The idea that humans have wings, tentacles, or an extra arm all seem rather unlikely.
But these scenarios could become reality in the coming decades, thanks to leaps in human augmentation.
Researchers have already designed a “third thumb” controlled by foot movements that would allow the wearer to unscrew a bottle, peel a banana or insert a needle with just one hand.
Now experts believe the thumb is just a first step toward bigger, more dramatic additions to the human body.
Tamar Makin, a professor of cognitive neuroscience at the University of Cambridge, said the brain’s ability to adapt to an extra limb was “extraordinary.”
The idea that humans have wings (artist’s impression), tentacles or an extra arm all seem rather unlikely. But these scenarios could become reality in the coming decades, thanks to leaps in human augmentation
But scaling up the design to larger augmentation devices comes with its own hurdles.
“The big question is how do you control a body part you’ve never had before?” she said.
“When we work with replacement technology, such as prosthetics, the goal is quite simple.
‘But in addition, I want you to continue to use your body optimally and also give you an extra body part.
“We also worry about what we call the resource redistribution problem — what if I steal resources from the feet to give one to the hands?”
When asked if it would be possible to design wings or even tentacles for human use, Professor Makin said: ‘Yes, technically. The technologies are there, we just need to scale them up.
‘There are technological problems, for example you want it to be portable and comfortable, not to be heavy and not to plug into a socket.
Control is the real problem. So wings are actually very simple because it’s just one degree of freedom – up and down.
“But when you do something more complicated, like a tentacle, we need a lot of control.
“For example, if you want to get to your cup of coffee because it’s far away, you want to use your tentacle.
“But if you really need to concentrate because it’s a really complicated task, then just getting up is less distracting.”

When asked if it would be possible to design wings or even tentacles for human use, Professor Makin said: ‘Yes, technically. The technologies are there, we just need to scale them up’

Researchers have already designed a ‘third thumb’ controlled by foot movements that would allow the wearer to unscrew a bottle, peel a banana or thread a needle with just one hand
Her colleague Dani Clode was the mastermind behind the Third Thumb, which was first revealed in 2017.
The robotic 3D-printed digit is worn on the side of the hand opposite the user’s actual thumb.
The wearer controls it with pressure sensors attached to their feet, on the underside of the big toes, with a wireless link connecting the two.
For their study, 20 participants were trained for five days to use the thumb, for example to pick up several balls or wine glasses with one hand.
They learned the basics of the thumb very quickly and could even use it while distracted or blindfolded.
In the journal Science Robotics, the team writes that participants also increasingly feel that the thumb is part of their own body.

The robotic 3D-printed digit is worn on the side of the hand opposite the user’s actual thumb
Before and after the training, the researchers scanned the participants’ brains. They discovered subtle but significant changes in the organization of neural circuits that light up when we use our hands.
Professor Makin said: ‘Evolution has not prepared us to use an extra body part, and we have found that in order to expand our capabilities in new and unexpected ways, the brain has to adapt the representation of the biological body.’
Ms. Clode has also designed a robotic, retractable tentacle that acts as a prosthetic arm.
Dubbed ‘Vine 2.0’, it has 26 individual vertebrae that are controlled by the wearer using pressure sensors and electronics in shoes.
Silvestro Micera, of the Sant’Anna School of Advanced studies in Pisa, is also working on a third arm that will be attached to the body around the waist and controlled by breathing.
The researchers will discuss their advances in augmentation at the annual conference of the American Association for the Advancement of Science in Washington.
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