Two-component models of reaching: Evidence from deafferentation in a Fitts' law task

NEUROSCIENCE LETTERS

卷:451

Article

Medina, Jared^1,2  Jax, Steven A.³  Coslett, H. Branch^1,2 

[1] Univ Penn, Dept Neurol, Philadelphia, PA 19104 USA

[2] Univ Penn, Ctr Cognit Neurosci, Philadelphia, PA 19104 USA

[3] Moss Rehabil Res Inst, Philadelphia, PA 19141 USA

关键词: Fitts' law;    Proprioception;    Deafferentation;    Motor control;   

DOI  :  10.1016/j.neulet.2009.01.002

来源: Elsevier

【 摘 要 】

Both feedforward and feedback mechanisms are used to ensure accurate movements. Feedback information comes primarily from vision and proprioception; the relative contributions of these modalities to on-line control of action and internal model maintenance remain unclear. We report data from an experiment in which a chronically deafferented subject (JDY) and nine controls were asked to reach to targets of different sizes both with and without vision. Movement times of controls were consistent with Fitts' law on trials with and without vision. JDY's movement times were consistent with Fitts' law only with vision. She was inaccurate relative to controls with vision but exhibited a significantly greater decrement in performance than controls without vision. Finally,JDY's performance on trials with vision deteriorated as a function of the number of preceding trials on which vision was not available. These data provide support for classical models of motor control that divide reaching into an initial ballistic movement guided by efference copy, and a terminal stage where sensory feedback is crucial. Furthermore, these data also demonstrate that proprioception is needed to calibrate and maintain internal models of action. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

【 授权许可】

Free