Efeitos do nível de estabilização do desempenho na adaptação a perturbações imprevisíveis inseridas após o início do movimento

Abstract

The aim of the present study was to compare the effect of two levels of handling performance stabilization on adaptation to unpredictable perturbations in an interception task. The study included forty volunteers (n = 40), right-handed college students without experience in the task, divided into two groups as a function of the level of stabilization of performance: GE (stabilization group) and GS (superestabilization group). The instruments used were a computer, a tablet and a digital pen. The task consisted of intercepting a virtual target with a fast movement along a specific space on the tablet. The experiment consisted of two phases: pre-exposure and exposure. On pre-exposure two levels of stabilization of the performance were manipulated: stabilization (GE), which should perform three interceptions in a row and superestabilization (GS), which should perform six blocks of three interceptions in a row. On exposure phase the perturbations related to changes in speed (PI - PII and increase - decrease) displacement of the target after the subject has started the movement were inserted. The outcome measures were: absolute spatial error (cm), spatial constant error (cm), number of trials made by each group in the pre-exposure, time to peak velocity (ms) and number of corrections in the movements. For data analysis it was run t-Student and two-way ANOVA, when necessary was used a post hoc. The analysis of the pre-exposure phase indicated that both groups improved performance throughouth the phase, that the strategy of control was predominantly pre-programming and that the GS performed more trials than GE. In the exposure phase, the analysis detected that the GS has adapted into a block of PI and two blocks of PII; the GE did not adapt to any block of any perturbation. The mechanism of control predominantly adopted by GS to adapt to the perturbation was the feedback. The results allowed concluding that the level of stabilization of the performance influences adaptation, indicating that motor learning is a continuous process