Amputees Feeling As If Prosthetic Belongs To Their Own Body

Underlying issue to this seems to be twofold: amputees still feel ther missing limb, even if its a ghost limb; and commercially available prosthetic limbs as of yet do not provide sensory feedback other than what is seen such as touch must be constantly watched for correct use.

The brain uses senses to evaluate what belongs to body and what is external, EPFL’s Laboratory of Cognitive Neuroprosthetics in collaboration with EPFL and Scuola Superiore Sant Anna Italy scientists have shown how vision and touch can be combined to trick amputee’s brains into feeling what it sees inducing embodiment of prosthetic hands with effect of phantom limbs growing into the prosthetic in a portable setup that could be turned into therapy to help patients embody their prosthetic limb permanently.

Scientists have provided two hand amputees artificial tactile sensations at tip of index fingers on phantom limbs by stimulating nerves in stumps while the patient wore virtual reality goggles showing the index finger of the prosthetic limb growing in synchrony with administered touch sensations; combination of virtual reality with artificial tactile sensations takes illusion to another level: therapeutic.

Patients reported feeling as though prosthetic hands belonged to their own bodies, when asked to evaluate position of hands patients felt as though phantom limbs had extended into the prosthetic. Prior to the experiment patients reported phantom land was small and connected directly to the stump. Phantom limbs extended during experiments and remained that way for up to 10 minutes.

Patients are required to passively observe 2 sensations on the fingertip: visual glow and artificial touch happening in synchrony for embodiment and extension of phantom limb to take place. This marks the first known time principles of multisensory integration of how the brain integrates multisensory information to create coherent and compelling experience of having body have been tailored to provoke embodiment of prosthetic hands and reduction of telescoping.

Scientists built upon previous work opening new paths in prosthetics overcoming major hurdles by giving amputees ability to feel in real time with help of prosthetic hands. Information of touch coming from sensors at prosthetic fingertips were directly processed and relayed to the nervous system via electrodes surgically wired to stump’s main nerves; potential of this technology is still being explored, enhanced prosthetic technology could help the same amputee detect differences in texture.