Analysis of variability of human reaching movements based on the similarity preservation of arm trajectories

Abstract

Human movements exhibit some variability. Based on the assumption that the main factor of movement variability is noise adding to motion commands in motion execution, it can be considered that a planned trajectory is the same during the same task. However, the human might not be able to plan the same trajectory during the same task because of some factors (e.g., the uncertainty of target location perception). We analyzed the similarity preservation of trajectories in reaching movements. The similarity preservation of trajectories cannot be reproduced by random noise in motion execution. We argue that the movement variability breaks out in motion planning. © 2008 Springer-Verlag Berlin Heidelberg.