Sunday, March 22, 2009

Emergence 6: Learning from the Structure of our Brains

In this series on emergence, the core dilemma that, appropriately enough, has emerged from this inquiry is that science does not have an adequate explanation for how emergence occurs--specifically, how the theorized phenomenon of "strong emergence" works.  This post will address this problem by looking at what gives rise to, arguably, the clearest example of strong emergence:  human consciousness as an emergent property of the brain.

Is human consciousness strongly emergent?  This question first requires defining "strongly emergent," which I will define as:  a phenomenon that is supervenient on a substructure but that is fundamentally irreducible to laws governing that substructure and which is capable of exerting downward causation on that substructure.  That's a mouthful, and for those who haven't read the second post in this series, "Weak vs. Strong Emergence," it may be worth the five minutes to do so.  That said, it appears that human consciousness meets there criteria:  despite decades of intense investigation, science has so far been unable to demonstrate how consciousness is reducible to the biological structure of the brain--or even to come up with seriously considered theories of how this might be so; and consciousness is clearly capable of exerting downward causation on the structure of the brain--everything from suicide and drug use (which affects the biochemical makeup and functioning of the brain) to more subtle effects such as emotion (changing blood flow patterns) and meditation (which, over time, evidence suggests can fundamentally re-wire certain brain hardware).

Contrast strongly emergent human consciousness with "weak" emergence--the many social and natural phenomena that, while being theoretically reducible to the laws governing individual components, and capable of modeling and simulation, are practically too complex to understand in any way other than by modeling and simulation.  The human brain/consciousness pairing is particularly intriguing in the study of strong emergence because 1) despite many, many examples of "emergence," the consciousness is the only clear example of "strong" emergence that I'm aware of; 2) it is exceptionally well studied; and 3) it is something of direct interest and access to all of us.

What characteristics of the brain appear to facilitate strong emergence?  In "Social Emergence," Keith Sawyer notes that:

Complexity theorists have discovered that emergence is more likely to be found in systems in which (1) many components interact in densely connected networks, (2) global system functions cannot be localized to any one subset of components but rather are distributed throughout the entire system, (3) the overall system cannot be decomposed into subsystems and these into smaller sub-subsystems in any meaningful fashion, (4) and the components interact using a complex and sophisticated language.

P. 4-5.  The human brain arguably exhibits all of these attributes, but is particularly notable for the first attribute--many components interact in densely connected networks.  Another notable sociologist and systems theorist, Talcot Parsons, noted that decomposable systems--that is, systems comprised of functional modules that only interact at specific points and in specific ways--are far less likely to exhibit emergence than are non-decomposable systems.  While neurology and psychology suggests that certain brain functions are localizable to what are arguably functional modules, the phenomenon of consciousness (or, as some suggest, related set of phenomena) does not seem to be so localizable.

I suggest that this notion of "localizable" is better viewed as a matter of "non-hierarchal."  Where components are organized into hierarchal structures, they are almost by default localizable, and this hierarchal nature may provide insights as to why this matters--in hierarchy, the "base of the pyramid" does not communicate freely and frequently with the base of other pyramids, but rather this communication is channeled and mediated through the hierarchal structure itself.

I also think that pattern of connections between neurons in the brain is critical--rather than a "lattice" or "crystal" structure where neurons are routinely connected to only those physically proximate neurons, the brains neurons tend make relatively distant and non-uniform patterns of connection.  I've discussed this type of connectivity elsewhere as an optimal configuration of "small worlds networks," and I think it plays an important role in consciousness because it amplifies the connective and communicative power of already dense networks.

Based on this foundation, it seems that the key structural attribute of the human brain is dense networks of weak (more than just physically proximate) connections with very little or no hierarchal structure noticeable in the operation of individual neurons or their pattern of connectivity.  Out of this structure, human consciousness emerges, apparently irreducible to the action of the neurons themselves, yet able to influence the structure of those neurons (both on a micro-level of memories, personalities, etc., and on a macro-level of biofeedback in various forms).

Of course, without a clear understanding of how and why strong emergence occurs (something that, by the very nature of a phenomenon being strongly emergent may be unknowable?), we are left with the leap from "these properties are present in a system that produces strong emergence" to "therefore the presence of these properties in a system causes strongly emergent phenomena."  While we should recognize this logical leap and not attempt to sweep it under the rug, we would do well to also recognize that this is very much the same leap that we always take when reaching conclusions as to causation.  As Scottish philosopher David Hume pointed out plainly, at some point we always make the unsupported leap from (simplified) "this happens after that happened" to "this happens because that happened."

With only one good example to work with (human brain --> consciousness), I'm not yet ready to state that it is the structure of the brain that creates consciousness, or the corollary (and what I'm really interested in) that replicating these structural attributes elsewhere will similarly produce strongly emergent phenomena supervenient on that structure.  This is, however, my working hypothesis--I'd love to hear thoughts on other examples that tend to support or refute it.  In the next post, I will conclude this series (at least for now) with the application of this hypothesis to building a sustainable social structure.

Readers may also find my litigation checklist of interest.

9 comments:

ryan said...

great stuff, Jeff.

"science has so far been unable to demonstrate how consciousness is reducible to the biological structure of the brain--or even to come up with seriously considered theories of how this might be so."

