Showing papers by "Benoît G. Bardy published in 2015"
TL;DR: It is shown that the IMS of a person is time-invariant and that it significantly differs from those of other individuals, which allows us to quantify the dynamic similarity, a measure of rapport between dynamics of different individuals' movements, and demonstrate that it facilitates coordination during interaction.
Abstract: Human movement has been studied for decades and dynamic laws of motion that are common to all humans have been derived. Yet, every individual moves differently from everyone else (faster/slower, harder/smoother etc). We propose here an index of such variability, namely an individual motor signature (IMS) able to capture the subtle differences in the way each of us moves. We show that the IMS of a person is time-invariant and that it significantly differs from those of other individuals. This allows us to quantify the dynamic similarity, a measure of rapport between dynamics of different individuals' movements, and demonstrate that it facilitates coordination during interaction. We use our measure to confirm a key prediction of the theory of similarity that coordination between two individuals performing a joint-action task is higher if their motions share similar dynamic features. Furthermore, we use a virtual avatar driven by an interactive cognitive architecture based on feedback control theory to explore the effects of different kinematic features of the avatar motion on the coordination with human players.
72 citations
TL;DR: It is suggested that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia, that self-generated movement can generate these higher- order patterns, and that these patterns can be detected and used to support perception of egOCentric distance that is precise and accurate.
Abstract: Body movement influences the structure of multiple forms of ambient energy, including optics and gravito-inertial force. Some researchers have argued that egocentric distance is derived from inferential integration of visual and non-visual stimulation. We suggest that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia. We formalize a pattern that specifies the egocentric distance of a stationary object across higher-order relations between optics and inertia. This higher-order parameter is created by self-generated movement of the perceiver in inertial space relative to the illuminated environment. For this reason, we placed minimal restrictions on the exploratory movements of our participants. We asked whether humans can detect and use the information available in this higher-order pattern. Participants judged whether a virtual object was within reach. We manipulated relations between body movement and the ambient structure of optics and inertia. Judgments were precise and accurate when the higher-order optical-inertial parameter was available. When only optic flow was available, judgments were poor. Our results reveal that participants perceived egocentric distance from the higher-order, optical-inertial consequences of their own exploratory activity. Analysis of participants’ movement trajectories revealed that self-selected movements were complex, and tended to optimize availability of the optical-inertial pattern that specifies egocentric distance. We argue that accurate information about egocentric distance exists in higher-order patterns of ambient energy, that self-generated movement can generate these higher-order patterns, and that these patterns can be detected and used to support perception of egocentric distance that is precise and accurate.
42 citations
TL;DR: The findings provide the evidence that physical attractiveness genuinely affects how people interact with another person, and that the temporal-spatial coordinated movement varies with the partner's psychosocial characteristics.
34 citations
TL;DR: In this article, the authors evaluated the socio-motor competence and the feeling of connectedness between dyads of patients and their synchronization partners with a measure of motor coordination stability.
Abstract: What leads healthy individuals to abnormal feelings of contact with schizophrenia patients remains obscure. Despite recent findings that human bonding is an interactive process influenced by coordination dynamics, the spatiotemporal organization of the bodily movements of schizophrenia patients when interacting with other people is poorly understood. Interpersonal motor coordination between dyads of patients (n = 45) or healthy controls (n = 45), and synchronization partners (n = 90), was assessed with a hand-held pendulum task following implicit exposure to pro-social, non-social, or anti-social primes. We evaluated the socio-motor competence and the feeling of connectedness between participants and their synchronization partners with a measure of motor coordination stability. Immediately after the coordination task, all participants were also asked to rate the likeableness of their interacting partner. Our results showed greater stability during interpersonal synchrony in schizophrenia patients who received pro-social priming, inducing in their synchronization partner greater feelings of connectedness towards patients. This greater feeling of connectedness was positively correlated with stronger motor synchronization between participants suggesting that motor coordination partly underlies patients' social interactions and feelings of contact with others. Pro-social priming can have a pervasive effect on abnormal social interactions in schizophrenia patients.
33 citations
TL;DR: A formal analysis of LRC is presented, exploiting tools from synchronization theories and nonlinear dynamics, and results obtained with a simple rhythmic metronome beat have consequences for exercising while listening to music.
