This is incredible experiment, I just can't resist to sharing it. There was new publication in Neuroscience News, researches has been going on for years, some of which is in the open access, you can look.
So far, third thumb is controlled non-invasively, by buttons in the shoe. But imagine what would happen if you combine this with neural interface.The interesting thing is, it seems to me, that it's easier to get used to it than to get used to being without it :)
It's actually a lot more serious than it looks. I think it's worth keeping an eye on this topic, there will be many more interesting things to come...
More links:
https://robotics.sciencemag.org/content/6/54/eabd7935/
https://www.daniclodedesign.com/thethirdthumb
https://www.ucl.ac.uk/icn/research/research-groups/plasticity/body-augmentation
https://plasticity-lab.com/body-augmentation
