Affordances shape pass kick behavior in association football : effects of distance and social context

A prerequisite for accurate passing in association football is that a player perceives the affordances, that is, the opportunities for action, of a given situation. The present study examined how affordances shape passing in association football by comparing the performance of pass-kicks in two task conditions. Participants performed pass-kicks into either a stationary goal or to a teammate over a range of distances. The following passing action variables were measured: passing accuracy, pass preparation time, pass-kick technique, passing height, and passing velocity. Participants mainly used inside-foot pass-kicks with little to no height over the entire range of distances when the task was to perform pass-kicks into a stationary goal. However, when the task was to kick to a teammate, participants used inside-foot passkicks with little to no height for short distance passes and switched to relatively more instep-foot pass-kicks with more height for longer distances. Overall, pass preparation time increased with increasing distance, while participants took less time to prepare for pass-kicks to a moving teammate. The paper outlines these results in terms of the perception of (social) affordances for passing in football

A Re-Appraisal of the Effect of Amplitude on the Stability of Interlimb Coordination Based on Tightened Normalization Procedures

The stability of rhythmic interlimb coordination is governed by the coupling between limb movements. While it is amply documented how coordinative performance depends on movement frequency, theoretical considerations and recent empirical findings suggest that interlimb coupling (and hence coordinative stability) is actually mediated more by movement amplitude. Here, we present the results of a reanalysis of the data of Post, Peper, and Beek (2000), which were collected in an experiment aimed at teasing apart the effects of frequency and amplitude on coordinative stability of both steady-state and perturbed in-phase and antiphase interlimb coordination. The dataset in question was selected because we found indications that the according results were prone to artifacts, which may have obscured the potential effects of amplitude on the post-perturbation stability of interlimb coordination. We therefore redid the same analysis based on movement signals that were normalized each half-cycle for variations in oscillation center and movement frequency. With this refined analysis we found that (1) stability of both steady-state and perturbed coordination indeed seemed to depend more on amplitude than on movement frequency per se, and that (2) whereas steady-state antiphase coordination became less stable with increasing frequency for prescribed amplitudes, in-phase coordination became more stable at higher frequencies. Such effects may have been obscured in previous studies due to (1) unnoticed changes in performed amplitudes, and/or (2) artifacts related to inappropriate data normalization. The results of the present reanalysis therefore give cause for reconsidering the relation between the frequency, amplitude, and stability of interlimb coordination

Rowing Crew Coordination Dynamics at Increasing Stroke Rates

In rowing, perfect synchronisation is important for optimal performance of a crew. Remarkably, a recent study on ergometers demonstrated that antiphase crew coordination might be mechanically more efficient by reducing the power lost to within-cycle velocity fluctuations of the boat. However, coupled oscillator dynamics predict the stability of the coordination to decrease with increasing stroke rate, which in case of antiphase may eventually yield breakdowns to in-phase. Therefore, this study examined the effects of increasing stroke rate on in- and antiphase crew coordination in rowing dyads. Eleven experienced dyads rowed on two mechanically coupled ergometers on slides, which allowed the ergometer system to move back and forth as one 'boat'. The dyads performed a ramp trial in both in- and antiphase pattern, in which stroke rates gradually increased from 30 strokes per minute (spm) to as fast as possible in steps of 2 spm. Kinematics of rowers, handles and ergometers were captured. Two dyads showed a breakdown of antiphase into in-phase coordination at the first stroke rate of the ramp trial. The other nine dyads reached between 34-42 spm in antiphase but achieved higher rates in in-phase. As expected, the coordinative accuracy in antiphase was worse than in in-phase crew coordination, while, somewhat surprisingly, the coordinative variability did not differ between the patterns. Whereas crew coordination did not substantially deteriorate with increasing stroke rate, stroke rate did affect the velocity fluctuations of the ergometers: fluctuations were clearly larger in the in-phase pattern than in the antiphase pattern, and this difference significantly increased with stroke rate. Together, these results suggest that although antiphase rowing is less stable (i.e., less resistant to perturbation), potential on-water benefits of antiphase over in-phase rowing may actually increase with stroke rate

Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination.

