Self-Control of Task Difficulty During Early Practice Promotes Motor Skill Learning.

This study was designed to determine whether the effect of self-control of task difficulty on motor learning is a function of the period of self-control administration. In a complex anticipation-coincidence task that required participants to intercept 3 targets with a virtual racquet, the task difficulty was either self-controlled or imposed to the participants in the two phases of the acquisition session. First, the results confirmed the beneficial effects of self-control over fully prescribed conditions. Second, the authors also demonstrated that a partial self-control of task difficulty better promotes learning than does a complete self-controlled procedure. Overall, the results revealed that these benefits are increased when this choice is allowed during early practice. The findings are discussed in terms of theoretical and applied perspectives.

Attentional focus effects on sprint start performance as a function of skill level.

Several researchers have demonstrated that an external focus of attention (about movement's effects) during movement execution allowed better performances and learning of various motor tasks than an internal focus of attention (about movement itself). However, attentional focus effects have not been studied in tasks requiring explosive actions preceded by fast reaction time to a signal, such as a sprint start. We hypothesised that the beneficial effect of external focus of attention would be observed in the different stages of the sprint start (i.e., reaction time, block clearance and running) for both expert and novice sprinters. Novice and expert sprinters performed sprint starts followed by a 10 m sprint under three conditions: external focus instructions; internal focus instructions; and neutral instructions. The reaction time and the running time were significantly shorter in the external focus condition than in the internal focus condition, for both expert and novice participants. These results confirm the beneficial effect of an external focus of attention on the speed of movement execution. Moreover, they revealed that attentional focus influences movement preparation. Several hypotheses are proposed to account for these results, with reference to the processes that could be responsible for the observed effects.

Self-control of task difficulty during training enhances motor learning of a complex coincidence-anticipation task.

The aim of the present work was to analyze the influence of self-controlled task difficulty on motor learning. Participants had to intercept three targets falling at different velocities by displacing a stylus above a digitizer Task difficulty corresponded to racquet width. Half the participants (self-control condition) could choose the racquet width at the beginning of each trial. Each was paired with a participant from the yoked group. The self-control condition resulted in better performances and accuracy during immediate and delayed retention tests. These results confirm the advantage of a self-control condition on motor learning. They are discussed with reference to the challenge point hypothesis (Guadagnoli & Lee, 2004).

Interactions between human explicit and implicit perceptual motor learning shown by kinematic variables.

The goal of this study was to investigate in non-impaired humans the interaction between explicit and implicit learning in a catching task. The situation presented probabilistic contingencies between visual signals and various final pathways of the target. Subjects were asked to practice the interception task for 320 trials. Explicit instructions describing the probabilistic rules were given prior to (11 subjects), or in the middle of (11 subjects), physical practice. Eleven subjects not provided with verbal instructions served as control subjects. We measured the combination between explicit verbal instructions and implicit learning via kinematics of the end-effector and an outcome measure (i.e. spatial error). The time when explicit instructions were given resulted in systematic changes in the spatio-temporal ordering of the action. These data suggested that analyzing the way the task is executed with scrutiny allows a new understanding of how the aforementioned learning systems interact.