Precocity of fine motor control and task context: hitting a ball while stepping

To determine if children under 5 years were able to intercept a moving object while stepping, the authors had 9 3-year-olds hit a ball that the authors dropped from a ramp from 5 heights (1.5, 2.0, 2.5, 3.0, and 3.5 m). The statistical analysis showed that the hand movement times were similar regardless of ball rolling heights and that the hand initiation times were dependent on the ball rolling times. Children under 5 years were able to hit a moving ball, and they performed this hitting according to a temporal coupling between ball displacements and the hand contact with it. The participants' behavior of hitting while stepping supports the idea that the motor system implicitly knows what the cognitive system ignores.