Functional Interdependence in Coupled Dissipative Structures: Physical Foundations of Biological Coordination

Coordination within and between organisms is one of the most complex abilities of living systems, requiring the concerted regulation of many physiological constituents, and this complexity can be particularly difficult to explain by appealing to physics. A valuable framework for understanding biological coordination is the coordinative structure, a self-organized assembly of physiological elements that collectively performs a specific function. Coordinative structures are characterized by three properties: (1) multiple coupled components, (2) soft-assembly, and (3) functional organization. Coordinative structures have been hypothesized to be specific instantiations of dissipative structures, non-equilibrium, self-organized, physical systems exhibiting complex pattern formation in structure and behaviors. We pursued this hypothesis by testing for these three properties of coordinative structures in an electrically-driven dissipative structure. Our system demonstrates dynamic reorganization in response to functional perturbation, a behavior of coordinative structures called reciprocal compensation. Reciprocal compensation is corroborated by a dynamical systems model of the underlying physics. This coordinated activity of the system appears to derive from the system’s intrinsic end-directed behavior to maximize the rate of entropy production. The paper includes three primary components: (1) empirical data on emergent coordinated phenomena in a physical system, (2) computational simulations of this physical system, and (3) theoretical evaluation of the empirical and simulated results in the context of physics and the life sciences. This study reveals similarities between an electrically-driven dissipative structure that exhibits end-directed behavior and the goal-oriented behaviors of more complex living systems.

Gymnastics Experience Enhances the Development of Bipedal-Stance Multi-Segmental Coordination and Control During Proprioceptive Reweighting

Performance and control of upright bipedal posture requires a constant and dynamic integration of relative contributions of different sensory inputs (i. e., sensory reweighting) to enable effective adaptations as individuals face environmental changes and perturbations. Children with gymnastic experience showed balance performance closer to that of adults during and after proprioceptive alteration than children without gymnastic experience when their center of pressure (COP) was analyzed. However, a particular COP sway can be achieved through performing and coordinating different postural movements. The aim of this study was to assess how children and adults of different gymnastic experience perform and control postural movements while they have to adjust balance during and after bilateral tendon vibration. All participants were equipped with spherical markers attached to their skin and two vibrators strapped over the Achilles tendons. Bipedal stance was performed in three 45-s trials in two visual conditions (eyes open, EO, and eyes closed, EC) ordered randomly in which vibration lasted 10 s. Posture movements were analyzed by a principal component analysis (PCA) calculated on normalized and weighted markers coordinates. The relative standard deviation of each principal movement component (principal position, PP-rSTD) quantified its contribution to the whole postural movements, i.e., quantified the coordinative structure. The first (principal velocities, PV-rSTD) and second (principal accelerations, PA-rSTD) time-derivatives characterized the rate-dependent sensory information associated with and the neuromuscular control of the postural movements, respectively. Children without gymnastic experience showed a different postural coordinative structure and different sensory-motor control characteristics. They used less ankle movements in the anterior-posterior direction but increased ankle movements in medio-lateral direction, presented larger hip and trunk velocities, and exhibited more hip actions. Gymnastic experience during childhood seemed to benefit the development of proprioceptive reweighting processes in children, leading to a more mature form of coordinating and controlling posture similarly to adults.

Adolescent Awkwardness: Alterations in Temporal Control Characteristics of Posture with Maturation and the Relation to Movement Exploration

A phenomenon called adolescent awkwardness is believed to alter motor control, but underlying mechanisms remain largely unclear. Since adolescents undergo neurological and anthropometrical changes during this developmental phase, we hypothesized that adolescents control their movements less tightly and use a different coordinative structure compared to adults. Moreover, we tested if emerging differences were driven by body height alterations between age groups. Using 39 reflective markers, postural movements during tandem stance with eyes open and eyes closed of 12 adolescents (height 168.1 ± 8.8 cm) and 14 adults were measured, in which 9 adults were smaller or equal than 180 cm (177.9 ± 3.0 cm) and 5 taller or equal than 190 cm (192.0 ± 2.5 cm). A principal component analysis (PCA) was used to extract the first nine principal movement components (PMk). The contribution of each PMk to the overall balancing movement was determined according to their relative variance share (rVARk) and tightness of motor control was examined using the number of times that the acceleration of each PMk changed direction (Nk). Results in rVARk did not show significant differences in coordinative structure between adolescents and adults, but Nk revealed that adolescents seem to control their movements less tightly in higher-order PMk, arguably due to slower processing times and missing automatization of postural control or potential increases in exploration. Body height was found to not cause motor control differences between age groups.

