| Popis: |
In soccer or basketball, a player often passes a ball to a teammate. This is an example of coordination between individuals with a common goal in a motor task. Such coordination may occur intentionally and has recently been termed “joint action”. In practical events such as ball games, players have to pass a ball to a teammate even if opposing players interrupt the passing of the ball. In our previous studies on joint action we found that the force produced by two people is complementary. The optimal feedback control theory predicts that as the error produced by the participants increases, error compensation also increases. The present study thus tested the hypothesis that an interruption facilitates complementary force production but negatively influences performance during joint action. Twenty−one students performed both control and interruption experiments. In the control experiment, two participants produced a target force such that the sum of the discrete peak forces produced by their right index fingers was 10% of maximum voluntary contraction. In the interruption experiment, two cooperative participants（participants a and b）produced the same target force as the control experiment, and another participant（participant c）interrupted the peak forces produced by participant b. The force produced by the index finger or thumb of participant c decreased or increased the force produced by participant b. Both experiments consisted of eight blocks, with 50 trials in each block. The interruption was constant across blocks. The correlation between the forces produced by two cooperative participants was more negative in the interruption experiment than in the control experiment. The magnitude of the absolute error and standard deviation of force was greater in the interruption experiment than in the control experiment. These new findings indicate that interruption caused performance to deteriorate during joint action, but facilitated complementary force production. |
