Cooperative bimanual action

We present an experiment on cooperative bimanual action. Right-handed subjects manipulated a pair of physical objects, a tool and a target object, so that the tool would touch a target on the object @g. 1). For this task, there is a marked specialization of the hands. Performance is best when the left hand orients the target object and the right hand manipulates the tool, but is significantly reduced when these roles are reversed. This suggests that the right hand operates relative to the frame-of-reference of the left hand.