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17:12

My Dinner with Ramez: or, The Identity Landscape.

A week or two ago— just before all the stuff with Kevin went down— I hung out with Ramez Naam for an evening. (If you know who I am you certainly know who he is; his Nexus trilogy burned across the charts in a way I can only dream of.) We snarfed. We drank. We covered all manner of topics from climate change to networked intelligence, from self-promotion to the Koch Brothers. It gave me the same kind of rush I used to take for granted in grad school; ideas and paradigms and competing hypotheses dueling over beers, a kind of good-natured head-butting where ideas trump ideology. I also have Mez to thank for kicking loose in my brain perhaps the first semi-original idea I’ve had in months.

It has to do with continuity of the self.

We all know that the mere act of existing changes us. Every poster you read, every song you hear, every fart you smell rewires the brain a little. Every perception of every qualium literally changes your mind.

How many of those changes does it take to turn you into a qualitatively different person?

It’s a question that’s always nagged at me. I certainly feel like I’m the same person I was when I was eighteen— my tastes may have changed, I may have learned a bit more restraint, my priorities and opinions may have mutated and metastasized— but that all just feels like tweaking the interface. Swapping out old peripherals for new. Deep in my skull the CPU feels the same it always has, even if it’s layered a few more social skills onto the GUI. All my experiences, such as they are, don’t seem to have altered my basic perceptions and attitudes very much. To the extent that I’ve been reprogrammed, those inputs haven’t reprogrammed me as much as, say, a tamping iron through the frontal lobe. Or even the less-traumatic— but no less remarkable— messianism that sometimes results from epilepsy.

From split-brain studies to multicore manifestations, there seem to be cases in which one person can abruptly change into another. Is this truly a more radical transformation than the changes we all go through in the course of our lives, or does it simply seem that way because it happens instantaneously? How much of a difference is enough? How many arguments and antiabortion posters and life-threatening situations do you have to experience before you’ve turned into someone else, a different being lurking behind the same name and face?

It may seem like a fatuous question, like arguing over a series of indistinguishably different shades of paint; a biologist friend of mine likened it to trying to define the term species (how many genetic differences are enough? How many incompatible traits?). Maybe it’s a fool’s errand to try and make a step function out of something that’s intrinsically continuous— and yet, dammit, there are these radical toggle-shifts between personae, even as there are innumerable little edits and rewires that alter a stable identity from second to second. Kevin can switch from relative lucidity to literally thinking that he and his cat are the only non-illusory beings in the universe, and that they are living on the surface of the Sun. Surely there’s got to be a model that encompasses both?

The question came up while Ramez and I were talking about uploaded consciousness— something to do with how much fidelity the upload has to share with the meat in order to be considered the same individual— and faded again into the last round as the subject turned to climate change. Ramez is intrinsically more optimistic than I about our prospects in that regard (although not so optimistic as his twitter feed might lead you to believe); I was trying to change his mind by reconstructing what I remembered from grad school about fold catastrophes:

Good luck climbing back up the damn thing.

Good luck climbing back up the damn thing.

It’s like all the possible system states form this line, I said. Imagine that the system itself is a ball bearing rolling along it. A fold catastrophe is what happens when the line twists into a kind of overhang. The system is perfectly stable until it reaches the edge of that cliff; then it drops down to a whole new equilibrium. It only took a little push in one direction to go over the edge, but you can’t get back to your original state by simply expending the same amount of energy in the opposite direction; it takes way more energy to get back up the cliff than it did to fall off it in the first place. So the system stabilizes at a new, lower, more fucked-up equilibrium, and it’s pretty much stuck there.

We were talking about climate change, but the residue of our previous foray into neuroscience was still rattling around in my mind. And over our third beers, there at the Bedford Academy, those two subjects just kinda clicked, two bubbles in a Venn Diagram overlapping at just the right spot—

What if Identity is like a fitness landscape?

