Visualizing the third dimension in virtual training environments for neurologically impaired persons: beneficial or disruptive?

Background: Many contemporary systems for neurorehabilitation utilize 3D virtual environments (VEs) that allow for training patients' hand or arm movements. In the current paper we comparatively test the effectiveness of two characteristics of VEs in rehabilitation training when utilizing a 3D haptic interaction device: Stereo Visualization (monoscopic vs stereoscopic image presentation) and Graphic Environment (2.5D vs 3D).