Persistent coordination patterns in a complex task after 10 years delay

![CDATA[The aim of this experiment was to examine the qualitative behavioral reorganizations of a complex skill acquisition on a ski-simulator that occur after a long term delay. 10 years before, five subjects practiced for 39 sessions of ten 1-min trials on a modified version of the ski-simulator. In the present study, a retention test (10 years after) was conducted for 1 session of ten 1-min trials, with the same subjects in the same conditions. Analyses focused on the motion of the apparatus platform modeled as a self-sustained oscillator. At the beginning of the experiment, all subjects adopted a behavior that could be modeled with a moderate non-linear stiffness function, a van der Pol damping function, a frequency and amplitude values under the previous experiment. In the final part of the experiment we observed: a linear stiffness function, a van der Pol damping behaviour and frequency and amplitude values near but always under the previous study. The results indicate that the acquisition of expert pattern behaviour persists well over a long delay.]]