Aim: This study aims at evaluating how exactly we can understand and remember given force information.
Methods: A forceps is attached to the PHANToM Premium 6DOF's stylus. By manipulating the forceps one can touch virtual objects. Nine subjects participated in this study. First, an object with certain stiffness kg, is presented: the subject can touch and learn its stiffness for 15 seconds. Then, following 15 seconds intermission, 20 objects with gradually different stiffness are presented. The subject touches these objects and chooses one of them, that has the same stiffness as the object presented before the intermission. This test is repeated 16 times for different kg.
Results: The average 'remembered' stiffness kr is in close agreement with the given stiffness kg, but its variation is large (0,12<SD/kg<0.60).
Conclusions: We can roughly remember the object's stiffness from force-feedback through a forceps.