Characteristics of Human 3D Transport Movements during Obstacle Avoidance

Abstract

Event Abstract Back to Event Characteristics of Human 3D Transport Movements during Obstacle Avoidance Britta Grimme1*, John Lipinski1 and Gregor Schöner1 1 Ruhr-Universität Bochum, Institut für Neuroinformatik, Germany Theoretically, our arm motor apparatus enables the hand to follow any number of paths in order to reach for a target. This is due to many more degrees of freedom than needed to achieve a motor goal. In the presence of an obstacle, however, extra degrees of freedom (DOF) help: they expand the workspace and enable the arm to avoid the obstacle providing alternative ways towards the target. In fact, many every day arm movements are obstacle avoidance tasks that utilize the flexibility in the motor apparatus. Although many studies provide model frameworks, conclusions, or even empirical laws, they rarely rely on naturalistic 3D movements in which objects are transported relative to a surface but mostly on scribbles or drawing movements. Specifically, most obstacle avoidance studies are performed in 2D. Those investigations provide a basis for theoretical description of movements and identify important characteristics like planarity, the 2/3 power law (which describes a systematic relationship between curvature of end-effector path and velocity of movement), and bell-shaped velocity profiles. In this work, we analyze properties of 3D end-effector movements during an obstacle avoidance task to broaden insight into natural movement generation. Specifically, we investigate whether the mentioned principles also hold in those movements performed by the unconstrained 10 degree of freedom arm. In our experiment, five right-handed subjects performed a simple obstacle avoidance task on a table by relocating a cylindrical object from a starting position to a target position in straight ahead direction. During movement subjects had to avoid an obstacle of varying height and position. First, although virtually unrestricted in space, obstacle avoidance tasks are approximately planar. Second, near the obstacle—where curvature peaks—we often find a decrease in speed resulting in a double-peak velocity profile. However, slowdown is not sufficient to maintain the 2/3 power law. From these findings we can conclude that the impact of an obstacle is stronger at the level of curvature whereas the speed profile is less influenced. As such, the spatial paths seem to adapt stronger to the obstacle than the temporal dynamics of movement which may imply that both components are resolved separately in the nervous system. Figure 1: Single trial 3D spatial paths are depicted for four different obstacle positions (2 distances: close, far; 2 directions: near, far).Colors indicate different subjects. S: start, O: obstacle, T: target. Figure 1 Keywords: computational neuroscience Conference: Bernstein Conference on Computational Neuroscience, Berlin, Germany, 27 Sep - 1 Oct, 2010. Presentation Type: Poster Abstract Topic: Bernstein Conference on Computational Neuroscience Citation: Grimme B, Lipinski J and Schöner G (2010). Characteristics of Human 3D Transport Movements during Obstacle Avoidance. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference on Computational Neuroscience. doi: 10.3389/conf.fncom.2010.51.00002 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 07 Sep 2010; Published Online: 22 Sep 2010. * Correspondence: Dr. Britta Grimme, Ruhr-Universität Bochum, Institut für Neuroinformatik, Bochum, Germany, britta.czech@rub.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Britta Grimme John Lipinski Gregor Schöner Google Britta Grimme John Lipinski Gregor Schöner Google Scholar Britta Grimme John Lipinski Gregor Schöner PubMed Britta Grimme John Lipinski Gregor Schöner Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.