Forget the simplistic 2D line I invoked for fold catastrophes; that’s just one axis of a complex system. And forget any N-dimensional landscape that could hope to encompass fitness landscapes in all their glory; our dumb ape brains wouldn’t be able to grasp those figures even if there was some way of rendering them on the screen. Settle instead for a 3D surface where fitness scales to altitude and the X and Y axes represent any two variables you’d care to consider. Grab that ball-bearing from the previous exercise; once again, that represents the actual system at any given time.

stable-unstable-graphThere are a lot of equilibria on such landscapes, places where the ball-bearing— left to itself— would rest motionless forever. Some of them are stable: little pockets in the landscape the system will roll back to even if perturbed. Once achieved, it takes a lot to keep it away from those coordinates. Other equilibria are unstable. Think of the ball-bearing balancing atop a peak: it won’t move if you don’t disturb it, but you could knock the little fucker from its perch with a sneeze— and once displaced, it’s unlikely to ever attain those heights again. And then you’ve got the neutral equilibria: the flat bits, where the system can be pushed off-center with relatively little force but can be pushed back again just as easily.

Everything else on the landscape is slope, transition zone. The system can pass through those states, but always on its way somewhere else. It can never come to rest there.

Just sign off on the concept, and we'll fill in all the fiddly little details later. Graphic grabbed from Hayashi et al 2006, and put to completely inappropriate use in a totally different context.

Just sign off on the concept, and we’ll fill in all the fiddly little details later. Graphic grabbed from Hayashi et al 2006, stapled together with some other stuff, and and put to completely inappropriate use in a totally different context.

You see where I’m going with this, right? You saw it about three paragraphs ago. I’m not talking about landscapes of genetic or ecological fitness at all; I’m talking about neurological system states.

Every equilibrium is a Self, an identity. The slopes between them contain camping trips, love affairs, concerts— all the day-to-day experiences that incrementally change the system as it moves through phase space, but not enough to change the identity at its heart. No one of these infinite-divisible coordinate shifts is enough to turn one Self into another; for that, you have to move between equilibria. At the same time, you can’t move from one equilibrium to another without passing through a myriad of those intermediate states.

The vital variable, therefore, is how steep the slope is between selves.

The Sybils and Phineas Gages and Kevins of the world, rolling around their steep hills and valleys, may go through more transitional states in minutes than the average neurotypical would experience in decades, maybe a whole adult life. The trip covers the same straight-line distance; its just that most of that distance is measured vertically, along the Z axis. People with a secure, stable sense of self will exist in topographic depressions, stable equilibria the ball-bearing will roll back to after all but the strongest perturbations. People on the verge of a psychotic break might be perched atop a mountain somewhere.

(For the purposes of this post it doesn’t really matter what the axes measure—any relevant metrics of brain activity will do—  since any useful quantitative model is likely to have way more than three dimensions anyway. This is just an illustration of the general principle.)

It’s not a perfect model. What about the plains, for example, the realm of the neutral equilibria? If you define each Self as an equilibrium, then the plains would contain myriad Selves existing cheek-to-jowl, technically separate “people” even though they may only differ in whether they think that “Spock’s Brain” was a worse episode than “Plato’s Stepchildren”. On the flatlands, you could change back and forth from one person to another a dozen times during the course of a single Star Trek episode. This doesn’t leave us much better off than we were before.

Offhand I can think of two ways to deal with this: either exclude 0-slope terrain from the model as a starting condition (thus eliminating neutral equilibria); or weight the value of the Z-axis in such a way that the separation in the X-Y plane doesn’t matter nearly as much as separation in altitude. In the latter case, the system could change from one self to another either by moving halfway across the world horizontally (the equivalent of gradually becoming a different person as you accumulate experience throughout your life); or by only moving a step or two the left in XY space while moving radically along the Z axis (those identities that shift instantly, those cases where it seems as though there are two people in the same head).

I don’t know. Maybe it’s just a useful metaphor (then again, ecological fitness landscapes are basically metaphors anyway); maybe it’s a framework for something you could plug real numbers into. Or maybe it’s just a deep dumb dive down a wrong alley. But I’ve been thinking about such things ever since Kevin arrived, and vanished, and reappeared like a scarecrow in our back yard (yeah, the story continues— another post, maybe). And I can’t help but think that this insight, right or wrong, would never have occurred to me as I sat here typing and scrolling and reading by myself with my cats at my side; it took a free-wheeling conversation with a dude I’d just met for me to knock those pieces together in new ways. I’ve lost count of the cool ideas that have emerged not from my brain, not from someone else’s, but from the sparks that fly when two or more brains get together in meatspace and real time. I’ve yet to experience an online platform that works as well as the neighborhood pub.

It’s a bit ironic, though, isn’t it?

Almost two thousand words of free-wheeling cognitive speculation, of new conceptual models of neuroidentity— and it all boils down to the conclusion that I need to go out more often to kill my own brain cells.

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