Best brains composed of conflicting modules.

[Carey N]

This is quite a striking piece of research - at the interface between psychology and evolution/optimality modelling. Jim: I think you'll really like it.

For anyone who wants to read the whole article but can't access PNAS: send me your e-mail address.


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Livnat, A. & Pippenger, N. (2006). An optimal brain can be composed of conflicting agents. PNAS 103(9): 3198-3202

Abstract:
Many behaviors have been attributed to internal conflict within the animal and human mind. However, internal conflict has not been reconciled with evolutionary principles, in that it appears maladaptive relative to a seamless decision-making process. We study this problem through a mathematical analysis of decision-making structures. We find that, under natural physiological limitations, an optimal decision-making system can involve "selfish" agents that are in conflict with one another, even though the system is designed for a single purpose. It follows that conflict can emerge within a collective even when natural selection acts on the level of the collective only.

[Margaret McGhee]

Carey, I think I've worked through this math-heavy paper well enough to get the gist of it. Thanks for spotting it and sending it along. I am still as surprised by the abstract as I was when I first read it in your post.

Especially, the statement about a decision-mechanism that resolves internal conflict, However, internal conflict has not been reconciled with evolutionary principles, in that it appears maladaptive relative to a seamless decision-making process. I have no idea what they mean by seamless here. But, I find its supposed maladaptive appearance to the authors surprising. What could be more adaptive?

I arrived at my view (SBCH) of competing emotional forces in the mind via my own path - and I therefore find it almost obvious. It emerged from my understanding of the human mind that was most influenced by Damasio and Susan Blackmore and then reinforced by LeDoux and Calvin. I didn't have to overcome the emotions of my own belief system as I had no clear idea of that mechanism when I started reading about this stuff - and I wasn't looking for one.

Now, I can feel those forces, that internal conflict, at work within me. I can see them at work in my cat's mind as her tail twitches while watching the birds in the feeder just outside my window. I observe them at work in others' minds when I read the posts to this forum.

It seems to me that life for all creatures is largely a process of resolving the conflicting forces that are part of complex environments full of both dangers and resources - using whatever decision-making mechanisms evolution has given us. It seems that mammalian emotions are evolution's proxies for those dangers and resources. They are reduced to a common substance for unconscious weighing in our brains and where, for some few animals, cognition sometimes provides an additional emotional input.

At the end of this paper the authors write Although we have provided a proof of principle to this effect, the various mechanisms by which such conflict could emerge call for further study and exploration. At this time I believe further exploration will reveal my SBCH (or something pretty close to it) as that mechanism.

If I had a criticism of the paper it would be that it seems focused on the notion of the resolution of conflicting forces. I would choose a more nuanced version of that. I'd say it is the resolution of forces from several brain regions, some of which may be in conflict and some of which may agree.

Even though conflict is often present in animal decisions, as observed in my cat's tail, an effective decision mechanism does not require that some of its inputs be in conflict in order for that mechanism to work well.

Margaret

[James Brody]

Carey:

Right you are! And thanks!

This idea was put well: "Organisms are extremely internally heterogeneous. Their states and motions are consequences of many intersecting causal pathways, and it is unusual that normal variation in any one of these pathways has a strong effect on the outcome. To be ill is precisely to be dominated by a single causal chain. To be obsessed by an idée fixe which motivates all one's actions, or to be convinced that all behavior on the part of others, without distinction, is hostile, is a form of mental illness...Indeed, we may define 'normality' as the condition in which no single pathway controls the organism." Lewontin, 2000, P. 93-94.

I also used the idea heavily in accounts of both bipolar disorder and ADHD.

Brody, J. (2001) Evolutionary recasting: ADHD, mania and its variants. Journal of Affective Disorders. 65: 197-215.

Brody, J. (2004) Bipolar disorder: self-interested networks, cycling, and their management. Chapter 2 in M. Brown (Ed.) Progress in Bipolar Disorder Research. Hauppage, NY: Nova Science Biomedical Series, pp. 33-64.

