Comment Re:Huh? (Score 2) 140
What doesn't make sense to me is the synchronized motion part is really the trick here - that our brain will automatically figure out we're causing a sensation, even though the mechanics don't make sense or it's something we haven't experienced before.
I think I understand what they're trying to demonstrate, but the experiment is structured in a way that's not obvious. It starts from the idea that some people who have hallucinations of "ghosts" and other such things have damage in their brain, in an area that coordinates different sensations to determine cause. So it's like, if you were to flick yourself in the leg, you would feel one hand flicking, hear a brief "thud" noise from the impact, and feel an impact on your leg, and there's a part of your brain that would somehow collect all those things and go, "These were all the same event. Nothing to worry about. Nothing to be concerned about."
So when they're synchronizing the motion that people are making to the motion of the robot, they're allowing that part of the brain to function normally. The test subject pokes their finger forward, and they get poked in the back. Their brain goes, "Oh, you did this to yourself somehow. Nothing to worry about."
But when they have the robot act on a delay, they're simulating what it would be like if that part of your brain was damaged. You're still in control of the robot, and so you're still poking yourself, but because it's on a delay, that part of your brain that coordinates those things goes, "Whoa, you did *not* do that. Something else is going on here." It's not that they literally believe there's a ghost poking them, but the point is that the experience is disturbing.
And because it is disturbing in a way that's similar to "ghost" or "alien" experiences that people have when that part of their brain is damaged, these researchers think that it explains what's going on with those experiences/hallucinations. The brain is failing to coordinate sensations, and so the brain is attributing experiences of motion/sensation to an alien force of some kind. ("alien force" not necessarily meaning space-aliens, but just "foreign to oneself")