Linear and logarithmic speed-accuracy trade-offs in reciprocal aiming result from task-specific parameterization of an invariant underlying dynamics.
The authors examined the origins of linear and logarithmic speed-accuracy trade-offs from a dynamic systems perspective on motor control. In each experiment, participants performed 2 reciprocal aiming tasks: (a) a velocity-constrained task in which movement time was imposed and accuracy had to be maximized, and (b) a distance-constrained task in which accuracy was imposed and movement time had to be minimized. In Experiment 1, accuracy was constant across the 2 tasks; in Experiment 2, movement time was kept constant. Behavior in both tasks could be modeled with a single nonlinear equation of motion. Model coefficients captured the particulars of each task, especially apparent for the slowest or most difficult conditions. The distance-constrained task revealed a strong contribution of nonlinear stiffness with a moderate degree of nonlinear damping, favoring local control of speed. The velocity-constrained task revealed weaker nonlinear stiffness with stronger nonlinear damping, favoring global stabilization of the movement with a more constant rate of phase progression. In this way, the different speed-accuracy trade-offs emerged from the task-specific parameterization of the underlying dynamics.
Bongers
Raoul M
RM
University of the Mediterranean. R.M.Bongers@rug.nl
Fernandez
Laure
L
Bootsma
Reinoud J
RJ
D000222:Adaptation, Physiological; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007699:Kinesthesis / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D009068:Movement / Q000502:physiology*; D009949:Orientation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D013028:Space Perception / Q000502:physiology; D055815:Young Adult