Intentional Switching Between Bimanual Coordination Patterns

Previous theoretical and empirical work indicates that intentional changes in a bimanual coordination pattern depends on the stability of the bimanual coordination pattern (Kelso, Schotz, & Schöner, 1988; Scholz & Kelso, 1990). The present experiments retest this notion when online Lissajous displays are provided. Switching to and from in-phase and antiphase and to and from 90° and 270° were tested in Experiment 1. Participants were able to very effectively produce the 180°, 90°, and 270° coordination patterns although performance of the in-phase coordination task was even more stable. The data indicated that switching to in-phase from antiphase was more rapid than vice versa and that switching times between 90° to 270° were similar. Experiment 2 investigated switching between 1:2 and 2:1 bimanual coordination patterns. The results indicated that switching time was similar between the 2:1 and 1:2 coordination tasks and that increases in stability over practice resulted in additional decreases in switching times. This provides additional evidence that the attractor landscape is fundamentally different dependent on the type of information provided the performer. What remains to be done is to reconcile these results with the various theories/perspectives currently used to describe and explain bimanual coordination.     

Probing Representations of Gymnastics Movements: A Visual Priming Study

In this study, we designed a visual short‐term priming paradigm to investigate the mechanisms underlying the priming of movements and to probe movement representations in motor experts and matched controls. We employed static visual stimuli that implied or not human whole‐body movements, that is, gymnastics movements and static positions. Twelve elite female gymnasts and twelve matched controls performed a speeded two‐choice response time task. The participants were presented with congruent and incongruent prime‐target pairs and had to decide whether the target stimulus represented a gymnastics movement or a static position. First, a visual priming effect was observed in the two groups. Second, a stimulus–response rote association could not easily account for our results. Novel primes never presented as targets could also prime the targets. Third, by manipulating three levels of prime‐target relations in moving congruent pairs, we demonstrated that the more similar prime‐target pairs, the greater the facilitation in target. Lastly, gymnastics motor expertise impacted on priming effects.     

Postural coordination patterns as a function of dynamics of the support surface

The present study investigated the compensatory postural coordination patterns that emerge in the face of dynamic changes in the surface of support. Adult subjects stood on a moving platform that was sinusoidally translated in the anterior-posterior direction. The frequency and amplitude of the support surface translation were manipulated over a wide range of parameter values. The results revealed that as the frequency of platform motion increased, the postural system systematically exploited the available joint-space degrees of freedom and generated four distinct postural coordination modes (a rigid mode --> ankle mode --> ankle-hip mode --> ankle-hip-knee mode). It appears that upright standing posture has a small set of coordination patterns that are particular to the dynamics of the surface of support.     

The dynamics of coordinated reaching and grasping: Scanning prehension properly

Prehension is the act of coordinated reaching and grasping. S.A. Wallace, E. Stevenson, A. Spear, D.L. Weeks [Hum. Movement Sci. 13 (1994) 255–289] proposed to assess the stability of this coordination by scanning the dynamics of prehension. The scanning method proposed by these authors prompted participants to position their peak hand aperture at different locations along the trajectory. Comparing the actual performance with the required performance, Wallace and colleagues concluded that there was a single stable pattern of coordination, albeit different for each individual. Here, we show that the method developed by Wallace et al. (1994, loc. cit.), and later used by C. Button, S. Bennett, K. Davids [Hum. Movement Sci. 17 (1998) 801–820] was flawed. We propose two potential fixes to the method and report a replication of the original experiment. Interpretation of the data with a corrected scanning technique showed that the method does not seem to be able to result in an unambiguous and precise assessment of the locus of stability.     

The rhythm of rapport: Interpersonal synchrony and social perception

The temporal coordination of behavior during dyadic interactions is a foundation for effective social exchange with synchronized actions enhancing perceptions of rapport and interpersonal connectedness. What has yet to be established, however, are the precise characteristics of behavioral coordination that give rise to such effects. Informed by a dynamical systems approach, the current investigation considered whether judgments of rapport are influenced by the mode of interpersonal synchrony. In two experiments, participants rated the degree of rapport manifest by a simulated pair of walkers exhibiting various configurations of synchronized strides. The results revealed that the highest levels of rapport were associated with the most stable forms of interpersonal coordination (i.e., in-phase and anti-phase synchrony), regardless of whether coordination between the walkers was conveyed via the presentation of visual (Expt. 1a) or auditory (Expt. 1b) cues. These findings underscore the importance of interpersonal coordination to core aspects of social perception.     