Brody, J. (2005) ADHD: Inhibition, Emergent Networks, and Maternal Investment. Chapter 2 in Michelle Larimer (Ed.) Attention Deficit Hyperactivity Disorder (ADHD) Research. Hauppage, NY: Nova Science Biomedical Series. pp.19-58.

Thanks!

JimB

[James Brody]

Carey,

I sent Adi Livnat an email and copies of the ADHD & Bipolar papers. He responded graciously and immediately with an offer to read my stuff and to send me copies of his future writing.

I expected him to approach the conflict problem through WD Hamilton and Albert Barabasi and Reka Albert but not so. He may gain from considering those sources. And I should gain: my earlier boast was that network theory, especially the Watts & Strogatz paper from nature, achieves clear explanations with small numbers. Livnat gives me another set of numbers.


Again, thanks for the lead...

JimB

References:

Albert, Reka & Barabasi, A-L (2002) Statistical mechanics of complex networks. Reviews of Modern Physics 74: 47-97.

Watts, D. & Strogatz, S. (1998) Collective dynamics of 'small-world' networks. Nature. 393: 440-442.

[Carey N]

Jim:

Glad to hear that you've struck up correspondence with Adi. I had the pleasure of meeting him a few months ago - he seemed like a great guy.

Looking forward to your thoughts on this new set of numbers . . .


-Carey

[Carey N]

. . . an effective decision mechanism does not require that some of its inputs be in conflict in order for that mechanism to work well.
Well . . . they did offer a formal proof, so it's not quite fair play to just state that they're wrong without confronting the details of the argument. I think it's important to note that they did not say that optimal decision-making machines must be composed of conflicting parts, but rather that they are composed of modules, each of which is responsible for one particular aspect of pursuing reproductive fitness. Sometimes these modules come into conflict with one another.

PS - how is your cat's tail an example of this? Isn't that just a muscle spasm as it tenses and readies itself for 'hunting mode'?

[James Brody]

Carey,

Well put!

My own scattered mind thought of Sherrinton's reciprocal inhibition, particlarly after scanning some language somewhere that hormones often occur in opposing pairs.

AND one property of a phase transition is that of an on-off switch! And adding connectivity within a phase transition slows decisions, an binary switch becomes analog, a dimmer switch. Inhibition emerges, "maybe" appears....

JB

[Margaret McGhee]

Hmmm. Did we read the same paper?

BTW - The title of the paper was not "Best brains composed of conflicting modules."

It was - An optimal brain can be composed of conflicting agents

I found nowhere where they said that . . . an effective decision mechanism does require that some of its components be in conflict in order for that mechanism to work well.

They said, Here we show that internal conflict can emerge even in the absence of gene-level selection. Namely, conflict can emerge within a collective even when natural selection acts on the level of the collective only. We contend that this phenomenon is a natural consequence of physiological limitations, and that internal conflict can emerge even in an optimal collective subject to those limitations

They did not say, Here we show that internal conflict will emerge even in the absence of gene-level selection. Namely, conflict will emerge within a collective even when natural selection acts on the level of the collective only. We contend that this phenomenon is a natural consequence of physiological limitations, and that internal conflict will emerge even in an optimal collective subject to those limitations.

Neither did I say they were wrong. Just that I would have approached the problem from a different angle and therefore would have stated my premise a little differently.

Regarding my cat's tail: A cat's tail indicates emotional arousal. When she sees the birds out there I suspect she is showing an anger emotion - or cat equivalent of that. The conflict is with her belief that the birds at the feeder are too difficult for her to catch since she tried it many times after we first moved into this house 5 years ago. That makes her angry. She shows the wide back and forth anger swish, not the tip of the tail stalking twitch.

Note that I placed the feeder where the birds would have every advantage.

