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The complexity matching effect supposes that synchronization between complex systems could emerge from multiple interactions across multiple scales and has been hypothesized to underlie a number of daily-life situations. Complexity matching suggests that coupled systems tend to share similar scaling properties, and this phenomenon is revealed by a statistical matching between the scaling exponents that characterize the respective behaviors of both systems. However, some recent papers suggested that this statistical matching could originate from local adjustments or corrections, rather than from a genuine complexity matching between systems. In the present paper, we propose an analysis method based on correlation between multifractal spectra, considering different ranges of time scales. We analyze several datasets collected in various situations (bimanual coordination, interpersonal coordination, and walking in synchrony with a fractal metronome). Our results show that this method is able to distinguish between situations underlain by genuine statistical matching and situations where statistical matching results from local adjustments. [ABSTRACT FROM AUTHOR]

Falls represent a major cause of burden and death in older adults. The MACVIA-LR (fighting chronic diseases for active and healthy ageing in Languedoc-Roussillon) falls initiative is a cross-cutting Living Lab based on the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) at the regional level. It covers all action plans (A1, A2, A3, B3, C2 and D4) of the EIP on AHA. The Living Lab will: (i) raise awareness, (ii) drive attitude change with respect to falls and falls prevention and (iii) improve access to information on falls prevention. It aims to reduce fall-related hospitalisations by 30% in 2020 in the région Languedoc-Roussillon (LR). It includes: (i) a falls prevention clinic for the assessment of subjects (with a falls risk) in the two teaching hospitals of Montpellier and Nîmes, (ii) the Regional Ageing Institute (CARSAT-LR), (iii) the Low Vision Institute of Nîmes, (iv) the Lattes Social Welfare Centre, (v) the home automation Institut méditerranéen des métiers de longévité, (vi) teaching, training and coaching as well as (vii) industrial partnership. Two care pathways have been developed (stroke and falls) and are being applied to remote rural areas of the région. The MACVIA-falls prevention initiative is an output of the EIP on AHA. [ABSTRACT FROM AUTHOR]

A subtle coordination occurs within complex systems, between multiple nested sub-systems. This intra-system coordination can be detected by the presence of 1/ f fluctuations produced by the system. But coordination can occur also between systems. Interpersonal coordination has been studied from a local point of view until now, focusing on macroscopic interactions. But the recent concept of strong anticipation introduced by Dubois (Lect Notes Comput Sci 2684:110-132, ) suggests that interactions could occur on multiple levels between complex systems. The hypothesis is that time series in interpersonal synchronization present a matching of the complexity index (fractal exponent). Moreover, it is argued that this matching is not a consequence of short-term adaptations but reveals a global coordination between participants. Eleven pairs of participants oscillated a hand-held pendulum in the in-phase pattern for 11 min, in three conditions where the coupling strength was manipulated by the perceptual feedbacks. The results show a high correlation between fractal exponents irrespective of the coupling strength, and a very low percentage of local cross-correlations between time series appear at lag 0 and lag 1. These results suggest that interpersonal coordination, and more globally synchronization of participants with natural environments, is based on non-local time scales. [ABSTRACT FROM AUTHOR]

Long-range dependence is a characteristic property of successively produced time intervals, such as in un-paced or continuation tapping. We hypothesise in the present paper that serial dependence in such tasks could be related to a closed-loop regulation process, in which the current interval is determined by preceding ones. As a consequence, the quality of sensory feedback is likely to affect serial dependence. An experiment with human participants shows that diminished sensory information tends to increase the Hurst exponent for short inter-onset intervals and tends to decrease it for long intervals. A simulation shows that a simple auto-regressive model, whose order depends on the ratio between the inter-onset interval and an assumed temporal integration span, is able to account for most of our empirical results, including the duration specificity of long-range correlation. [ABSTRACT FROM AUTHOR]

1/ f β noise has been revealed in both self-paced and synchronized tapping sequences, without being consistently taken into consideration for the modeling of underlying timing mechanisms. In this study we characterize variability, short-range, and long-range correlation properties of asynchronies and inter-tap intervals collected in a synchronization tapping experiment, attesting statistically the presence of 1/ f β noise in asynchronies. We verify that the linear phase correction model of synchronization tapping in its original formulation cannot account for the empirical long-range correlation properties. On the basis of previous accounts of 1/ f β noise in the literature on self-paced tapping, we propose an extension of the original synchronization model by modeling the timekeeping process as a source of 1/ f β fluctuations. Simulations show that this ‘1/ f-AR synchronization model’ accounts for the statistical properties of empirical series, including long-range correlations, and provides an unifying mechanistic account of 1/ f β noise in self-paced and synchronization tapping. This account opens the original synchronization framework to further investigations of timing mechanisms with regard to the serial correlation properties in performed time intervals. [ABSTRACT FROM AUTHOR]

We analyzed the correlation structure of discrete relative phase (DRP) series in bimanual in-phase and anti-phase coordination by associating a number of fractal methods and using discrete rather than continuous relative phase measurement. ARFIMA/ARMA modeling provided statistical evidence for the presence of long-range correlation, and the series were unambiguously characterized as 1 /f β noise. Diverging accounts of bimanual coordination are defended in the literature. Since the evidence for 1 /f β noise provides new insight into the properties of stability in coordination, it should be considered as an empirical criterion for determining which mechanisms are likely to be engaged in bimanual coordination models. We discussed some implications for studying the neural basis of coordination, and we tested the performance of three current models in accounting for 1/ f β noise in DRP. None of these models was proven to generate the expected correlation structure. [ABSTRACT FROM AUTHOR]