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Recruitment of Degrees of Freedom based on Multimodal Information about Interlimb Coordination

Bachus, Laura E.
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406819390

Abstract Details

2014, PhD, University of Cincinnati, Arts and Sciences: Psychology.
The present experiments were designed to determine whether degree of freedom (df) recruitment serves to stabilize coordination, whether there is a tradeoff between df recruitment and coordination stability, and to further explore the role of vision and biomechanics on interlimb coordination. Participants moved their hands in the transverse plane, which caused corresponding motion of a virtual marker in the coronal plane. The participants’ goal was to trace symmetric or asymmetric elliptical shapes on a projection screen with the virtual marker. Experiment 1 decoupled biomechanical symmetry from visual symmetry by implementing a translational gain. Both visual and biomechanical asymmetries resulted in increased df recruitment with no changes in coordination stability. Experiment 2 decoupled visual phase from biomechanical phase by reversing the marker mapping of one motion sensor. When visual information matched biomechanical information, coordination stability and df recruitment were higher. Similarly, biomechanically anti-phase conditions had less stability and more df recruitment than in-phase conditions. The third set of experiments manipulated feedback by either giving participants feedback about their accuracy in the x-y plane (i.e., motion around the targets; Experiment 3a) or feedback about their movement in the z-plane (i.e., df recruitment; Experiment 3b). Experiment 3a showed opposite results of Experiment 1(no df recruitment but a decrease in stability), again suggesting the same relationship between df recruitment and coordination stability. Experiment 3b showed that feedback about motion in the z-plane did suppress df recruitment. There were no differences in coordination stability across trials; however, performance accuracy was generally poor. Results of Experiment 3b were inconclusive. The present results collectively suggest that df recruitment does stabilize coordination, and that there is a tradeoff between df recruitment and coordination stability. It remains unclear, however, under which conditions df recruitment occurs (i.e., why actors elect to stabilize coordination via df recruitment in some circumstances but not others). The present results also suggest that both vision and biomechanics influence interlimb coordination dynamics. Visual and biomechanical symmetry both seem to stabilize coordination, presuming that df recruitment indexes threats to coordination stability. Similarly, both visual phase and biomechanical phase seemed to influence coordination. In Experiment 2, when visual information conflicted with biomechanical information (i.e., mismatch conditions) coordination stability was compromised compared to when the visual and biomechanical information matched. However, in addition to an influence of information congruence, biomechanical phase also influenced stability such that biomechanically anti-phase conditions had lower stability than biomechanically in-phase conditions.
Kevin Shockley, Ph.D. (Committee Chair)
Sarah Cummins-Sebree, Ph.D. (Committee Member)
Michael Richardson, Ph.D. (Committee Member)
Michael Riley, Ph.D. (Committee Member)
110 p.
Experiments
Interlimb coordination; degrees of freedom; stabilization; multimodal

Recommended Citations

Citations

  • Bachus, L. E. (2014). Recruitment of Degrees of Freedom based on Multimodal Information about Interlimb Coordination [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406819390

    APA Style (7th edition)

  • Bachus, Laura. Recruitment of Degrees of Freedom based on Multimodal Information about Interlimb Coordination. 2014. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406819390.

    MLA Style (8th edition)

  • Bachus, Laura. "Recruitment of Degrees of Freedom based on Multimodal Information about Interlimb Coordination." Doctoral dissertation, University of Cincinnati, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406819390

    Chicago Manual of Style (17th edition)

ucin1406819390
364
© 2014, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.