Acceso usuarios
Two different models are currently used to account for the processes involved in a motor task. Centralist models describe movement production with a modular architecture, in which modules are responsible for planning, for activation of motor programs, and for recruitment of the different effector units. According to dynamic models, part of the movement parameters may result from the physical properties of the effectors. In two experiments, we show that both kinds of models are pertinent to explain movement control, but are dependent on the task demands. In a first experiment, adults drew patterns made of three straight lines and two acute angles with a repetition of series composed of patterns with increasing and decreasing sizes. Peripheral processes are mainly expressed through the exploitation of elasticity of muscles and tendons. However, more central processes are needed when the task elicits a repetition of the same motor programs. In a second experiment, a dual-task paradigm mobilizing the subject's attentional resources influenced the use of peripheral processes as shown by the regression to an optimal movement amplitude.
