Adapting relative phase of bimanual isometric force coordination through scaling visual information intermittency

Lafe, Charley W.; Pacheco, Matheus M.; Newell, Karl M.

doi:10.1016/j.humov.2016.03.011

Cited by 11 publications

(10 citation statements)

References 40 publications

(33 reference statements)

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“…Note that the importance of visual feedback for stability of in-phase and out-of-phase coordination has also been demonstrated in isometric force production tasks (Lafe et al, 2016a,b). However, to our knowledge, our experiment is the first report on spontaneous phase desynchronization from both in-phase (Force task) and out-of-phase (Share task) regimes in symmetrical conditions and without changes in the action frequency.…”

Section: Discussionmentioning

confidence: 78%

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model

et al. 2017

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The study explored unintentional force changes elicited by removing visual feedback during cyclical, two-finger isometric force production tasks. Subjects performed two types of tasks at 1 Hz, paced by an auditory metronome. One – Force task – required cyclical changes in total force while maintaining the sharing, defined as relative contribution of a finger to total force. The other task – Share task – required cyclical changes in sharing while keeping total force unchanged. Each trial started under full visual feedback on both force and sharing; subsequently, feedback on the variable that was instructed to stay constant was frozen, and finally feedback on the other variable was also removed. In both tasks, turning off visual feedback on total force elicited a drop in the mid-point of the force cycle and an increase in the peak-to-peak force amplitude. Turning off visual feedback on sharing led to a drift of mean share toward 50:50 across both tasks. Without visual feedback there was consistent deviation of the two force time series from the in-phase pattern (typical of the Force task) and from the out-of-phase pattern (typical of the Share task). This finding is in contrast to most earlier studies that demonstrated only two stable patterns, in-phase and out-of-phase. We interpret the results as consequences of drifts of parameters in a dynamical system leading in particular to drifts in the referent finger coordinates toward their actual coordinates. The relative phase desynchronization is caused by the right-left differences in the hypothesized drift processes, consistent with the dynamic dominance hypothesis.

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Section: Discussionmentioning

confidence: 78%

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model

et al. 2017

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“…Here, a bimanual coordination factor (Bi-Co, see below) was defined to quantify the bimanual coordination control policy in this cooperative, non-rhythmic and non-cyclic task. Many studies have used the “relative phase” to investigate bimanual coordination ( Kelso, 1984 ; Rosenblum and Kurths, 1998 ; Sallagoïty et al, 2004 ; Lafe et al, 2016 ), i.e., the phase difference between two hands’ movements, which is an accepted optimum measurement for studying bimanual coordination in cyclic movements. However, our bimanual cooperative task required non-rhythmic and non-cyclic hand movements in different directions; thus, a measurement other than the relative phase was necessary to accordingly quantify the bimanual coordination.…”

Section: Methodsmentioning

confidence: 99%

Two Processes in Early Bimanual Motor Skill Learning

Doost

Xivry

Bihin

et al. 2017

Front. Hum. Neurosci.

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Most daily activities are bimanual and their efficient performance requires learning and retention of bimanual coordination. Despite in-depth knowledge of the various stages of motor skill learning in general, how new bimanual coordination control policies are established is still unclear. We designed a new cooperative bimanual task in which subjects had to move a cursor across a complex path (a circuit) as fast and as accurately as possible through coordinated bimanual movements. By looking at the transfer of the skill between different circuits and by looking at training with varying circuits, we identified two processes in early bimanual motor learning. Loss of performance due to the switch in circuit after 15 min of training amounted to 20%, which suggests that a significant portion of improvements in bimanual performance is specific to the used circuit (circuit-specific skill). In contrast, the loss of performance due to the switch in circuit was 5% after 4 min of training. This suggests that learning the new bimanual coordination control policy dominates early in the training and is independent of the used circuit. Finally, switching between two circuits throughout training did not affect the early stage of learning (i.e., the first few minutes), but did affect the later stage. Together, these results suggest that early bimanual motor skill learning includes two different processes. Learning the new bimanual coordination control policy predominates in the first minutes whereas circuit-specific skill improvements unfold later in parallel with further improvements in the bimanual coordination control policy.

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“…The second example comes from an actual throwing task to a target to illustrate how the search can be studied with many-degrees-of-freedom tasks (Pacheco and Newell, 2018c). The third example comes from a re-examination of the within-trial dynamics from a single trial in a bimanual isometric force tracking task (Lafe et al, 2016). Note that, although we provide in each case a single-subject example, the same analyses can be (and were) used to identify differences between individuals.…”

Section: Empirical Demonstrations Of Ssamentioning

confidence: 99%

“…The SSA approach can also provide information in other time-scales of practice (e.g., within-trials). In Lafe et al (2016), the task was to bimanually press two load cells each with an index finger to maintain a constant total force output while the frequency of concurrent feedback was manipulated. Figure 7A shows the data of total force over time through the different intermittent regimes of feedback.…”

Section: Empirical Demonstrations Of Ssamentioning

confidence: 99%

Search Strategies in the Perceptual-Motor Workspace and the Acquisition of Coordination, Control, and Skill

2019

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In this paper we re-visit and elaborate-on the theoretical framework of learning as searching within the perceptual-motor workspace for a solution to the task. The central focus is the nature of search strategies to locate and create stable equilibrium regions in the perceptual-motor workspace and how these strategies relate to the emergent movement forms in the acquisition of coordination, control, and skill. In the ecological theory of perception and action, the enhanced stability of performance occurs through the attunement of the perceptual systems to the task dynamics together with modifications of action as task and intrinsic dynamics cooperate and/or compete. Thus, through practice in this search process, individuals adapt to the pick-up of task relevant perceptual variables and change their movement form according to the stability of the performed action and its outcome in relation to the task demands. Contemporary experimental findings have revealed features of the search process given the interaction of individual intrinsic dynamics in the context of task requirements and principles that drive the change – e.g., exploitation of more tolerant task-space solutions and emergence of compensatory mechanisms. Finally, we outline how the search strategy framework relates to traditional learning-related phenomena: including the dynamical pathways of learning, learning curves, factors of learning, individuality, motor development, and sport and rehabilitation interventions.

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Adapting relative phase of bimanual isometric force coordination through scaling visual information intermittency

Cited by 11 publications

References 40 publications

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model

Two Processes in Early Bimanual Motor Skill Learning

Search Strategies in the Perceptual-Motor Workspace and the Acquisition of Coordination, Control, and Skill

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