How many hands have you got?
Individual results may vary, but for most people, the answer is 2. You probably didn’t have to check the ends of your arms to come up with that answer – your brain already knew it. And your brain is always right, right?
Yesterday, Beth-Ann sent a link to an interesting New York Times blog about an experiment conducted in Sweden that has provided a fresh variation on the “traditional rubber hand illusion.” I admit I did not know rubber hand illusions had a tradition.
I guess the world is full of ancient and exotic rituals.
In the “traditional” rubber hand illusion, a subject places one hand on the table while their opposite hand is hidden. A rubber hand is then put on the table in front of the subject in the spot where the hidden hand would have been, had they not withheld it. An experimenter then strokes both the hidden real hand and the exposed fake hand with a brush, and before long the subject begins to associate this sensation with the false hand they can see, rather than the real hand, which they cannot.
That’s sufficiently weird, but some people can’t stop messing with tradition.
In this new wrinkle, the real hand and the rubber hand sit side by side on the table in front of the subject. A sheet is draped over the arm so it’s not clear which appendage is actually connected to the body. As in the “traditional” illusion, both hands are stroked with a brush, and an unexpected thing happens. The subject takes ownership of both hands, feels sensations in both hands, and flinches when both hands are threatened with a knife.
It took me a while to understand the importance of this: Apparently our brains are big gullible goofballs.
If you’ve lived your entire life with only one right hand and then all it takes to confound you on that topic is a rubber duplicate, a paint brush and a sheet, that doesn’t speak very well for your innate sense of the world. How could your brain do this, the traitor? Accepting another, squishier right arm as your own, even though your perfectly good and historically loyal right arm is sitting right there in front of you? Scoundrel!
Suddenly it’s easier to understand the fruitless chase for WMD in Iraq and the epidemic of older men running off with younger, bouncier women. Brains don’t need a lot of convincing to buy into an obviously ludicrous idea. The elastic brain re-configures its wiring to create a reality that matches what it sees. Or what it thinks it sees. The internal dialog must go something like this:
“That pert young co-ed finds a paunchy, bald, wrinkled up prune of a U.S. Senator like me far more attractive than handsome, fit, energetic men her own age? Love is funny that way, I guess!”
“Hmm. It appears I have inexplicably grown a second right hand. Finally, a use for that orphaned winter glove! No wonder she loves me! She’s really into three handed men!”
Amazing. Science has proven what I already know. Brains are easily duped.
Or did I simply WANT to believe that?




