Experiments were done to determine whether the starting position of the arm influences its final configuration (posture) when pointing to, or grasping, targets located within the common workspace of the arm. Subjects were asked to point to, or grasp, each of six targets from five, or seven, widely spaced starting positions. We found that the variability (standard deviation) of the arm’s configuration, measured as the angle of inclination of the plane delimited by the arm and forearm, averaged about 4° for comfortable speed pointing movements and was only slightly higher for fast pointing movements. Comfortable speed reaches to grasp the targets were associated with slightly lower variability (3.5°) in final arm configuration. The average variability of repeated movements to a given target from a single start position (3.5°) was comparable to that of movements from different start positions to the same target (4.2°). A small difference in final arm inclination angle, averaged across all subjects and targets, of 3° was found between two pairs of starting positions. This small and possibly idiosyncratic effect is within the “noise” of final arm orientation variability for repeated movements (i.e., 3.5°). Thus, the variability of final posture is not for the most part due to different start positions, it is inherent to movement per se. Our results reconcile conflicting previous studies and are consistent with past works suggesting that a Donders’ like law is indeed largely upheld for unconstrained visually guided arm movements. In summary, considering movements within a typical work space, when the hand is moved voluntarily to a given spatial location the posture of the arm is nearly the same regardless of its starting position. Importantly, variability is inherent to the rule. ; Open-Access Publikationsfonds 2016 ; peerReviewed


    Zugriff

    Download


    Exportieren, teilen und zitieren



    Titel :

    A Donders’ Like Law for Arm Movements: The Signal not the Noise


    Beteiligte:

    Erscheinungsdatum :

    2016-01-01


    Anmerkungen:

    27065836



    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch



    Klassifikation :

    DDC:    629




    Locomotor-like leg movements evoked by rhythmic arm movements in humans

    Sylos Labini, F / Ivanenko, Y / Maclellan, M et al. | BASE | 2014

    Freier Zugriff

    Directing train movements by signal indication

    Engineering Index Backfile | 1925


    Output Signal-to-Noise Ratios for Amplitude-Modulated Noise-Like Lasers

    Oshita, Shinjiro / Ueda, Hirotada / Morinaga, Norihiko et al. | IEEE | 1974


    Generating human-like movements for robotic arms

    Zhao, Jing | Online Contents | 2014


    Traffic Assignment with Turning Movements at Signal Intersection

    Lim, Y. | British Library Conference Proceedings | 1998