Os efeitos do nível de estabilização do desempenho na adaptação a perturbaçoes perceptivas imprevisíveis

Abstract

The purpose this study was to investigate the effects of the levels of performance stabilization in the adaptation to unpredictable perceptive perturbations. Fifty one volunteers were randomly distributed in three groups: Control group (GC), Stabilization Group (GE) and Super Stabilization Group (GS). The experiment was conducted in two phases, named pre-exposure and exposure. In the pre-exposure phase, GE and GS practiced a pre-determined sequence of five sensors touches inorder of touching the last sensor in accordance to the visual stimulus arrival that moved to a constant speed and total displacement time of 2250ms. The experimental groups were differentiated by the performance stabilization level, determined from performance criteria. GE practiced the task until perform three trials in a row with absolute error less than or equal to 25ms, and GS has practiced the task until perform six blocks of three trials in a row with absolute error less than or equal to 25ms. When the first phase of the experiment got over, the exposure phase started,in which the three groups were submitted to 18 unpredicted perceptual perturbations, which consisted of speed combinations of the visual stimuli during displacement. The first speed had the initial portion with lower stimuli speed and higher speed in the final portion; the second speed had the initial portion with higher stimuli speed and lower speed in the final portion; however, the total time of stimuli displacement keepon the same as in the pre-exposure phase (2250ms). The unpredictability of the perturbations was guaranteed by the manipulation of the perturbation insertion moment, as well as by the randomness of the perturbation. The results showed that that: a) the level of performance stabilization influences the adaptation to unpredictable perceptive perturbations; b) the performance stabilization and super stabilization provides better adaptation to unpredictable perceptive perturbationswhen compared to the absence of previous practice; c) performance super stabilization provides better adaptation to unpredictable perceptive perturbations than performance stabilization; d) unpredictable perceptual perturbations with lower - higher visual stimuli speed combination are harder to be overcome than unpredictable perceptual perturbations with higher lower visual stimuli speed combinations. Keywords: stabilization level, adaptation, unpredictable perturbations, motor learning.