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Unread May 31st, 2006, 01:21 AM
Margaret McGhee Margaret McGhee is offline
Join Date: Jan 2006
Posts: 271
Default Re: Damasios: Professors of Creativity

Hi Todd, Your posts are very information rich and they take some time to digest - but I think I'm ready to partially reply to this one. Just to be sure you understand my purpose, I'm not interested in agreement as much as a chance to explore your (and others') view of these things. My replies are the impressions I get from seeing your view through my own window. I don't have anything to prove here - but I suspect you knew that.

Seattle Sushi I used to travel a lot and have looked for good Sushi in most US major cities. Now that I've lived in the Seattle area for a while, Nikko's, now in the ground floor of the Westin Hotel downtown is still my favorite.

Limbic system Again, my interest is in the nature of the inputs and the algorithm more than locus. But I like to think about location to be sure that what I envision functionally could exist in that physical space and in accord with what we already know about the organization. Generally, I think LeDoux's downward causation descriptor is partially useful - although my definition of it is more elaborated. I am impressed by the refined emotional inputs that seem to be available to mammals vs. most other classes of vertebrates and all other living things.

Since all living things must be able to respond to their environment with behavior - then it seems that some final go, no-go decision ability must be present as an enabling element for that behavior. For any behavior to occur, a behavior candidate must be produced and a behavior decision, or perhaps a chemical equivalent of what we call a CNS mediated decision, must have been made within that animal - to execute that behavior.

Important stuff,
As species evolve and ecological niches are occupied, it seems that there has always been a built-in need for a sort of evolutionary one-upsmanship. It seems reasonable that evolution would find the easier solutions first and would generate the more complex solutions to problems of survival most recently. The first life forms just responded in set ways to specific environmental inputs.

At some time an organism evolved the ability to select the most appropriate from two possible behaviors in its repertoir. I see this as a singular evolutionary event - a meta-strategy that greatly enhanced the survival of its organsim's DNA. That has led to all advanced life forms including us, where that ability has reached its apotheosis.

Basically, I see humans as an animal with extremely advanced abilities to choose from a very wide range of behaviors - by using a large set of weighted, qualitatively-different inputs and allowing a kind of outcome optimizing negotiation among them. Just how this works is what this discussion (and evolutionary psychology) is about IMO.
I think generally that more refined inputs in more advanced animals are processed at the highest levels (in the most recently evolved brain regions) and reduced to successively simpler emotional forces as they work their way down to that place (wherever it may be) where that go or no-go decision is made. This is a type of downward causation I can appreciate.

Note that I see emotions not just as synapse activity but as changes in body state. In the CNS these brain state changes are due to chemical neurotransmitters that are produced along with and in response to synaptic activity. The activation of a particular mental image can produce a flood of serotonin in one brain area, for a simplified example. There are dozens of chemicals that can act as neurotransmitters and much remains to be learned about how they all work. But, I suspect these chemicals are responsible for what animals with a CNS experience as the emotional forces that a) produce a candidate behavior from our repertoir, b) sometimes consider it in context and then c) execute it - or not.

Our decision-mechanism is designed to support our survival and ultimately our ability to reproduce. We are designed to respond emotionally to threats and opportunities we come across in our environment. We can't avoid that. The greater the threat or opportunity, the stronger the emotion produced.

Many of our behavior decisions are made without intellectual assistance (cognition). It's easy to see how the emotions produced by various subconscious inputs could be used to produce behavior decisions. Thousands of psychological tests have been done that have verified and mapped the existence of this subconscious mechanism.

In humans, I believe intellect provides the most refined inputs, furthest from that final arbiter device. I think we subconsciously and emotionally choose to engage our intellect for certain classes of decisions. We need to recognize the decision as one where our intellect can provide useful input - and we must be free from very strong emotions (like great fear or sex) that can inhibit our intellect - and we must also have some time available for a decision because our intellectual computer is restrained to sequential operation. Logical steps must follow one another so we must reason through a problem step by step generating partial solutions that feed into the next step and so on.

Our basic decision mechanism though is not sequential. It is designed to accept emotional inputs from a variety of excited brain regions and produce an effectively instantaneous output.

For the basic mechanism I imagine a threshold detector with several op-amps connected to the non-reference input representing the various input channels. Each signal is generated by a common mental image representing a candidate solution to a problem - instinct, disposition, beliefs, social instincts, etc. acting on different brain regions designed to generate those signals. But this basic circuit is representative of the function that I imagine occurs in there.

I think we inhibit that instant decision output for those behavior decisions where we engage our intellect - although we may still feel its pull. Then, after we have produced that slower intellectual conclusion we automatically reduce it back to an emotional value, weighted appropriately for the context and our emotional confidence in the calculation. Once we produce that weighted emotion, which is the effective value of that intellectual calculation to our survival as best as our CNS can determine - the final behavior decision is produced as a summation of all inputs, now applied.

I'm sure that's over-simplified but I suspect this is the same kind of thing that is happening in our minds when you describe,
So in effect, we seem, according to social cognitive theory, to start out with a conclusion, whereas we feel as if we are starting out from a blank or neutral position. The place where we might then use "intellect" in the way we like to think of that capacity, is to reassess our initial summary impression.
I hope you don't mind that I am responding to your posts by painting more detailed pictures of what I am seeing. Your word pictures are valuable and have changed my view. I no longer see the final decision occuring in the limbic system, for example. I was just uncertain before. Now I'm pretty much dissuaded. I'm just pointing out areas of our respective views that seem significant or even just interesting. If I find something that seems significantly incongruent I'll focus on that - but so far things seem to fit OK.

For example, you said,
My only disagreement with your idea is where I think it seems to imply that mammalian brain structures somehow took over the job from everything that came before, and I don't see that being likely.
I didn't mean to imply that. I saw (and see) the limbic system wrapping around older structure and adding some new specialized inputs to the same basic behavior choice mechanism.

Similarly, taking it a step further, I don't see the expanded frontal cortex taking over decision making in primates, just adding new tricks suited to a further distinguished lifestyle.
This is exactly what I did mean to imply in my description. Most psychological brain models seem to start from the premise that our frontal cortex or some other human cognitive structure is where our special human decisions are made. That's LeDoux's downward causation that I strongly disagree with.

There are some other things in your post that I need to think about further but I thought I'd comment on where I am now.

(Anyone who wants to reply to this should read my addendum to this first, in the following post.)

Thanks much, Margaret

Last edited by Margaret McGhee; June 1st, 2006 at 06:15 PM.
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