What follows is the first installment - as well as the beginning of the two following articles (follow the title link to read the rest of the articles).
Why Did Consciousness Evolve, and How Can We Modify It?
I recently gave a talk at the Directors Guild of America as part of a panel on the “Science of Cyborgs” sponsored by the Science Entertainment Exchange. It was a fun time, and our moderators, Josh Clark and Chuck Bryant from the HowStuffWorks podcast, emceed the evening with just the right measure of humor and cultural insight. In my twelve minutes, I shared a theory of how consciousness evolved. My point was that if we understand the evolutionary basis of consciousness, maybe this will help us envision new ways our consciousness might evolve further in the future. That could be fun in terms of dreaming up new stories. I also believe that part of what inhibits us from taking effective action against long-term problems—like the global environmental crisis — may be found in the evolutionary origins of our ability to be aware.
This idea is so simple that I’m surprised I’ve not yet been able to find it already in circulation.
The idea is this: back in our watery days as fish, we lived in a medium that was inherently unfriendly to seeing things very far away. The technical way this is measured is the “attenuation length’’ of light through the medium. After light travels the attenuation length through a medium, about 63% of the light is blocked. The attenuation length of light in water is on the order of tens of meters. For a beast of a meter or two in length, which moves at a rate of about a body length or two per second, that’s a pretty short horizon of time and space. In just a few seconds, you’ll reach the edge of where you were able to see. If you’re down in the depths at all, or in less clear water, you may reach the edge of your perceptual horizon in about a second.
Think about that: life is coming at you at such a rate that every second unfolds a whole new tableau of potentially deadly threats, or prey you must grab in order to survive. Given such a scenario, we need to have highly reactive nervous systems, just like we revert to when we find ourselves driving in a fog or at night along a dark and winding road. The problem is that there was no respite from this fog. It was an unalterable fact of how light moves through water, relative to our own movement abilities and size.
But then, about 350 million years ago in the Devonian Period, animals like Tiktaalik started making their first tentative forays onto land. From a perceptual point of view, it was a whole new world. You can see things, roughly speaking, 10,000 times better. So, just by the simple act of poking their eyes out of the water, our ancestors went from the mala vista of a fog to a buena vista of a clear day, where they could survey things out for quite a considerable distance.
This puts the first such members of the “buena vista sensing club” into a very interesting position, from an evolutionary perspective. Think of the first animal that gains whatever mutation it might take to disconnect sensory input from motor output (before this point, their rapid linkage was necessary because of the need for reactivity to avoid becoming lunch). At this point, they can potentially survey multiple possible futures and pick the one most likely to lead to success. For example, rather than go straight for the gazelle and risk disclosing your position too soon, you may choose to stalk slowly along a line of bushes (wary that your future dinner is also seeing 10,000 times better than its watery ancestors) until you are much closer. Here’s an illustration of the two scenarios:
On the left, we have the situation when the distance we sense is close to the distance we will move in our reaction time (our reaction time is about 1/3 of a second; from that point to when we will stop is a bit longer– like those diagrams you see of stopping distance when driving at night show). There isn’t a whole lot of space to plan over. On the right, we can fit three very different plans to get to our prey: b1-b3, among others.
So what does this have to do with consciousness?
In 1992, psychologist Bruce Bridgeman wrote that “Consciousness is the operation of the plan-executing mechanism, enabling behavior to be driven by plans rather than immediate environmental contingencies.” No theory of consciousness is likely to account for all of its varied senses, but at least in terms of consciousness-as-operation-of-the-plan-executing-mechanism, due to some very simple “facts of light,” dwelling on land may have been a necessary condition for giving us the ability to survey the contents of our mind. “Buena vista consciousness,” for lack of a better term, might have been the first kind of consciousness that selection pressures could have brought about.
Given this picture of how a certain kind of consciousness came about, what are the knobs we might twiddle, either for the love of story making, or so that our transhumanist future selves might be conscious in a different way?
Let me borrow a moral quandary from philosopher James Rachels. Maybe you’re eating a sandwich right now. There is a child, far away, who is not, and who is about to die for lack of food. Surely, if that child were beside you, you would share your sandwich. But, then, what’s keeping you from sharing that sandwich anyway? The shipping costs? That’s easily avoided – we find someone on the ground who can buy the sandwich locally. If you think through the various possibilities, the only answer you eventually come to is that the starving child is too far removed from your state of awareness to really matter to you. Likewise with any number of a host of environmental devastations that are going on at this moment.
