You’ve probably heard about the rat-brain network by now — it showed up in the popsci threads back at the end of February, provoking breathless comparisons with Vulcan mind melds and The Matrix. And I gotta say, the coverage certainly sucked me in: an actual (albeit rudimentary) network of brains, linked together to solve problems? Hive-Mind stuff; Mind-Hive stuff. Something very much like it shows up in Echopraxia. It makes a cameo in “Giants”. The talk I gave at last year’s SpecFic Colloquium got into it big-time. Right up my alley.
Then you read the actual research paper and, well… not so much.
This is how they sell it; this, technically, is how it was. The brains of two rats, each connected to the other by an array of microelectrodes implanted in the motor cortex. One of them is presented with a stimulus; the other, with the means to act on that stimulus1. If the second rat reacts correctly to the stimulus the first one perceives, both get a reward. Rat #2 — gifted with no clues or insights save those piped directly from the brain of Rat #1 — reacts correctly 70% of the time, far more often than the 50% hit rate that random chance would serve up.
Ergo, the rats’ brains are in direct communication via an electronic network. Technologicaly-mediated telepathy. Technepathy.
There are the rudiments of a B2B interface here, certainly. Motor cortices and embedded electrode microarrays. A computer that mediates signal transmission from one to the other. Options presented, choices made, a reward for pressing the right lever. The way the Results are worded you really get a sense of linked minds, that the signals received by decoder-rat were pretty much the signals generated by the motor cortex of the encoder (“The primary factor that influenced the decoder rat’s performance was the quality of spatial information extracted from the encoder rat’s M1,” Pais-Vieira et al tell us. “The performance was high if the chosen neuronal ensemble accurately encoded left versus right presses”.) You imagine the array reading the motor commands off the very cortex, sending them through the internet, inserting them into the recipient’s motor control system where — possessed by an alien command planted in her brain — the little rodent feels an irresistible urge to move her paw just so.
Only when you move on to the Methods (Yes, “Methods” come after the “Results” in this paper for some reason), do you discover: oh, wait. The recipient was trained beforehand to push one lever or the other, depending on the incoming stimulus. And the stimulus wasn’t a motor command copied-and-pasted from one brain to the other, it was an arbitrary signal sent by the computer after the computer had decoded the sender-rat’s neural activity. It’s the difference between experiencing an orgasm and watching a tiny figure on a faraway hill spell out oh-god-oh-god-oh-god-yes using signal flags.
In other words, this is a brain dyad only in the most trivial sense. There’s no real meeting of the minds here, no sensory input or motor commands flitting between cortices in native neuro-ratspeak. Sure, the recipient must be feeling something; but whatever that is, it’s not the vicarious feel of walls against whiskers or the urge to move a muscle. It’s more itch than insight; the little guy was just trained beforehand to push one lever in response to Itch X, and another in response to Itch Y. For all the telepathy involved, he might as well have reacted to a blinking LED.
I admit I’m curious as to what that itch actually felt like, mind you. After all, the electrodes were embedded in motor wiring, not sensory; I’m a bit surprised that Pais-Vieira’s decoders felt anything at all (I’d have expected some kind of uncontrollable muscle tremor). And this is the standard approach used by all those wired-up primates who’ve been making news by controlling robot and/or virtual limbs with their minds. You don’t move that thing on the screen by actually sending a motor command down your arm; you just kinda concentrate, and the computer takes those arbitrary brainwaves and interprets them as left or right. Somewhere out there, someone might have trained an on-screen avatar to jump whenever she thinks the first six notes of “Aqualung”. It’s all pretty cool.
Which is not to say that I find the idea of brain-to-brain networks ludicrous in principle. I’m actually a bit scared by them. Everybody knows what happens when you split a brain down the middle, force the hemispheres to resort to the dial-up speeds of the hypothalamus instead of the broadband pipe of the corpus callosum: two distinct personalities emerge in the space where one had been before. Fewer people, I suspect, know that it works the other way around; when isolated hemispheres are reconnected (when an anesthetized hemisphere wakes back up, for example), the persona manifested by the lone hemisphere gets swallowed into the greater whole. I see no reason why that wouldn’t scale up. If you could build a fat enough pipe between two intact brains — an electronic corpus callosum, as it were — and if you could keep latency down to below the few-hundred milliseconds that seems necessary for coherent self-identity — would the result be two linked minds, or a single distributed one? Would the parts retain their identity, or would consciousness expand to fill the space available? If you joined such a network, would you retain any more autonomy, any more sense of self, than your parietal lobe enjoys now?
I feel a story coming on: a few decades from now, a glitch in the iMind servers inadvertently surpasses that magic bandency threshold and a few million streaming subscribers meld for a few minutes. But the subsequent class-action lawsuit fails when Apple argues that none of the affected individuals have standing to bring the case, since none of them actually existed as individuals during the alleged events. Maybe it even countersues on behalf of that vast and ephemeral mind who took their place, only to be torn apart and murdered after a measly ten minutes of life.
I bet I could keep it short enough to fit onto the back page of Nature. Still need a punchline, though.
1 Die-hard fans will remember that this is pretty much the same experimental protocol that the crew of the Theseus inflicted on the captive Scramblers in Blindsight, albeit without the active torture component.