Do Changes in Movements after Tool Use Depend on Body Schema or Motor Learning?

In a recent study, Cardinali et al. (2009) showed that training the use of a tool affected kinematic characteristics of subsequent free movements (i.e., movement were slower, for instance), which they interpreted as that the use of a tool affects the body schema. The current study examined whether these results can also be explained in terms of motor learning where movement characteristics during tool use persist in the free movements. Using a different tool we replicated parts of the study of Cardinali et al: As did Cardinali et al. we found that tool use after-effects can be found in subsequent free movements. Importantly, we showed that the tooling movement was very slow compared to the free hand movement. We concluded that it can not be ruled out yet that after-effects of tool use originate from a general slowing down of movement speed that persists in free hand movements.