Investigating the social behavioral dynamics and differentiation of skill in a martial arts technique

Interpersonal sensorimotor communication shapes intrapersonal coordination in a musical ensemble

Social behaviors rely on the coordination of multiple effectors within one's own body as well as between the interacting bodies. However, little is known about how coupling at the interpersonal level impacts coordination among body parts at the intrapersonal level, especially in ecological, complex, situations. Here, we perturbed interpersonal sensorimotor communication in violin players of an orchestra and investigated how this impacted musicians' intrapersonal movements coordination. More precisely, first section violinists were asked to turn their back to the conductor and to face the second section of violinists, who still faced the conductor. Motion capture of head and bow kinematics showed that altering the usual interpersonal coupling scheme increased intrapersonal coordination. Our perturbation also induced smaller yet more complex head movements, which spanned multiple, faster timescales that closely matched the metrical levels of the musical score. Importantly, perturbation differentially increased intrapersonal coordination across these timescales. We interpret this behavioral shift as a sensorimotor strategy that exploits periodical movements to effectively tune sensory processing in time and allows coping with the disruption in the interpersonal coupling scheme. As such, head movements, which are usually deemed to fulfill communicative functions, may possibly be adapted to help regulate own performance in time.

Combat as an Interpersonal Synergy: An Ecological Dynamics Approach to Combat Sports

In combat sports, athletes continuously co-adapt their behavior to that of the opponent. We consider this interactive aspect of combat to be at the heart of skilled performance, yet combat sports research often neglects or limits interaction between combatants. To promote a more interactive approach, the aim of this paper is to understand combat sports from the combined perspective of ecological psychology and dynamic systems. Accordingly, combat athletes are driven by perception of affordances to attack and defend. Two combatants in a fight self-organize into one interpersonal synergy, where the perceptions and actions of both athletes are coupled. To be successful in combat, performers need to manipulate and take advantage of the (in)stability of the system. Skilled performance in combat sports therefore requires brinkmanship: combatants need to be aware of their action boundaries and purposefully act in meta-stable regions on the limits of their capabilities. We review the experimental literature to provide initial support for a synergetic approach to combat sports. Expert combatants seem able to accurately perceive action boundaries for themselves and their opponent. Local-level behavior of individual combatants has been found to lead to spatiotemporal synchronization at the global level of a fight. Yet, a formal understanding of combat as a dynamic system starting with the identification of order and control parameters is still lacking. We conclude that the ecological dynamics perspective offers a promising approach to further our understanding of skilled performance in combat sports, as well as to assist coaches and athletes to promote optimal training and learning.

The anatomy of antagonistic coregulation: Emergent coordination, path dependency, and the interplay of biomechanic parameters in Aikido

Using a video-supported cognitive ethnographic and phenomenological approach, we address the interactively generated dynamic of bouts in Aikido. This "soft" martial art enables a defender to blend with and then redirect an attacker's aggressive energy so as to break his balance, while preserving an ethos of non-violence, mutuality, and respect. Our analysis explores the skills used to minutely adapt to the opponent, the causal-temporal structure of Aikido, notably the cumulative effect build-up and main decision points in a bout, as well as the perceptual cues from inter-body geometry, timing, and force dynamics that inform decisions. We then contrast different interaction scenarios by focusing on micro-events that shape defensive preferences. For a successful defense, technical modulations or even the preferred technique itself can be selected as the interaction unfolds ("decision-making-in-action"). For a closer look, we analyze the interplay of multiple parameters: flexibility of intention (i.e. early deciding vs. keeping options openlonger), technique (i.e. type of lever or throw), initial body symmetry, step combinations, spacing and timing relative to the attacker, degree of force, as well as possible skill differentials. We describe complex interdependencies between these parameters, which can be balanced in various ways as agents respond to the interaction dynamic.