# From Patient to Musician: A Multi-Sensory Virtual Reality Rehabilitation Tool for Spatial Neglect
## 7 Results
### Assessment Task  
During the _Assessment_, the head direction of the users is recorded, resulting in traces for each user of each session. The average of all traces is calculated and compared for patients and test users. Figure 12 shows the first 60 s of the aggregations. The patients show a consistent bias of 20 to 30 degrees towards the non-neglected side during the first 11 s of each _Assessment_. After these 11 s, it appears that the average resides much closer to the centre of the playing area, albeit with a more significant standard deviation. This means that there is a large consensus among all patients to look at the non-neglected side during the first 11 s. The test users do not show this behaviour. Their average head direction is close to 0 degrees throughout the entire session. The standard deviation for the test users remains relatively consistent and is similar to that of the patients after the first 11 s. Figure 12 also indicates that, on average, the first key was played after approximately 11 s following the beginning of the traces.  
The bias of the head direction during the _Assessment_ task is further investigated. As the purpose of the _Assessment_ task is to assess the severity of the USN in a patient, it is interesting to compare it to the CBS scores of the patients. Figure 13 shows how the CBS score correlates to the average head direction during the first 11 s (left) and the remainder of the task (right). Participants with a CBS score close to zero consistently have an average head direction close to zero. As the CBS score increases, bias in the average head direction can be observed. During the first 11 s, all patients with CBS \(>\) 0 have a bias towards the non-neglected side. For the remainder of the task, patients with CBS \(<=\) 8 show no bias any more, and they position their head in the centre, while patients with CBS \(>\) 8 show a bias towards the neglected side.  
Figure 12: The average head direction of the first 60 s of all the _Assessment_ tasks is aggregated and plotted for the clinical patients (blue) and the non-clinical test users (pink). The patients indicate a bias of around 20 degrees towards their non-neglected side for the first 11 s, the average time until the first key is played (green). This bias is corrected after this first stimulus, resulting in an average head direction fluctuating around the middle for the remainder of the 60 s.  
However, when observing the difference between the averages during the first 11 s of the _Assessment_ and the rest of the task, a more significant correlation with the CBS score becomes apparent. In Figure 14, this difference is calculated and plotted against the CBS score. Indeed, the correlation appears linear within the range of CBS scores of 0 to 19. More specifically, users with a CBS score of 0 show minimal differences during the first 11 s and the remainder of the _Assessment_ task. The larger the CBS score, the more significant this difference in bias becomes. The patients appear to apply a correction to their head direction in order to observe more of the environment.  
Figure 14: The CBS scores of all participants are plotted against the difference between average head direction during the first 11 s and the remainder of the _Assessment_. These indicate a linear correlation with a bias towards the neglected side. The higher the CBS score, the greater the bias towards the neglected side of space.  
Figure 13: (**Left**) Users with a higher CBS score indicate a higher bias towards their non-neglected side compared to the users with a CBS score of 0. Within the patient sample, no significant difference in head direction can be observed based on the CBS score for the first 11 s. (**Right**) The CBS scores of all participants are plotted against the average head direction during the remainder of the _Assessment_. These show that the bias of the head direction has shifted towards the non-neglected side for users with a higher CBS score.