 Equipment used --- Hand movements Hand movements are registered from above and the side by four infrared high-speed cameras Bonita Vicon-Cameras - CE mark 0088 which register with 250Hz the 3D positions of ten small reflexive markers attached by double sided adhesive tape to all fingertips and to the thumb of the subjects right hand. The cameras are connected via cables with an Ultranet which is the central processing unit. The Ultranet is connected with a network cable to a corresponding desktop computer. 