So, what if we massively expanded the blue space in the picture above, our sensorium? I don’t mean watch video of distant places (which surely is part of the way), but use artificial retina technology to directly pipe visual images from a disconnected place directly into your brain? Say, of the rain forest that is currently being destroyed so that an industrial meat producer in Peru can provide fast food chains in our country with low cost beef? This would be disruptive technology on a big scale.
Here’s another thought experiment: Notice that there is only one being in the pictures above.
Consciousness does seem to be for one being at a time. What if we reengineer things so that we see what others in our group see, or so that when you do something good, the entire group feels good, rather than just you? This kind of consciousness has been explored in science fiction (The Borg on TV), and in art (Mathieu Brand’s Ubiq). We even know mechanisms of how something like the hive mind of bees work, such as regulation of the division of labor through various genes and hormones.
Could something like this be the antidote to the endemic selfishness of Homo sapiens?
More details on the idea of buena vista consciousness can be found on pages 492-499 of this chapter I wrote in 2009.
UPDATE: A more technical paper describing how to quantify sensory and movement spaces is here.
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Why Did Consciousness Evolve, and How Can We Modify It, Pt. II: The Supremacy of Vision
I’m back after a hiatus of a few weeks to catch up on some stuff in the lab and the waning weeks of spring quarter teaching here at Northwestern. In my last post, I put forward an idea about why consciousness– defined in a narrow way as “contemplation of plans” (after Bridgeman)–evolved, and used this idea to suggest some ways we might improve our consciousness in the future through augmentation technology.
Here’s a quick review: Back in our watery days as fish (roughly, 350 million years ago) we were in an environment that was not friendly to sensing things far away. This is because of a hard fact about light in water, which is that our ability to see things at a far distance is drastically compromised by attenuation and scattering of light in water. A useful figure of merit is “attenuation length,” which in water is tens of meters for light, while in air it is tens of ten thousand meters. This is in perfectly clear water –add a bit of algae or other kinds of microorganisms and it goes down dramatically. Roughly speaking, vision in water is similar to driving a car in a fog. Since you’re not seeing very far out, the idea I’ve proposed goes, there is less of an advantage to planning over the space you can sense. On land, you can see a lot further out. Now, if a chance set of mutations gives you the ability to contemplate more than one possible future path through the space ahead, then that mutation is more likely to be selected for.
Over at Cosmic Variance, Sean Carroll wrote a great summary of my post. Between my original post and his, many insightful questions and problems were raised by thoughtful readers.
In the interest of both responding to your comments and encouraging more insightful feedback, I’ll have a couple of further posts on this idea that will explore some of the recurring themes that have cropped up in the comments.
Today, since many commenters raised doubts about my claim that vision on land was key – raising the long distance sensory capabilities of our sense of smell, and hearing, among other points – I thought I’d start with a review of why, among biological senses, only vision (and, to a more limited degree echolocation) is capable of giving access to the detail that could be necessary to having multiple future paths to plan over. Are the other types of sensing that you’ve raised as important as sight?
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Why Did Consciousness Evolve, and How Can We Modify It, Pt. III: Memory, Communication, and Perception
A fossilized trilobite with a bite mark.
Evolutionary neuroscientists suggest
that the brain only developed after
animals developed a taste for eating
animals. Pity the species of the planet
Vegetaria.
This is the third of a series of posts about the evolution of consciousness. In the first post, I laid out a basic theory that goes something like this: consciousness began to evolve about 350 million years ago, when we emerged from the water on to land. Why? By enabling vision to work over distances many times greater than in water, this move gave us the ability to perceive multiple futures. As a result, the ability to consciously plan ahead became important. In my last post, I detailed why long distance vision reigns supreme when it comes to planning (as opposed to other long distance senses such as hearing or sense of smell).
In this post, I want to make the argument more comprehensive. The crucial environmental condition for evolving neural structures to support planning is that there is an interlude— space to breathe— between perception and action. Without such a gap, only simple, fast, and direct transformations between sensory input and motor output can keep an organism safe from predators. But the long-range sensing abilities discussed in the last two posts are just one category of possibilities for such a gap to open: there are other fancy brain abilities unrelated to sensing that can also open this gap.
Here, I consider two such capabilities: memory and communication. An animal can plan to do something based on memory (“I remember good breakfast was always in this direction”), communication (“hey buddy, around the corner is a good place for lunch”), and, as discussed already, perception (“I see something tasty looking over there”). Let’s go through planning via memory and communication, and compare these to the perceptual route. Combined, the three different mechanisms are the very grist of the mill of consciousness-as-planning.
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