VS Ramachandran has some pretty good leads (and he seems to buy Jaynes' "Origins" theory).

VS - The neurons that shaped civilization-http://www.youtube.com/watch?v=t0pwKzTRG5E

Check out his book "A brief tour of human consciou5ness" when you get the chance - he cites some really interesting evidence from clinical studies of bizarre neurological syndromes to support his ideas on consciousness. certainly neither he nor anyone else has figured consciousness out... but then if someone/some group were to reflectively comprehend immediate experience and awareness as well as communicate this knowledge in a means that was both analytically accurate and emotively compelling, wouldn't that alone radically alter the consciousness of all those exposed to the explanation? in other words, if our current level of consciousness is able to be "grasped," would this allow for strong emergence of another level of reflective awareness?

both spiritual traditions as well as scientific theories of mind/matter/consciousness (neutral monism) share certain themes... the comedian bill hicks has a great bit on this in relation to drug experience - “Today a young man on acid realized that all matter is merely energy condensed to a slow vibration, that we are all one consciousness experiencing itself subjectively, there is no such thing as death, life is only a dream, and we are the imagination of ourselves. Heres Tom with the Weather."
Bill Hicks - Positive Drug Story - http://www.youtube.com/watch?v=vX1CvW38cHA

Al Eggen said...

Jeff, very interesting!

Thought of some possible examples - though I'm not at all sure they fit.

take a degraded ecosystem in the NE US, thin, eroded soils, not a lot of life. What life there is seems to have the kind of structure you're talking about. Leave it alone for a few centuries and you now find an equilibrium forest with deep soils and a lot of diverse, loosely related life forms. Stages with even more diversity may have come before.

Another possible example is in early evolution. You start with an atmosphere that's more hydrocarbon than oxygen and some anaerobic microbes as early life forms. A few billion years later you have an atmosphere with enough oxygen to support the massive expansion of life forms that now exist.

Natural selection? What advantage is there for a methane eater to evolve into something that can generate oxygen? What is there about evolution that drives it in the direction of more complexity and more diversity? Is it some form of emergence?

Some very difficult questions, possibly unanswerable. However, I agree that there is a good chance we can learn some very useful and insightful approaches to the organization of resilient communities from these studies.

Thanks for your work,
Al

ryan said...

Social insects serve as another model for studying strong emergence in biological systems, with the added benefit of avoiding the effect of the observer attempting to objectively comprehend emergence in his own consciousness.

How about strong emergence in human culture at present? Certainly the advent and popularity of the internet, youtube, facebook, etc are leading to novel social connectivity and movements…

I see strong emergent phenomena in the global solidarity actions of the anarchist/social-environmental justice movement. The immediate attacks and direct actions in solidarity with the shooting death of the Greek anarchist Alexandros Grigoropoulos in 2008 were very impressive. See Alexandros Grigoropoulos-Violence EVERYWHERE!! Greece 2008 - http://www.youtube.com/watch?v=Gs1JIwbPm_o See also “international response and demonstrations abroad” - http://en.wikipedia.org/wiki/2008_Greek_riots

Within the anarchist online communities there has been mention of “autopoietic insurgency” or “emergent insurgency” to refer to the global solidarity movements/direct actions. Just as ants use chemical stigmergy to signal and coordinate action it seems the anarchists have adopted more blunt cues: banners, graffiti and slogans read “solidarity means attack,””global riot,” “no war but class war” and so on. Youtube videos of “riot porn” inspire and incite anarchist to join in attacks. The drivers of violent (or “counter-violent” depending on your view of the inherent violence of the state…) global insurrection are, of course, much more complex, relying on the background behavioral cues and patterning the collective forces of socio-cultural evolution…

Anonymous said...

Natural selection? What advantage is there for a methane eater to evolve into something that can generate oxygen? What is there about evolution that drives it in the direction of more complexity and more diversity? Is it some form of emergence?

Perhaps the answer is information. Overall the amount of information in the genome increases with time, and emergence is a direct result of increasing complexity.

Anonymous said...

Mr. Vail, is your essay "a theory of power" available online or must it be purchased?

Anonymous said...

One thing that seems implicit in the emergence discussion is the assumption that the current particle model of physics is the correct model for the nature of reality.

Personally I find it interesting that other cultures, particularly eastern spirituality tend to view ultimate reality from the perspective of non-duality. So what if our assumption that natures building blocks are atoms is incorrect?

I think that it would be interesting to try to reconcile current physical models of the universe with monoism as an underlying tenet, as opposed to dual particle nature. In this view we would probable not be asking the question of what causes consciousness but instead assume it to be the indivisible foundational feature of all reality.

Jeff Vail said...

Anon.:

"A Theory of Power" is still online (start with Chapter 1 at http://www.jeffvail.net/2004/10/theory-of-power-chapter-1.html). However, with the recent forced "upgrade" to Google's hosing (as opposed to ftp hosting at my own domain), the links to the .pdf version are broken at the moment. I'll get it back up online shortly (and make a quick post to let people know that the links are working again). This also applies to other .pdf files, such as "The New Map" and "Private Law of War." Sorry for the delay...

Anonymous said...

I tried the link you provided for theory of power and it indicated it was broken? I'll check back later.

Jeff Vail said...

Try this link:

A Theory of Power

It's working for me, but hopefully I'll get the .pdf up shortly...