Hopkins scientists shed light on how the brai...( milk bottle with an empty lighter one....)

The subject working the arm decides how to modify the much-altered model of reality. The paper describes mathematically how that happens.

First comes the process of unlearning the old paradigm before learning the complex new one. The subject has to think: "If I make my next movement, how will that affect my other movements? You changed the world for me; I see errors. If the errors are big enough, I have to reconsider the entire model." The next move the subject makes likely is worse than the one before until the subject starts realigning the primitives correctly.

Because the changes in the reality were done deliberately, not randomly, Shadmehr has been able to predict with considerable accuracy what the subsequent moves will be, how the primitives are changed.

Experiments show that the theoretical limits are closely observed in people's learning abilities. In other words, humans have a limited number of primitives to deploy when learning skills.

'"/>

Contact: Gary Stephenson
gstephenson@jhmi.edu
410-955-5384
Johns Hopkins Medical Institutions
11-Oct-2000