My interpretation is that the inhibitory emotion from that belief was built up over several failed attempts until it finally became stronger than her hunting instinct. There was a period in between when she would stalk half-heartedly and give up easily.

I think humans also can get angry when we can not follow our instinctive behavior emotions.

She still hunts birds in the yard and bushes away from the feeder and is occasionally successful.

Here's a Wiki on Cat's Body language (http://en.wikipedia.org/wiki/Cat#Body_language)

Margaret

[Carey N]

BTW - The title of the paper was not "Best brains composed of conflicting modules."
I know what the title is, but altered the thread heading to make sure it drew attention. I also emphasized in my last post, which you did not seem to read entirely, that their stress was on the devotion of modules to separate tasks, which sometimes, but not always, come into conflict. Thanks for the condescension, though.


I would have approached the problem from a different angle and therefore would have stated my premise a little differently
You couched this as a criticism in the previous post . . .
If I had a criticism of the paper it would be that . . .
With no offense intended, you can't just say "I would have approached it differrently" without a nod to why exactly that is the case - i.e., by addressing the content of their argument and the reasons for which you think a different premise would be appropriate.

[Margaret McGhee]

Carey, I've been re-reading this exchange trying to find some value in re-arguing points already made - but I can't find any useful reason to do so. You accused me of saying the authors were wrong. I didn't. I agree with the paper. Even my seeming criticism was not a criticism. I said, "If I had a criticism of the paper . ." and then explained what it would be. I was nit picking - not finding fault.

You've now written several posts while not following up on a previous post where you committed to a clearer statement of your thoughts about discrimination.

Despite Fred's warnings I am not looking for a way to "win" something and prove you wrong. I want to hear your ideas on this. I am reading Pinker's ideas about this at this time and I'm having some trouble understanding where my ideas differ from his - although I feel they do in some way. I hoped your statement on this would help.

I would suggest that your reactionary approach is damagaing your ability to understand my statements and make clear statements of your own in this forum. If I disagree with you I will usually be very clear about how and why. You won't have to read any tea leaves to see it. Despite Fred's warnings you don't have to be looking for hidden traps in my posts.

I do enjoy competition in my life but I prefer to decide when and where I compete - and with whom. I see online forums as a place for ideas to compete - not personalities. I get irritated when people like Fred personalize the differences between opinions. The strong emotions raised by personal attacks make it very difficult to objectively focus on the emotionally weak content of scientific ideas. None of us here is a Mr. Spock.

Aside from Todd you were the only one here who seemed interested in the topics I am interested in and was willing to make some thoughtful posts on them. I now have to wonder how much of your posts are reaction to imagined traps and tricks - and how much are your actual ideas on a topic. This is not a tennis match for me.

I really appreciate Todd's well-reasoned posts here but I doubt if one unreactionary idea-laden post every 3 or 4 weeks is enough to keep me interested in this forum.

It already seems like I spend way more time considereng others' posts and my responses to them than anyone else here. After reading this last post from you it's really starting to feel like I'm wasting my time. Throw me a line if you have one to throw.

Margaret

[Carey N]

You've now written several posts while not following up on a previous post where you committed to a clearer statement of your thoughts about discrimination.
This is because I can quickly write responses in this thread, while it will take a while longer to sit and think about my next post on discrimination (I'm delaying my response out of consideration, rather than neglect - am bogged down with work at the moment and will be free again in less than 2 weeks).

I'm not trying to turn this into a competition - only asking you to flesh out some of your one-off comments. Judging from the language below . . .

Even though conflict is often present in animal decisions, as observed in my cat's tail, an effective decision mechanism does not require that some of its inputs be in conflict in order for that mechanism to work well.
. . . it seemed to me that you at least partially disagreed with the perspective or approach of the L&P paper (I understand that you don't think they're wrong, but the language suggested a concrete objection). I saw a potential point of discussion, and so asked for more justification.

I doubt I will be as composed or as erudite as Todd anytime in the near future (or ever), but I am very much interested in the issues at hand here.