Abstract: In humans and other animals, the locomotor and respiratory systems are coupled together through mechanical, neurophysiological, and informational interactions. At a macroscopic observer-environment level, these three types of interactions produce locomotor-respiratory coupling (LRC), whose dynamics are evaluated in this paper. A formal analysis of LRC is presented, exploiting tools from synchronization theories and nonlinear dynamics. The results of two recent studies, in which participants were instructed to cycle or exhale at a natural frequency or in synchrony with an external rhythmic sound, are discussed. The metronome was either absent or present (study 1) and close to or far from the natural frequency of the cycling and breathing systems (study 2). The results evidenced a stabilization of cycling, breathing, and LRC when sound was present compared to when it was absent. A decrease in oxygen consumption was also observed, accompanying the increase in sound-induced LRC stabilization. These results obtained with a simple rhythmic metronome beat have consequences for exercising while listening to music; the consequences are further explored here.
28 citations
TL;DR: Postural activity differed between body axes as a function of body orientation relative to the ship, and coupling differed between participants who had been seasick at the beginning of the voyage and those who had not.
Abstract: On land, body sway during stance becomes coupled with imposed oscillations of the illuminated environment or of the support surface. This coupling appears to have the function of stabilizing the body relative to the illuminated or inertial environment. In previous research, the stimulus has been limited to motion in a single axis. Little is known about our ability to couple postural activity with complex, multi-axis oscillations. On a ship at sea, we evaluated postural activity using measures of body movement, as such, and we separately evaluated a direct measure of coupling between body movement and ship motion. Participants were tested while facing fore-aft and athwartship. We compared postural activity between participants who had been seasick at the beginning of the voyage and those who had not. Coupling of postural activity with ship motion differed between body axes as a function of body orientation relative to the ship. In addition, coupling differed between participants who had been seasick at the beginning of the voyage and those who had not. We discuss the results in terms of implications for general theories of postural control, and for prediction of susceptibility to seasickness in individuals.
22 citations
TL;DR: The results suggest that LRC is not unidirectional—from locomotion onto respiration—but bidirectional between the two systems, and suggest that auditory information plays an important role in the modulation of LRC.
Abstract: The locomotor–respiratory coupling (LRC) is a universal phenomenon reported for various forms of rhythmic exercise. In this study, we investigated the effect of movement and respiratory frequencies on LRC. Participants were instructed to cycle or breath in synchrony with a periodic auditory stimulation at preferred and non-preferred frequencies. LRC stability was assessed by frequency and phase coupling indexes using the theory of nonlinear coupled oscillators through the sine circle map model, and the Farey tree. Results showed a stabilizing effect of sound on LRC for all frequencies and for the two systems paced. The sound-induced effect was more prominent when the rhythm of the stimulation corresponded to the preferred frequencies. The adoption of cycling or respiratory frequencies far off preferential ones led to a loss of stability in LRC. Contrary to previous findings, our results suggest that LRC is not unidirectional—from locomotion onto respiration—but bidirectional between the two systems. They also suggest that auditory information plays an important role in the modulation of LRC.
13 citations
TL;DR: It is revealed that the HKB model supports previously unreported dynamical regimes as well as bistability between a variety of coordination patterns, and the stability boundaries of distinct coordination regimes in the model are identified.
Abstract: In 1985 Haken, Kelso and Bunz proposed a system of coupled nonlinear oscillators as a model of rhythmic movement patterns in human bimanual coordination. Since then, the Haken-Kelso-Bunz (HKB) model has become a modelling paradigm applied extensively in all areas of movement science, including interpersonal motor coordination. However all previous studies have followed the line of analysis based on the slow varying amplitude and rotating wave approximations. These approximations lead to a reduced system comprised of a single differential equation representing the evolution of the relative phase of the two coupled oscillators. Here we take a different approach and systematically investigate the behaviour of the HKB model in the full four-dimensional state space. We perform detailed numerical bifurcation analyses and reveal that the HKB model supports previously unreported dynamical regimes as well as bi-stability between a variety of coordination patterns. Furthermore, we identify the stability boundaries of distinct coordination regimes in the model and discuss the applicability of our findings to interpersonal coordination and other joint-action tasks.
9 citations
Posted Content•
TL;DR: In this paper, the authors considered a heterogeneous network of Haken-KelsoBunz (HKB) nonlinear oscillators coupled through both linear and nonlinear interaction protocols.
