Just because our human bodies have these particular hands, it doesn’t necessarily follow that they are the only kinds of hands our brains could ever be good at using.
While it is true that our brain’s parietal lobe provides massive computational machinery for assisting in manipulating objects with our hands and fingers, it is not necessarily true that the parietal lobe evolved only for these particular human hands, with their five jointed digits and single opposable thumb.
Evolution is parsimonious, since it proceeds via a kind of haphazard hill-climbing algorithm. It’s much more economical (and reachable through the random walk of evolutionary steps) for a brain to encode a set of general procedures for individual learning, than to hard-wire into our neurons all the particulars of specific grasps and gestures.
We see something similar in spoken language. Human children have evolved to learn any language that follows a common set of procedural rules, not any one specific language such as Japanese or Serbo-Croation.
This loose coupling suggests an intriguing possibility: As our technology continues to advance to the point where we will be able to have the sensation of physical manipulation — as well as gestural communication with each other — using whatever bodies we choose, perhaps we will evolve those virtual bodies in various ways.
It might be more useful to have tentacular fingers, or two thumbs on each hand, or something even more radically different. In a sense this question comes down to understanding the functional set of learnable procedures encoded in our parietal lobe, since any modification to our virtual bodies that is not supported by our brain’s hardware will not gain wide acceptance.
There is certainly precedent for looking at such things. In particular, something analogous has happened throughout human history in the evolution of musical instruments. The variety of extant musical instruments is vast, yet no instrument will survive from one generation to the next unless our brains can control our hands when playing that instrument. In a way, the corpus of popular musical instruments serves as a kind of functional roadmap of our brain’s parietal lobe.
If, after mastering the underlying technology, we manage to “physically” evolve the virtual bodies with which we will communicate in cyberspace, that will lead to all sorts of fascinating questions. For example, I wonder what it will mean for the future evolution of musical instruments.
Why would musical instruments necessarily be controlled by “hands” (or whatever their equivalent is) in the future that you are imagining? Why wouldn’t the brain control virtual instruments directly, the way it controls virtual bodies? (I don’t really know what is or isn’t possible in this future that you’re imagining. Which movie are we in… Avatar? The Matrix? 🙂 )
The general idea is that the parietal lobe of the brain has some sort of parameters, which have been set by the evolutionary path of our species. So I’m looking at our brain’s current biological state of evolution as a fixed point. Around that fixed point we can change whatever we want.
If we are trying to make best use of that brain capacity, then one way to state my fundamental hypothesis is that it’s likely to be a more fruitful direction — assuming the technology will advance to the point where any of this is possible — to evolve some sort of general manipulation capability, the equivalent of more capable hands, rather than try to connect our brains directly to, say, special purpose one-off musical instruments.
By creating “future hands” as a hands-on staging ground for innovation, we will be better able to use our powerful intuitions about dextrous manipulation to experiment and evolve and optimize all sorts of instruments.
I’m not so sure I’m talking about either of those two movies. Both of them are attempts to simulate our brain/body interaction pretty much in its current state, perhaps with minor variations (like being ten feet tall and blue, or looking really cool in long coats and sunglasses).
How do you imagine that we will hook up these virtual bodies, or physical modifications, to our brains?
In the near term, we can puppeteer them with our existing bodies and hands. But we will get vivid and perceptually rich visual, audio and touch feedback as though we have the alternate body.
This may be somewhat tangential, but have you ever heard Zoe Keating’s music (http://www.zoekeating.com/bio.html)? She is a cellist/composer who uses her cello, along with a foot-controlled laptop, to create much more intricate, multi-layered music than one could create with a cello alone. I’ve seen her perform live (with the Radio Lab show when they visited Google), and she’s quite impressive. I don’t completely understand the technology she uses, but it involves sampling the music from her cello with the laptop (in real time) and then looping the sample as she continues to play. This discussion made me think of her because, while she’s not directly employing new sensory or motor controls of a “virtual body” to an instrument, in some sense she has created a new instrument with her cello + laptop and her brain has adjusted to figure out how to play it (when to create a new loop and how to set it up to work in with the music that follows).
Getting back to your original point, I’m finding it hard to see how we can get access to the general model in the parietal lobe while we are still controlling things with our current physical hands and bodies. I guess researchers often learn about how the brain functions by studying deficits (the effects of brain injury), and by looking at imagery (e.g., fMRIs) taken while performing specific tasks. What you’re suggesting sounds more like augmentation than like a deficit. I wonder how we would learn about that.
Zoe Keating’s music is cool!!!
Here’s a scenario: We interpret the movement of your existing hand differently, as though you had two opposable thumbs on that hand. When you bend your little finger, the visual and haptic feedback you get, in this augmented environment, is exactly what you would get if it were a true opposable thumb. Even the physics of the objects you appear to manipulate support this version of reality.
One research question would be whether you could fundamentally do things in that reality that you simply cannot do in this one. It would largely depend on whether your parietal lobe can remap, based on the sensory feedback we’re giving it, to work with a hand that has two opposable thumbs.
That sounds like a mind-blowing experiment! Let me know when you’ve got it prototyped in your lab 🙂
It occurs to me that there should be some precedent for this kind of experimentation in the area of waldoes (the robotic manipulators, not the skinny guy who plays hide and seek in crowded scenes). I looked up waldo in Wikipedia and learned that the term comes from a Heinlein short story (http://en.wikipedia.org/wiki/Waldo_(short_story)) about a man who is born very weak but brilliant, who creates a powerful robotically controlled hand for himself. Now I’m curious to read the story.
I love Waldo!! It’s usually sold as two novels in one volume, together with Magic Incorporated.
Not only has Waldo been one of my favorite stories since I was in my early teens, but I suspect it had a lot to do with the professional choices I’ve made — particularly the way it celebrates the sheer power of invention.
There is so much in there to think about. To cite just one example, Waldo (the main character) doesn’t just create one tele-operated pair of hands — he creates a whole series of them, from microscopic all the way up to gigantic. This allows him to use his hands for everything from micro-surgery to building a house.
Cool!! I look forward to reading it! The Palo Alto Library has it and I tried to go there today, but it was closed for Labor Day.
I didn’t really start reading science fiction until college. I missed the whole teenage Heinlein phase.
BTW, the book that I put on hold at the library is called “Three by Heinlein: The puppet masters, Waldo, Magic, inc.”. There are those puppets again 😉
Yes, I’ve read that edition too. Puppet Masters is a wonderfully creepy story. You’ll recognize a lot of stories that have stolen from it.