Task dynamics define the contextual emergence of human corralling behaviors.

Social animals have the remarkable ability to organize into collectives to achieve goals unobtainable to individual members. Equally striking is the observation that despite differences in perceptual-motor capabilities, different animals often exhibit qualitatively similar collective states of organization and coordination. Such qualitative similarities can be seen in corralling behaviors involving the encirclement of prey that are observed, for example, during collaborative hunting amongst several apex predator species living in disparate environments.

Grasping Embodiment: Haptic Feedback for Artificial Limbs.

Upper-limb prostheses are subject to high rates of abandonment. Prosthesis abandonment is related to a reduced sense of embodiment, the sense of self-location, agency, and ownership that humans feel in relation to their bodies and body parts. If a prosthesis does not evoke a sense of embodiment, users are less likely to view them as useful and integrated with their bodies.

Feedback delays can enhance anticipatory synchronization in human-machine interaction.

Research investigating the dynamics of coupled physical systems has demonstrated that small feedback delays can allow a dynamic response system to anticipate chaotic behavior. This counterintuitive phenomenon, termed anticipatory synchronization, has been observed in coupled electrical circuits, laser semi-conductors, and artificial neurons. Recent research indicates that the same process might also support the ability of humans to anticipate the occurrence of chaotic behavior in other individuals.

Perception of another person's maximum reach-with-jump height from walking kinematics.

Humans can perceive affordances (possibilities for action) for themselves and others, including the maximum overhead height reachable by jumping (reach-with-jump height, RWJ). While observers can accurately perceive maximum RWJ for another person without previously seeing the person jump, estimates improve after viewing the person walk, suggesting there is structure in walking kinematics that is informative about the ability to produce vertical force for jumping. We used principal component analysis (PCA) to identify patterns in human walking kinematics that specify another person's maximum RWJ ability, and to determine whether athletes are more sensitive than non-athletes to these patterns.

Human social motor solutions for human-machine interaction in dynamical task contexts.

Multiagent activity is commonplace in everyday life and can improve the behavioral efficiency of task performance and learning. Thus, augmenting social contexts with the use of interactive virtual and robotic agents is of great interest across health, sport, and industry domains. However, the effectiveness of human-machine interaction (HMI) to effectively train humans for future social encounters depends on the ability of artificial agents to respond to human coactors in a natural, human-like manner.

Virtual auditory aperture passability.

Two experiments investigated (1) the ability of individuals to perceive the passability of apertures that are constructed using two virtual sounds sources and (2) the nature of the perceptual information that is used when determining passability in such a way. In the first experiment, participants judged whether they could successfully walk between two sound sources, heard through headphones, without turning their shoulders. We hypothesized that judgements would be accurate and driven by the detection of a proposed informational variable that relates head rotation, forward locomotion and aperture width.

Prospectively identified deficits in sagittal plane hip-ankle coordination in female athletes who sustain a second anterior cruciate ligament injury after anterior cruciate ligament reconstruction and return to sport.

Background: Athletes who return to sport after anterior cruciate ligament reconstruction are at increased risk of future ACL injury. Altered coordination of lower extremity motion may increase this risk. The purpose of this study was to prospectively determine if altered lower extremity coordination patterns exist in athletes who go on to sustain a 2nd anterior cruciate ligament injury.

Functional Task Constraints Foster Enhanced Postural Control in Children With Cerebral Palsy.

Background: Postural instability is a classical characteristic of cerebral palsy (CP), but it has not been examined during functional play activity. Recent work has demonstrated that when motor tasks are made functionally more relevant, performance improves, even in children with movement pathology. It is possible that in a disease state, the underlying control mechanisms that are associated with healthy physiology must be elicited.

Harmony from chaos? Perceptual-motor delays enhance behavioral anticipation in social interaction.

Effective interpersonal coordination is fundamental to robust social interaction, and the ability to anticipate a coactor's behavior is essential for achieving this coordination. However, coordination research has focused on the behavioral synchrony that occurs between the simple periodic movements of coactors and, thus, little is known about the anticipation that occurs during complex, everyday interaction. Research on the dynamics of coupled neurons, human motor control, electrical circuits, and laser semiconductors universally demonstrates that small temporal feedback delays are necessary for the anticipation of chaotic events.

Movement constraints on interpersonal coordination and communication.

The present study investigated how constraining movement affects interpersonal coordination and joint cognitive performance. Pairs of participants worked cooperatively to solve picture-puzzle tasks in which they conversed to identify differences between pictures in 3 degree-of-constraint conditions: both participants were free to move their hands (free-free; FF); both participants' hands were restrained (restrained-restrained; RR); and the hands of 1 participant were free while the hands of the other participant were restrained (free-restrained; FR). Eye tracking data were collected, and movement was measured at the waist, hand, and head.

Essential kinematic information, athletic experience, and affordance perception for others.

The present study investigated the role of different types of movement in affordance perception, as well as the influence of sports experience. Perception of another actor's maximum vertical jumping height and horizontal long-jumping distance was evaluated for basketball players, soccer players, and nonplayer controls after viewing point-light representations of the actors' movements. Perceptual reports were more accurate after jumping-related movements (walking and squatting) were viewed than after nonrelated movements (standing and twisting).

Lower-limb proprioceptive awareness in professional ballet dancers.

