Movement automaticity as functional variability

Functional variability has been suggested to reflect movement automaticity. To test this hypothesis, we used the Uncontrolled Manifold (UCM) approach to operationalize functional variability in darts. We gauged the association between movement automaticity and functional variability in four different ways. First, we investigated whether functional variability was higher in the second half of a throw than in the first half, because the duration of a darts throw is too short for conscious control to intervene. Second, we compared whether functional variability was higher in experts than in novices, because motor control is presumed to be more automatized in experts. Third, we manipulated conscious control via attentional focus instructions, presuming that internal focus instructions result in reduced automaticity, and thus may decrease functional variability. Fourth, we administered the Movement Specific Reinvestment Scale (MSRS), which estimates the propensity for conscious control and was therefore expected to be associated with functional variability. In line with the hypotheses, functional variability was higher in the second half than in the first half of darts throws. Furthermore, experts displayed more functional variability than novices. These results suggest that functional variability reflects movement automaticity. However, neither the focus manipulations, nor MSRS scores significantly predicted functional variability. Further study is therefore required to ascertain whether functional variability reflects movement automaticity.