A kinematic approach to the conceptual representations of this and that

The Italian demonstrative pronouns questo/a (‘this_[mas/fem]’) and quello/a (‘that_[mas/fem]’) implicitly convey information about objects’ distance with respect to the speaker. Our study investigated the referents of questo/a (‘this_[mas/fem]’) and quello/a (‘that_[mas/fem]’) by analysing their influence on reach-to-grasp actions towards objects located near to (12 cm) or far from (30 cm) the participant. Upon acoustic instruction containing one or the other pronoun, participants had to reach for and grasp a target object. Results showed an effect of pronoun on movement planning. When the object was in the far position, reaction times were faster for the congruent pronoun quello/a, whereas when it was in the near position they were faster for the congruent pronoun questo/a. Interactions between implied and real target distance suggest that the conceptual spaces of questo/a and quello/a do not map onto a strict distinction between peripersonal and extrapersonal space.     

The influence of asymmetric force requirements on a multi-frequency bimanual coordination task

An experiment was designed to determine the impact of the force requirements on the production of bimanual 1:2 coordination patterns requiring the same (symmetric) or different (asymmetric) forces when Lissajous displays and goal templates are provided. The Lissajous displays have been shown to minimize the influence of attentional and perceptual constraints allowing constraints related to neural crosstalk to be more clearly observed. Participants (N = 20) were randomly assigned to a force condition in which the left or right limb was required to produce more force than the contralateral limb. In each condition participants were required to rhythmically coordinate the pattern of isometric forces in a 1:2 coordination pattern. Participant performed 13 practice trials and 1 test trial per force level. The results indicated that participants were able to effectively coordinate the 1:2 multi-frequency goal patterns under both symmetric and asymmetric force requirements. However, consistent distortions in the force and force velocity time series were observed for one limb that appeared to be associated with the production of force in the contralateral limb. Distortions in the force produced by the left limb occurred regardless of the force requirements of the task (symmetric, asymmetric) or whether the left or right limb had to produce more force than the contralateral limb. However, distinct distortions in the right limb occurred only when the left limb was required to produce 5 times more force than the right limb. These results are consistent with the notion that neural crosstalk can influence both limbs, but may manifest differently for each limb depending on the force requirements of the task.     

Collaborative communication efficiency is linked to relationship satisfaction in dating couples

The speed, or efficiency, in which people communicate is linked to positive interpersonal outcomes. However, no studies of communication efficiency have examined romantic partners, making it unclear whether efficient communication is linked to relationship satisfaction above and beyond previously identified communication skills (e.g., problem‐solving). We recruited dating couples (N = 56) to attend a laboratory session to complete survey measures and a collaborative communication task. Multilevel models demonstrated that both task efficiency (β = ?.36, p = .04) and self‐reported problem‐solving communication skills (β = .28, p = .002) were associated with relationship satisfaction. Results suggest that communication task efficiency can be meaningfully applied to the study of romantic relationships and couple communication skills.     

The symbol in the body: the un-doing of a dissociation through Embodied Active Imagination in Jungian analysis

Jung understood dissociation as a natural state of the psyche, capable of turning defensive through development. Based on this premise, and its conception on the equivalence between psyche and matter, the present work describes the un-doing of a dissociation expressed through a chronic enterocolitis disorder. When the symbol remains closer to the body and its most instinctive manifestations, we need to descend to that level in order to let the vertical axis connection be gradually restored through the therapeutic relationship – the horizontal axis. In other words, this un-doing requires that patient and analyst follow the unconscious path proposed by symbolic expressions that gradually emerge through the patient’s body and active imagination. Movement is our most primitive and fundamental experience. Many authors (Stern, Panksepp, Gallese) have agreed that, in addition to being first in terms of development, movement continues to have primacy over any other experience throughout life. This means that emotions, bodily concepts and, later, speech, evolve from a somatic basis. In the light of such neuroscientific findings, Jung’s vision of the correspondence of psyche and matter will be revisited in order to portray how the analytic bond provides a context for the re-establishment of the linking/creative function of the archetype, and allows the restoring of the ego-Self axis connection by including non-verbal approaches, such as body-based active imagination, also known as Authentic Movement. Authentic Movement is an amplification of Jung’s active imagination method that enables a dialogue between the ego and the diverse configurations of the unconscious. When such dialogue is grounded in the body, there is an easier access to the affective dimension stored in implicit memory. That which was relived through the body can gradually be remembered, and affects hitherto rejected, find other symbolic ways of being expressed and contained in the analytic vas.