City Research Online

Abstract

Although the underlying principles of the spatiomotor dynamics during human movement execution are now broadly understood to conform to a minimum jerk principle, the question addressed in the present analysis is whether different principles operate during human drawing movements without visual input, deriving from studies of the Likova Cognitive-Kinesthetic Memory-Drawing Training. For two groups of participants, completely blind, and sighted but temporarily blindfolded, this analysis shows that the consensus model of arm-motion kinematics as a simple one-third power relationship of drawing speed to the local curvature of the line being drawn is not a sufficient characterization of their coupling. Instead, the drawing dynamics without visual feedback conform to a hyperbolic power relationship, with a coupling power of approximately 1.0 for regions of the highest curvature, asymptoting to curvature-independence for regions of shallow curvature, for both blind and blindfolded groups. Thus, the asymptotic power was much higher than the one-third power predicted by the minimum jerk principle. In detail, the maximum-velocity asymptote for both groups averaged about 6 cm/s for drawing from memory, increasing to more than twice as fast for mindless scribbling. We conclude that the more elaborate operating principle of a hyperbolic saturation function, with a power asymptote of about 1.0, may be interpreted as an adaptive implementation approximating the Minimum Jerk Principle of the simple one-third power law relating velocity and curvature.

Publication Type:	Article
Additional Information:	Copyright © 2025 The Authors. Licensed under Creative Commons Attribution CC-BY-NC-ND 4.0. Published by the American Physiological Society.
Publisher Keywords:	hand movements, manual dexterity, minimum jerk principle, power law, spatiomotor dynamics
Subjects:	R Medicine > R Medicine (General)
Departments:	School of Health & Medical Sciences School of Health & Medical Sciences > Optometry & Visual Sciences
SWORD Depositor:	Symplectic Administrator

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