|
Coordinated patterns: Experimental and formal approaches| old_uid | 810 |
|---|
| title | Coordinated patterns: Experimental and formal approaches |
|---|
| start_date | 2006/03/09 |
|---|
| schedule | 13h45-16h |
|---|
| online | no |
|---|
| summary | Meaningful (perceptual-motor) behavior requires the coordination between the different constituting parts of the organism as well as with its surroundings. Coming to terms with the creation and modification of patterns of coordination is at the heart of Coordination Dynamics. In this presentation we will discuss several studies that illustrate research from the perspective of Coordination Dynamics – in particular with respect to the coupling between components and the informational character of coordination, and outline our future approach to develop its theoretical foundations.
In a series of studies, the coordination between the hand/ball movements, point-of-gaze (POG), centre-of-pressure (COP), and respiration was examined as a function of learning to juggle and juggling skill in order to identify the couplings between subsystems and to study how patterns of coordination underlie successful performance. Different aspects of juggling performance were identified that increased monotonically at different rates, suggesting that the learning involved a temporal hierarchy and that the subsystems remained autonomous to some extent. In addition, a few qualitatively distinct coordination modes between the ball/hand movements and POG and COP were observed as well as abrupt changes between them. The changes in ball/hand - POG coordination suggested that learning to juggle involved a shift in the relative importance of different perceptual modalities. The ball/hand - COP coordination was modelled in terms of mechanics. No relation between juggling and respiration was observed. In another study the coordination between rowing and breathing was examined and several coordination modes were found. A dynamical model was formulated to account for these patterns, which suggested that the synchronization of breathing to rowing (or locomotion, more generally) is driven by optimization of the effective volume of oxygen in the lungs. Together, these studies indicate that the coordination between subsystems may be multi-stable (indicating motor-equivalence) and suggests that the coupling between them may be governed by mechanical, informational and energetic constraints.
In underlying successful performance, coordinative patterns are informational quantities. Coordination Dynamics holds that the relevant information for biological motion perception resides in the dynamical features of observed macroscopic patterns, a premise that was examined in the context of anticipation of tennis shots. Whole-body movements of shots to different directions and distances were analyzed in terms of principal components, and it was found that the shots differed in the few components that captured most of the variance, especially as a function of shot direction. In subsequent experiments, skilled and less skilled tennis players indicated shot direction of simulated shots in which only dynamical features were manipulated. The results indicated that a few low-dimensional dynamical components inform about shot direction and suggested that anticipation skill entails the extraction of these dynamics from high-dimensional displays.
The above readily illustrate different aspects to coordination in both rhythmic and discrete movements from the perspective of Coordination Dynamics. To this date, however, a unifying framework to the understanding of coordination phenomena is lacking. We aim to develop this framework, that is, outline the theoretical foundations of Coordination Dynamics. Our starting point, to that aim, is testing and elaborating a unifying mathematical model (the Excitator) that may capture the basic coordinative phenomena in the motor and perceptual domain in the context of questions and phenomena that are well rooted in the motor control literature, pertaining to (1) the identification of timing mechanisms; (2) divergence and convergence of (all combinations of) rhythmical and discrete movements (easily expandable to the perceptual domain); and (3) lag-one correlations in self-paced repetitive movements. |
|---|
| responsibles | Vercher, Fenouil |
|---|
| |
|