Article

A STUDY OF CHAOTIC PHENOMENA IN HUMAN-LIKE REACHING MOVEMENTS

International Journal of Bifurcation and Chaos (Impact Factor: 1.02). 04/2012; 21(11). DOI: 10.1142/S0218127411030532
Source: dx.doi.org

ABSTRACT In this paper, the feasibility of observing chaotic behavior in the model of a human arm is discussed. Two-Link Arm driven by Six Muscles (TLASM) which is a well-known model of planar human arm reaching movements in the horizontal plane is investigated. Reinforcement learning (RL) that is considered as a model for Dopamine-based learning in the brain is used to control the TLSAM. Finally, the existence of chaos phenomena in the TLASM model controlled with RL is researched using tools like bifurcation maps, Lyapunov exponents, phase-plane trajectories, and spectral analysis using FFT. Results yield that chaos phenomena may occur in the overall system by changing some internal parameters of muscles that have a physiological explanation.

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