Abstract: In this paper we consider a heterogeneous network of Haken-KelsoBunz (HKB) nonlinear oscillators coupled through both linear and nonlinear interaction protocols. While some work exists on a system made up of only two nonlinearly coupled HKB oscillators as a model of human dynamics during interpersonal coordination tasks, the problem of considering a network of three or more HKBs has not been fully investigated. The aim of our work is to study convergence and synchronization in networks of HKB oscillators as a paradigm of coordination in multiplayer games. Convergence results are obtained under the assumption that the network is connected, simple and undirected. Analytical results are obtained to prove convergence when the oscillators are coupled diffusively. All theoretical results are illustrated via numerical examples. Finally, the effects of adding an external entrainment signal to all the agents in the network are analyzed and a model to account for them is proposed.
5 citations
TL;DR: Le site de reference du Partenariat europeen d'innovation pour un vieillissement actif et en bonne sante MACVIA-LR (contre les maladies chroniques pour un rômant en Languedoc-Roussillon)
Abstract: Le site de reference du Partenariat europeen d'innovation pour un vieillissement actif et en bonne sante MACVIA-LR (contre les maladies chroniques pour un vieillissement en bonne sante en Languedoc-Roussillon)
5 citations
TL;DR: La Presse Medicale - In Press reports on the clinical trials of six new drugs for central nervous system disorders that have shown promising results in women and young people with learning disabilities.
Abstract: La Presse Medicale - In Press.Proof corrected by the author Available online since vendredi 16 octobre 2015
TL;DR: La Presse Medicale - In Press. Available online since vendredi 16 octobre 2015 as discussed by the authors, with proof corrected by the author available online since 16 octoberre 2015
Abstract: La Presse Medicale - In Press.Proof corrected by the author Available online since vendredi 16 octobre 2015
TL;DR: In this article, the authors presented a study on the use of stimuli auditifs discrets generes par un metronome for synchronisation of mouvements rythmiques.
Abstract: Introduction L’utilisation de stimuli auditifs discrets generes par un metronome pour la synchronisation de mouvements rythmiques est connue pour ameliorer la stabilite locale (diminution de la variabilite du mouvement appelee ancrage) et la stabilite globale des coordinations (retard de la transition de patrons). Neanmoins, les travaux portant sur la synchronisation posturale avec une information exterieure se sont principalement cantonnes a une stimulation continue, illustrant alors les caracteristiques dynamiques du systeme postural. L’objectif de cette etude etait de montrer l’interet d’une synchronisation posturale avec un environnement auditif discret et les benefices qui l’accompagnent. Materiel et methode Vingt adultes se tenaient debout dans une position confortable, equipes d’un casque audio. Premierement, ils etaient exposes a l’ecoute d’un metronome a differentes frequences : silence ; 0,25 Hz ; 0,50 Hz ; 1 Hz (synchronisation non-intentionnelle). Deuxiemement, ils devaient synchroniser leurs mouvements posturaux dans le plan antero-posterieur pour chaque « bip » du metronome (synchronisation intentionnelle). Resultats Nos resultats montrent qu’un environnement auditif discret est propice a une synchronisation du systeme postural. Les effets etaient majores lorsque la frequence de stimulation etait proche de celle des oscillations posturales naturelles du sujet. Par ailleurs, un phenomene d’ancrage (augmentation de la regularite du mouvement) ainsi qu’un retard de transition de patrons de coordination (phase vers antiphase) etaient observes dans la condition intentionnelle aux frequences les plus basses. Discussion–conclusion Notre etude suggere ainsi que l’utilisation de stimuli auditifs discrets permet d’augmenter la stabilite dynamique de la posture.
TL;DR: The results suggest that 1) this specific tracking behavior pattern might contribute to self-face recognition impairment and 2) schizophrenia patients explored their own face in a particularly different way.
TL;DR: It is demonstrated that schizophrenic patients have a specific relational motor signature that may lead to the development of rehabilitation protocols improving social motor coordination and successful social exchanges of patients.
TL;DR: In this paper, the authors investigated whether interpersonal coordination is influenced by the physical attractiveness of virtual agents and found that physically attractive agents can help to foster a more stable coordination, thus motivating patients to adhere more to rehabilitation.
TL;DR: In this paper, a two-by-two experimental design was used to evaluate motor and social competences in dyads of healthy and non-healthy participants in a mirror game task.