December 7, 2021

I, Science

The science magazine of Imperial College

Could we one day hook our brain up to control the movements of an avatar? ...


We all know the concept of James Cameron’s Avatar: moving another body with your mind. In the film, paraplegic Marine Jake Sully is hooked up to inhabit the body of a genetically engineered Na’vi and so infiltrate the tribe. So far this has been dismissed as science fiction, but could new research make this a reality? Looking back over 2014, the research on this has seems more like an April fool’s prank but in one possible treatment for paralysis a monkey, the ‘master’, was able to move the arm of another monkey, the ‘avatar’, with thoughts alone.

The research was conducted at Harvard and Cornell universities in the US and published in Nature Communications. It wasn’t really just thoughts – there were lots of complicated electronics as well including 36 electrodes in the receiving monkey and a brain chip in the master monkey that tracked the activity of 100 neurons.

But the science is fascinating. Previous experiments have shown how hard it is to replicate nerve impulses that cause movement, so the researchers coded the aim of movement rather than the movement itself.

According to Dr Ziv Williams, one of the researchers and a neurosurgeon at Harvard University: “What we basically did was create a functional cortical-to-spinal bypass where we’re able to record neural signals in the brain, extract information about what the monkey is intending on doing and then, basically, stimulate the spinal cord to produce movements in the paralysed limb to those target locations.”

Patients have previously been able to control prosthetic limbs with their thoughts, but controlling paralysed limbs is a different challenge. The researchers hope that this study can provide proof of concept for a method that would potentially help paralysed patients regain some movement in their limbs.

Understandably, this has raised concerns. Comments on the I Fucking Love Science news story included: “like a step in the direction of mind control,” and a fear it could be used to commit remote controlled murder.

But the messages coming from the scientists are reassuring – don’t panic they say.  They don’t think this research will lead to humans controlling other bodies.

The researchers used separate monkeys to prevent having to paralyse one for the purpose of the experiment.  Sedating the second monkey had the same effect.  In humans, the idea would be to provide a ‘functional bypass’ to skip over damaged sections of the spinal cord and enable messages to be relayed from the brain to the paralysed limb.

It will take a lot more research, especially to get natural movement.  According to Dr Ziv Williams, one of the researchers who spoke to the BBC: “It will require an exponential additional effort to get to that point.”

And Professor Christopher James from the University of Warwick agrees this future is ‘a no-brainer’: “Whilst the control of limbs is sophisticated, it is still rather crude overall, plus of course in an able-bodied person their own control over their limbs remains anyway, so no-one is going to control anyone else’s body against their wishes any time soon.”

Image: Sam Worthington on