"Conhecimento de resultados no processo adaptativo em aprendizagem motora"

Abstract

Motor learning is a ciclic, dynamic and adaptive process, in which motor skills are stabilised and used in more complex situations. To understand motor skill acquisition as an adaptive process, it is necessary to break down the achieved stability in order to reach higher levels of complexity. Thus, instability, uncertainty, disorder, and error might act as positive features in this process. Considering KR as a source of order/disorder, this study aimed to investigate which frequency (33%, 66% e 100%) and precision (general and specific) KR schedules benefit the adaptive process in the acquisition of a linear positioning and manual force control combination motor task. A hundred and twenty undergraduate students ranging from 18 to 39 years (mean age = 25 yr., standard deviation = 4.5 yr.) were randomly assigned to six groups of 20 subjects each (ten male and ten female). In the first phase of the experiment (stabilisation), the subjects performed the motor task receiving verbal KR about the immediately finished trial that provided information about accomplishing the goal of 20% of the maximum force and 35 cm of displacement. The criterion to complete this phase was to perform two consecutive trials inside the error bandwidth. In the adaptation phase, 15 non-KR trials were performed on the same task, but with an environmental perturbation involving a traction force of xv about 2 kgf in the opposite direction of the movement. It was developed and used an apparatus enabling a linear positioning combined with a manual force control task. The subjects performed blindfolded and with the non-dominant hand. Absolute, constant, and variable errors measures were used to analyse the learning process. According to the stabilisation phase results, there were evidences that frequent and specific KR produced improvement of performance. The groups, on both task requirements (force and distance), reduced the level of errors from an initial to a posterior point in time with exponential trend, which is an evidence of learning occurrence. Results from the second phase indicated that the adaptation to the introduced perturbation was not related to KR frequency and precision provided in the stabilization phase. Data from both requirements fitted in a model with significant variance at the beginning. However, there was response heterogeneity throughout the trials in the distance requirement. Moreover, results revealed from low to moderate tracking, that is, subjects did not perform with stability, what reduces the probability to preview the performance of each group and each subject. A few amount of subjects exhibited absence of error randomness, which could express some performance trend, that is, a consistent strategy along trials. It can be concluded that it is not necessary to excessively diminish uncertainty by means of KR schedules with high frequency and precision.

Precisão do conhecimento de resultados no processo adaptativo em crianças

“…Considerando que para a aprendizagem ocorrer deve haver incerteza presente no sistema, mas que ela seja passível de ser reduzida (GuadaGnolli & lee, 2004), esperava-se que regimes de CR muito específicos (GMP) ou muito genéricos (GPP) pudessem não surtir efeito positivo na aprendizagem. Além disso, em dois estudos na abordagem do processo adaptativo (meira Júnior, 2005;tani, meira Júnior & GomeS, 2005) a maior precisão de CR pareceu não ser necessária para esse processo.…”

A prática constante-variada e a aquisição de habilidades motoras: efeitos da quantidade e do tipo de prática variada

“…A segunda linha de pesquisa refere-se à investigação da aquisição de habilidades motoras em função da manipulação dos fatores feedback (Meira Júnior, 2005;Tani, Meira Júnior 85 Gomes, 2005;Ugrinowitsch, Tertuliano, Coca, Pereira & Gimenez, 2003) e prática (Corrêa, 2001;Corrêa, Benda & Tani, 2001;Corrêa, Benda, Meira Júnior 8b Tani, 2003;Corrêa, 2003;Paroli, 2004). Em relação ao fator feedback, o conjunto de resultados ainda é inconclusivo.…”