A leader–follower relationship in joint action on a discrete force production task

The concept of hierarchical motor control has been viewed as a means of progressively decreasing the number of variables manipulated by each higher control level. We tested the hypothesis that turning an individual bimanual force-production task into a joint (two-participant) force-production task would lead to positive correlation between forces produced by the two hands of the individual participant (symmetric strategy) to enable negative correlation between forces produced by two participants (complementary strategy). The present study consisted of individual and joint tasks that involved both unimanual and bimanual conditions. In the joint task, 10 pairs of participants produced periodic isometric forces, such that the sum of forces that they produced matched a target force cycling between 5% and 10% of maximum voluntary contraction at 1 Hz. In the individual task, individuals attempted to match the same target force. In the joint bimanual condition, the two hands of each participant adopted a symmetric strategy of force, whereas the two participants adopted a complementary strategy of force, highlighting that the bimanual action behaved as a low level of a hierarchy, whereas the joint action behaved as an upper level. The complementary force production was greater interpersonally than intrapersonally. However, whereas the coherence was highest at 1 Hz in all conditions, the frequency synchrony was stronger intrapersonally than interpersonally. Moreover, whereas the bimanual action exhibited a smaller error and variability of force than the unimanual action, the joint action exhibited a less-variable interval and force than the individual action.

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The Effect of Frequency of Kinetic Feedback on Learning an Isometric Force Production Task in Nondisabled Subjects

Physical Therapy ◽

10.1093/ptj/73.2.79 ◽

1993 ◽

Vol 73 (2) ◽

pp. 79-87 ◽

Cited By ~ 76

Author(s):

Darl W Vander Linden ◽

James H Cauraugh ◽

Tracy A Greene

Keyword(s):

Isometric Force ◽

Force Production ◽

Production Task ◽

Isometric Force Production ◽

Force Production Task

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Mental Fatigue Reduces the Benefits of Self-Controlled Feedback on Learning a Force Production Task

Perceptual and Motor Skills ◽

10.1177/00315125211037306 ◽

2021 ◽

pp. 003151252110373

Author(s):

Milad Khojasteh Moghani ◽

Rasool Zeidabadi ◽

Mohammad Reza Shahabi Kaseb ◽

Iman Bahreini Borujeni

Keyword(s):

Repeated Measures ◽

Transfer Test ◽

Force Production ◽

Mental Fatigue ◽

The Self ◽

Acquisition Phase ◽

Production Task ◽

Significant Group ◽

The Impact ◽

Force Production Task

This study investigated the impact of mental fatigue and self-controlled versus yoked feedback on learning a force production task. We randomly assigned 44 non-athlete male students (Mage = 21.4, SD = 1.4 years) to four groups; (a) MF&SCF = mental fatigue & self-controlled feedback, (b) MF&Y = mental fatigue & yoked, (c) NMF&SCF = no mental fatigue & self-controlled feedback, and (d) NMF&Y = no mental fatigue & yoked). SCF group participants were provided feedback whenever they requested it, while YK group participants received feedback according to a schedule created by their SCF counterparts. To induce mental fatigue, participants performed a Stroop color-word task for one hour. During the acquisition (practice) phase, participants were asked to produce a given percentage of their maximum force (20%) in 12 blocks of six trials. We recorded the participants’ absolute error at the end of the acquisition phase, the immediate retention test, the first transfer test, and the second transfer test (after 24 hours and without any further mental fatigue). The acquisition phase data were analyzed in a 2 (feedback) × 2 (mental fatigue) × 12 (block) ANOVA with repeated measures on the last factor, while the retention and transfer data were analyzed in 2 (feedback) × 2 (mental fatigue) ANOVAs. We found that all four groups made significant progress during practice ( p < .001), but there were no significant group differences during this phase ( p>.05). There was a significant interaction effect of self-controlled feedback and mental fatigue at retention ( p = .018) and transfer testing ( p < .001). In the mental fatigue condition, participants in the self-controlled group had poorer learning compared to participants in the yoked group; but when not mentally fatigued, participants in the self-controlled group had better learning than those in the yoked group. These findings suggest that mental fatigue reduces typical advantages of self-controlled feedback in motor learning.

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