Is That My Real Hand? | Breakthrough

Well, there's a lot of interest in the robotics community. How can we extend the human body, not only with advanced prosthetic limbs for amps, but maybe for exoskeletons? And then, of course, the question is at what point do these external devices become part of your own body representation?

At one point, do you start to feel that this is really me? Sitting in the lab with Henrik and Andreas, one of Henrik's postdocs, I'm about to be put through the rubber hand experiment. "Put your arm here onto the table and inside this little box here. Okay, cover your right side here now."

"Okay, so what I would do now is I will touch your index finger with the brush here, and please look to the index finger of the hand here." Okay, with my hand hidden from view, Andrea starts to stroke my index finger and the index finger of the rubber hand in almost perfect synchrony.

What you experience, I think, is genuinely beginning to become hard to tell whether—yeah, I mean, it's beginning to feel like—yeah, yeah, I'm buying it, that you're rubbing, that you're swiping. That part of my brain is telling me that it's not possible that that's happening, you know? And then when you're not touching it, I go, "No, not happening." Then you touch it, and I'm like, "Yeah, I'm feeling it there." It's totally—now, just, there’s no question that that's my hand, that that's what you're touching.

All that's the—that's the first experiment. That's crazy! That's super crazy! When they connect my finger with the rubber hand's finger and introduce movement to the experiment—well, now the illusion gets totally surreal. "Oh my God, that's my—that's crazy! That's really weird! Oh man, that's nuts!"

There was a real moment where it suddenly switched. I was like, "Now this isn't working," and then suddenly, now it's just—again, the more I'm doing it. But that's the thing, now I'm not doing anything—now you do! That's crazy! I'm doing this—that's crazy! And it only gets more so as it goes on.

"You have a new hand, artificial hand—that's amazing! Can touch it wow!" If they can add a rubber hand to my body that easily, I can only imagine what they could do with a little more effort in planning.