, the chapter outlines a new approach to the question that Halbwachs leaves unanswered: If musical rhythm is social in origin, how does it come into being—how is his “prior collective agreement” reached? Alfred Schütz, although casting Halbwachs as the straw man in his famous essay “Making Music Together,” did not contest the latter’s point about the social origin of rhythm. Schütz’s argument—that all communication is made possible by what he called the “mutual tuning-in relationship” in which individuals come to share their experience of inner time—does contradict Halbwachs: for Schütz, rhythmic coordination is prior to any collective agreement. The author argues that rhythm in fact emerges spontaneously both in individuals and, crucially, in interactions between them, and that it is therefore both natural (physiological) and social in origin.