Mind and machine: moving from rehabilitation to restoration?

Many futuristic movies and books depict humans with upgrades.  Extra limbs or special abilities are common and some even create a hybrid of human and machine as in Robocop.  This post will look at just how real that hybrid is and how technology and neuroscience are allowing this to happen.

‘60 minutes’ in the US recently showed a segment that took a brief look at some new technology in neuroscience and robotics. The host, Pelley, was able to meet with participants, researchers and surgeons to discuss what this new frontier involved.

The story begins with Jan Scheuermann who suffered from spino-cerebellar degeneration leaving her essentially paralysed from the neck down.  This is where Andy Schwartz, a neuroscientist from Pittsburg University, came to offer something new and ultimately groundbreaking.  He proposed that electrodes could be placed on the motor cortex of Jan’s brain and that this could enable her to move a crafted robotic arm with her thoughts.

It is known that simply thinking about moving a body part activates the brain as if it was actually performing the movement.  Taking advantage of this, it was proposed that specific cortical signals could be taken and translated into robotic movement.  Five months after brain surgery, Jan was able to make a robotic arm move and interact with her environment simply by thinking about it.  This is where we see Jan shaking hands and even doing fist bumps with the researchers.

Amputees are probably the most obvious beneficiaries from this type of science.  By attaching sensors to the site of a relocated peripheral nerve to muscle where activity can be translated to a robotic limb without the need for brain surgery.  Sensory feedback from the limb is even possible where sensors on the prosthetic limb translate sensory information back to the person making the human-machine integration even more complete.

This comes as great news for amputees with phantom limb pain.  In fact, using a myoelectric limb replacement has been shown to reduce the cortical reorganisation that is typical of chronic pain (Grodd et al. 1999).  It was found that the more a patient used their prosthesis the less cortical reorganisation was seen.  Interestingly it was mentioned that no patient reported an increase in phantom limb pain when using a prosthesis.  It is possible that as technology allows prostheses to feel and act more like a real limb that cortical reorganisation will be even better prevented or reversed and phantom limb pain will be increasingly better treated. That is, because cortical reorganisation would be ‘greatest’ with no prosthesis or sensory feedback it should be ‘least’ when the prosthesis provides the most ‘life like’ replacement.

Some questions beg to be asked: can robotic limbs ever fully replace a human limb?  Can we recreate what evolution has taken billions of years to form?   Is complete restoration even possible?  Where do we stop?  Ultimately, will we end up discarding our flesh for better, stronger, longer-lasting artificial bodies?  If we are half robot, are we still fully human?

In conclusion, humans are highly adaptable and given the need, or even opportunity, we learn more and more about what we are capable of.  Perhaps we can make the move from making the best of a situation, as in rehabilitation, to complete restoration to premorbid levels.  Personally I can never be against anything that enables a person experience the world more fully. With science advancing as it is, these discoveries will become increasingly more common and soon Robocop may not be just fiction.

About Rohan Miegel

grey Mind and machine: moving from rehabilitation to restoration?Rohan Miegel is currently in his final year of Physiotherapy at the University of South Australia.  He has only recently become involved in research and is taking advantage of any opportunities.  Particular interests include neuroscience, pain, (very recently) cycling, and anything to do with dinosaurs.  He plans to finish his degree then dive more into the world of research.

Reference

Lotze M, Grodd W, Birbaumer N, Erb M, Huse E, & Flor H (1999). Does use of a myoelectric prosthesis prevent cortical reorganization and phantom limb pain? Nature neuroscience, 2 (6), 501-2 PMID: 10448212