Leg Dominance Effects on Postural Control When Performing Challenging Balance Exercises

Leg dominance reflects the preferential use of one leg over another and is typically attributed to asymmetries in the neural circuitry. Detecting leg dominance effects on motor behavior, particularly during balancing exercises, has proven difficult. The current study applied a principal component analysis (PCA) on kinematic data, to assess bilateral asymmetry on the coordinative structure (hypothesis H1) or on the control characteristics of specific movement components (hypothesis H2). Marker-based motion tracking was performed on 26 healthy adults (aged 25.3 ± 4.1 years), who stood unipedally on a multiaxial unstable board, in a randomized order, on their dominant and non-dominant leg. Leg dominance was defined as the kicking leg. PCA was performed to determine patterns of correlated segment movements (“principal movements” PMks). The control of each PMk was characterized by assessing its acceleration (second-time derivative). Results were inconclusive regarding a leg-dominance effect on the coordinative structure of balancing movements (H1 inconclusive); however, different control (p = 0.005) was observed in PM3, representing a diagonal plane movement component (H2 was supported). These findings supported that leg dominance effects should be considered when assessing or training lower-limb neuromuscular control and suggest that specific attention should be given to diagonal plane movements.

The ellipsis of grammatical functions in coordinative structure of Japanese language

The discussion in this paper is focused on the ellipsis of grammatical functions in Japanese covering that of the function of grammatical of coordinative structure. The data analyzed in this paper were taken from Japanese corpus data. The concept of ellipsis was taken from Quirk et al., (1985), Makino & Tsutsui, (1994), and Verhaar (1981). The ellipsis from Quirk et al (1985) was applied the concept of recoverability from the grammatical point of view: (1) textual recoverability, (2) situational recoverability, and (3) structural recoverability. The qualitative and synchronic descriptive method was employed in this study. A qualitatively descriptive method was employed to explain and describe the coordinative sentence, whereas the synchronic approach was used to cover the current language phenomena. The findings show that in the coordinative structure, ellipsis of the function of grammatical subject, ellipsis the function of predicate and ellipsis of the function of object took place. Ellipsis of the function of grammatical in the coordinative structure can be anaphoric or cataphoric. It is called anaphoric because the ellipsis takes place rightward, the controlling constituents are located in the first clauses and the controlled constituents are located in the second clause. It is called cataphoric because the controlling constituents are located in the second clauses and the controlled constituents are located in the first clauses.

Network Approach to Inducing Coordinative Structures of Skillful Movements

Even though coordination is the key to explaining skillful movement, as advocated by Bernstein, analyzing the coordinative structure of body parts remains yet to be fully addressed. Pattern matching applied to analyzing skillful movement cannot describe the coordinative structure. A correlation network is useful for identifying the most influential factor in the web of correlations among factors. The correlation network is thus thought to be effective in analyzing coordinative structures because it enables us to identify the body partmost influential in skillful movement. As an example of skillful movement, we investigated traditional Japanese Heike-daiko drumming to see if we could describe the coordinative structure through this approach. We created correlation networks among body parts involved in playing the Heike-daiko. We asked a Heike-daiko player to play a rhythmic pattern typical of traditional drumming and collected data on movement using a motion capture device. We split the performance sequence into 10 sections, each exhibiting a unique characteristic of the player. It was difficult for onlookers to distinguish these 10 patterns because differences were too subtle to recognize visually. By applying our method to data, we found overlaps among the 10 sections in that the same set of body parts tends to form a network through the sequence. Results suggest that movement similarities and differences can be captured by comparing correlation networks among body parts. We also found two classes of coordinative structure, one reflecting our anatomical structure and the other quite different from it. We found that second class classifies skillful movement.