Abstract
Victims of a stroke or an accident with damage on the parietal lobe can suffer from hemispatial neglect. This disorder is characterized by misperception of the space contralateral to the damaged area. Paper and pencil tests, such as line bisection tests, are used to diagnose hemispatial neglect. Unfortunately, they fail to quantify the degree of the neglect. Moreover, the neglect has different manifestations in each sensorial space and frame of references. In order to diagnose disorders of spatial recognition and analyze the neglected area in visual and somatic spaces, we developed a 3D-haptic virtual reality system coupled with an eye-tracking device. The haptic interface was used to interact with virtual objects. The virtual world can use the eye-gaze information to let patients overcome the neglect. We tested the system at a rehabilitation center and observed different approaches between normal subjects and hemiplegics patients. The first group was getting close to the target and then slowed down to grab it, whereas the later group proceeded by trial and error. The feature of trajectories of the hand in the 3D space could be used to determine the degree of the motion handicap. However, more specific virtual worlds are needed for efficiently extracting the feature of the patients.