| dc.description.abstract | Phantom sensations are frequently seen in amputees, and occur in some mental disorders like Alzheimer’s and Parkinson’s disease. Despite their common occurrence, there are several complicating factors that make it difficult to elucidate the underlying cause of the phantom sensation. The brain often undergoes complex neural reorganization after limb damage, and some neurological diseases like Parkinson’s degenerate and destroy the nerves themselves. In addition, the symptoms often appear sporadically and present differently among different patients, making it difficult to work with in a clinical environment and presenting challenges for data collection. All of these factors make it difficult to derive a robust theoretical model to explain the phantom sensation. A way to easily evoke the phantom sensation in a healthy-bodied subject would make it much easier to determine its mechanism, which would help lead us towards developing a cure. In this work, we propose a simple test to evoke the phantom sensation. A sharp pencil moving towards a subject's forehead, but not touching it, can create a tactile hallucination. The tactile hallucination can also be created entirely through virtual reality, with no physical contact. In our experiments, we found that this sensation is created by visual feedback, is directly correlated to the perceived risk of the moving object, and even measurably influences the subject's tactile sensitivity. We use this information to propose an addition to the standard sensorimotor model that can explain these phantom sensations. | en |
