Swiss scientists have shown that virtual reality (VR) can be used to make amputees feel as though their prosthetic equipment belongs to their own body.
Researchers combined VR with artificial tactile sensations to show that a phantom limb can grow into a prosthetic hand.
The report claims that many amputees opt out of prolonged use of their prosthetic limb because their missing limb “does not fit their prosthesis”.
In other words, a user’s own perception of the missing limb, or the brain’s representation of it, does not match-up with what they see of the prosthesis.
Amputees still feel their missing limb, even if it is physically gone, and this phantom limb is perceived as much smaller that the lost limb.
The report stated that commercially available prosthetic limbs do not yet provide sensory feedback other than what the patient sees, meaning that the patient has “no sense of touch” from the prosthetic limb and must constantly watch it for correct use.
Now, in a scientific collaboration led by EPFL (Ecole polytechnique fédérale de Lausanne), scientists show that amputees can be convinced that the prosthetic hand belongs to their own body.
They do this by going beyond the “seeing is believing” idiom based on established research on how the brain identifies what belongs to its own body.
Instead of using the sense of sight alone, they used a combination of sight and touch. The results have been published in the Journal of Neurology, Neurosurgery & Psychiatry.
Giulio Rognini of EPFL’s Laboratory of Cognitive Neuroprosthetics led by Olaf Blanke, said that the brain regularly uses its senses to evaluate what belongs to the body and what is external to the body.
“We showed exactly how vision and touch can be combined to trick the amputee’s brain into feeling what it sees, inducing embodiment of the prosthetic hand with an additional effect that the phantom limb grows into the prosthetic one.
“The setup is portable and could one day be turned into a therapy to help patients embody their prosthetic limb permanently.”
EPFL’s Laboratory of Cognitive Neuroprosthetics worked in collaboration with Silvestro Micera of EPFL and Scuola Superiore Sant’Anna in Italy.
Image credit: EPFL