Enhanced proprioceptive feedback strengthens synergistic muscle groups and stabilizes the coordination of limbs, thus contributing to the movement efficiency of ballet dancers. The present study compared lower-limb proprioceptive awareness in professional ballet dancers to matched controls who had no dance training. Two assessment methods were used to test the hypothesis that ballet dancers would demonstrate increased proprioceptive awareness in the ankle, knee, and hip: 1.

Development of coordination in time estimation.

How to best characterize cognitive development? The claim put forward in this article is that development is the improvement of a kind of coordination among a variety of factors. To determine the development of coordination in a cognitive task, children between 4 and 12 years of age and adults participated in a time estimation task: They had to press a button every time they thought a short time interval had passed. The resulting data series of estimated time intervals was then subjected to a set of fractal analyses to quantify coordination in terms of its degree of "rigidity" (very highly integrated) vs.

Multimodally specified energy expenditure and action-based distance judgments.

Previous research has demonstrated that perceived self-motion can be manipulated by the relation between optic flow rate and walking rate. Other studies have revealed that verbal reports of perceived distance are influenced by the energy that would be expended to traverse the distance in question. In an effort to integrate these findings, we investigated how action-based distance judgments are influenced by multimodally specified energy expenditure (MSEE)--the metabolic cost associated with traversing an optically specified distance--using a virtual-reality treadmill environment.

Inter-segmental postural coordination measures differentiate athletes with ACL reconstruction from uninjured athletes.

Athletes who sustain non-contact anterior cruciate ligament (ACL) injuries and undergo surgical reconstruction exhibit deficits in sensorimotor control, which often impairs lower-limb movement coordination. The purpose of this experiment was to measure the influence of sensorimotor deficits on the ankle-hip coordination of a postural coordination task in athletes following ACL reconstruction. Twenty-two female athletes who were cleared to return to sports participation following ACL reconstruction and 22 uninjured female athletes performed a unilateral dynamic postural rhythmic coordination task at two movement frequencies (0.

Felt heaviness is used to perceive the affordance for throwing but rotational inertia does not affect either.

Bingham et al. discovered a perceptible affordance property, composed of a relation between object weight and size, used to select optimal objects for long-distance throwing. Subsequent research confirmed this finding, but disconfirmed a hypothesis formulated by Bingham et al.

Interpersonal and intrapersonal coordinative modes for joint and single task performance.

In recent years, research in the field of social interactions has focused on the exploration of the coordinative structures that substantiate joint task performance. The current project explores whether interpersonal coordination during joint task performance gives rise to a joint coordinative structure across individuals, and whether such coordinative structures are affected by task demands. Principal component analysis (PCA) is used to identify relevant interpersonal and intrapersonal coordinative modes for the single and joint performance of a supra-postural task, which varied along its precision and role demands.

Learning from the body about the mind.

In some areas of cognitive science we are confronted with ultrafast cognition, exquisite context sensitivity, and scale-free variation in measured cognitive activities. To move forward, we suggest a need to embrace this complexity, equipping cognitive science with tools and concepts used in the study of complex dynamical systems. The science of movement coordination has benefited already from this change, successfully circumventing analogous paradoxes by treating human activities as phenomena of self-organization.

Effect of precision aiming on respiration and the postural-respiratory synergy.

Precision manual tasks require a stable postural background which might be facilitated by respiratory modulations. We investigated the influence of performing a manual precision aiming task on respiratory rate and dynamics, and the coherence between respiration and center of pressure (COP) fluctuations (i.e.

Interpersonal synergies.

We present the perspective that interpersonal movement coordination results from establishing interpersonal synergies. Interpersonal synergies are higher-order control systems formed by coupling movement system degrees of freedom of two (or more) actors. Characteristic features of synergies identified in studies of intrapersonal coordination - dimensional compression and reciprocal compensation - are revealed in studies of interpersonal coordination that applied the uncontrolled manifold approach and principal component analysis to interpersonal movement tasks.

Multi-segmental postural coordination in professional ballet dancers.

Ballet dancers have heightened balance skills, but previous studies that compared dancers to non-dancers have not quantified patterns of multi-joint postural coordination. This study utilized a visual tracking task that required professional ballet dancers and untrained control participants to sway with the fore-aft motion of a target while standing on one leg, at target frequencies of 0.2 and 0.

Joint action in a cooperative precision task: nested processes of intrapersonal and interpersonal coordination.

The authors determined the effects of changes in task demands on interpersonal and intrapersonal coordination. Participants performed a joint task in which one participant held a stick to which a circle was attached at the top (holding role), while the other held a pointer through the circle without touching its borders (pointing role). Experiment 1 investigated whether interpersonal and intrapersonal coordination varied depending on task difficulty.

The influence of athletic experience and kinematic information on skill-relevant affordance perception.

Humans can perceive affordances both for themselves and for others, and affordance perception is a function of perceptual-motor experience involved in playing a sport. Two experiments investigated the enhanced affordance perception of athletes. In Experiment 1, basketball players and nonbasketball players provided perceptual reports for sports-relevant (maximum standing-reach and reach-with-jump heights) and non-sports-relevant (maximum sitting height) affordances for self and other.

Perceiving action boundaries: learning effects in perceiving maximum jumping-reach affordances.

Coordinating with another person requires that one can perceive what the other is capable of doing. This ability often benefits from opportunities to practice and learn. Two experiments were conducted in which we investigated perceptual learning in the context of perceiving the maximum height to which an actor could jump to reach an object.