Peters (J Motor Behav 21:151-155, 1989; Interlimb coordination: neural, dynamical and cognitive constraints, Academic, Orlando, pp 595-615, 1994) suggested that expressions of handedness in bimanual coordination may be reflections of an inherent attentional bias. Indeed, previous results indicated that focusing attention on one of the limbs affected the relative phasing between the limbs in a manner comparable to the effects of hand dominance. The present study extended the comparison between the effects of attentional focus and handedness by testing their impact on the interactions between the limbs. Both left-handed and right-handed participants performed rhythmic bimanual coordination tasks (in-phase and antiphase coordination), while directing attention to either limb. Using brief mechanical perturbations, the degree to which the limbs were influenced by each other was determined. The results revealed that the non-dominant limb was more strongly affected by the dominant limb than vice versa and that, in line with Peters' proposition, this handedness-related asymmetry in coupling strength was reduced when attention was focused on the non-dominant limb, thereby highlighting the potential relation between inherent (handedness-related) asymmetries and voluntary attentional asymmetries. In contrast to previous findings, the (commonly observed) phase lead of the dominant limb was attenuated (rather than accrued) when attention was focused on this limb. This unexpected result was explained in terms of the observed attention-related difference in amplitude between the limbs. © 2006 Springer-Verlag

Anisotropy and Antagonism in the Coupling of Two Oscillators: Concepts and Applications for Between-Person Coordination

Coupled oscillators provide a pertinent model approach to study between-person movement dynamics. While ample literature in this respect has considered the influence of external/environmental constraints and/or effects of a difference between the two agents' individual component dynamics (e.g., mismatch in natural frequency), recent studies also started to more directly consider the interaction per-se. The current perspective paper sets forth that while movement coordination dynamics has mainly been studied alongside a model in which the coupling is considered isotropic (i.e., symmetrical: both oscillators coupled to same degree) or strictly unidirectional (e.g., for moving to a given external rhythm), between-agent coupling involves a natural anisotropy: components influence each other bidirectionally to different degrees. Furthermore, recent research from different areas has considered so-called antagonistic or "competitive" coupling, which refers to the idea that one component is positively coupled to the other (attractive interaction), while the coupling in the other direction is negative (repulsive interaction). Although the latter would be rather tricky to address in within-person coordination, it does have strong applications and implications for between-person dynamics, for instance in the study of competitive interactions in sports situations (e.g., attacker-defender) and conflicting social (movement) interactions. The paper concludes by offering a conceptual framework and perspectives for future studies on the dynamic anisotropic nature of the interaction in between-person contexts

Asymmetric interpersonal coupling in a cyclic sports-related movement task

In interactive sports, teammates and/or opponents mutually tune their behavior. Expert performance thus implies certain interactive abilities, which critically depend on perceptual coupling. To illustrate this assertion, we examined the coordination dynamics with asymmetric interaction of dyads performing a sports-related cyclical movement task. In pairs, basketball players performed lateral defensive slides in in-phase, until a cue prompted them to switch to antiphase coordination. We assessed how these switches were mediated by phase adaptations of each agent under bidirectional (i.e., agents facing one another) and unidirectional (i.e., one agent facing the back of the other) visual interaction conditions. This imposed asymmetry in visual coupling exemplified an imbalance in the interaction (or 'interact-ability') between two agents. The results concurred the asymmetric coupling: during the switch the agent facing the other adapted his phasing more than the other agent. Furthermore, also in the bidirectional condition the coupling revealed dyad-intrinsic asymmetries (e.g., related to implicit follower-leader strategies). Together, this illustrates that interpersonal coordination is characterized by asymmetric coupling between the agents, and highlights how mutual perception of pertinent information mediates interpersonal coordination. This study offered a first step towards analyzing interpersonal coordination dynamics in relation to 'interact-ability'. (C) 2014 Elsevier B.V. All rights reserved

Inviting affordances and agency

Recently several authors have suggested that affordances are not mere possibilities for action but can also invite behavior. This reconceptualization of affordances asks for a reconsideratioh of the ecological approach to agency. After a portrayal of the role of agency in ecological psychology, we draw upon phenomenology to reveal what it means for an agent to be invited by affordances. We sketch a dynamical model of the animal-environment relationship that aims to do justice to this analysis. In the model, agency is conceptualized as the capacity to modulate the coupling strength with the environment the agent can influence to what extent he or she is influenced by the different invitations. This account of agency keeps us far from the Cartesian idea that the agent imposes behavior. Indeed, by modulating the coupling strength, the agent simply alters the dynamics of the animal-environment interactions and thus the behavior that emerges. (C) 2017 Elsevier Ltd. All rights reserved