**Shadmehr R, Brashers-Krug T, Mussa-Ivaldi FA (1995) Interference
in learning internal models of inverse dynamics in humans. In: Advances in
Neural Information Processing Systems, vol. 7, G. Tesauro, D. S.
Touretzky, T. K. Leen (eds), MIT Press, pp. 1117-24.**

**Abstract** Experiments were performed to reveal
some of the computational properties of the human motor memory system. We show
that as humans practice reaching movements while interacting with a novel
mechanical environment, they learn an internal model of the inverse dynamics of
that environment. Subjects show recall of this model at testing sessions 24
hours after the initial practice. The representation of the internal model in
memory is such that there is interference when there is an attempt to learn a
new inverse dynamics map immediately after an anti-correlated mapping was
learned. We

suggest that this interference is an indication that the same computational
elements used to encode the first inverse dynamics map are being used to learn
the second mapping. We predict that this leads to a forgetting of the initially
learned skill.