Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Monday, August 9, 2010

Consciousness as a process that is entailed by molecular interactions

I'm now convinced more than ever that we are able to think unconsciously, for I actually came up with the following idea in my dream. I woke up in my dream (or half-woke up in my half-dream), saying to myself that I needed to write this down: Consciousness is a process just like a storm is a process; physical constituents of consciousness are molecules that constitute neurons and other elements in the brain, just like physical constituents of a storm are molecules that constitute air and other things that fly in the storm; consciousness is what appears to us when the molecules move in a particular way, just like a storm is what appears to us when the molecules move in a certain way.

Let me elaborate more. This idea arose from a question I had when I encountered the next passage about 15 hours before I had that (half-) dream. The passage was in Second nature by Gerald Edelman.


It is commonplace to talk of mental events or phenomenal experience as if they were causal. But in asmuch as consciousness is a process entailed by integration of neural activity in the reentrant dynamic core, it cannot itself be causal. At the macroscopic level the physical world is causally closed: only transactions at the level of matter or energy can be causal. So it is the activity of the thalmocortical core that is causal, not the phenomenal experience it entails. (pp. 91-92)



This passage is Edelman's answer to the classical question: "Are consciousness and 'mental events' causal?", but, to me, this was one of the only few parts that I felt not exactly convinced of in this otherwise brilliantly lucid book. I just wondered what a process is exactly. Edelman argues that consciousness is not causal because it is only a process. Although I was obviously able to understand the literal meaning of this argument, the argument didn't exactly feel right to me. What does Edelman mean when he says that consciousness is only a process? I needed some analogy or something to feel convinced.

That's how I woke up some 15 hours later in my (half-)dream. In it I said to myself the above statement (" Consciousness is a process just like a storm is a process") and that I need to write this down in order not forget this (I actually woke up and wrote it on my computer at 4:30).

In ordinary language, we often say a sentence like "the storm destroyed the house completely" as if the storm had the causal power. It makes perfect sense in conversation. Yet, the 'storm' is just a convenient expression in our ordinary talk, and in physical terms the 'storm' is nothing but the collection of multitude of molecules that constitute air and other things that fly in the storm.

The causal power lies in these physical elements (the physical world is causally closed). 'Storm' is a name we give to a particular type of process of the movements of these molecules. So in physical terms, it is molecules (or any other physical terms if you like), rather than the 'storm', that cause the destruction of the house (which is also constituted by the molecules. 'House' is another convenient word in our ordinary life). After all, "the storm destroyed the house completely" is all about causal interactions of molecules. In this sense, the storm is only a process that we give the name "storm", and not causal.

Likewise, consciousness is also a process, not an entity on its own. It is only entailed, Edelman argues, by neurons in interaction. When he talks about 'qualia' -- let's temporarily define 'qualia' as a particular state of consciousness that is 'felt' by the first person; I therefore equate qualia with consciousness here --, he says as follows:


Qualia are entailed by states of core neurons acting to yield complex integrative states that can shift to yield new states and conscious scenes. Qualia are thus no more caused by neural states than is the spectrum of hemoglobin caused by that protein's structure -- its so-called Soret spectrum is entailed by its molecular structure. (p. 145)


(Because of the lack of scientific knowledge, I have to assume that 'Soret spectrum' is (or similar to, or related to) 'Soret peak'.)

Given a particular molecular structure, a certain spectrum appears to us. However, the molecular structure does not exactly cause the appearance in the strict sense of physics because the structure doesn't appear that way in non-human beings with different mechanism of vision (or other perception). The appearance is rather a matter of the system that observes the structure. The appearance is, we should say, more entailed for us than generally caused by the structure in the sense of a physical law whose effect is not human-specific.

In sum, consciousness is entailed by certain interactions of molecules, not caused by them. Consciousness is not within the boundary of physics in the strict sense, but within human subjectivity. Consciousness is a process that humans become aware of given our biological structure. Assigning causal power to consciousness is like assigning a storm causal power; it makes sense in our ordinary language, but not in physics, as an ultimate form of science.








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Wednesday, June 2, 2010

'Final Theory' and Isaac Newton

Quotation from
'What Price Glory?'
The New York Review of Books, JUNE 10, 2010

I find it ironic that Weinberg, after declaring so vehemently his hostility to religious beliefs, emerges in his writing about science as a man of faith. He believes passionately in the possibility of a Final Theory. He wrote a book with the title Dreams of a Final Theory, and the notion of a Final Theory permeates his thinking in this book too. A Final Theory means a set of mathematical rules that describe with complete generality and complete precision the way the physical universe behaves. Complete generality means that the rules are obeyed everywhere and at all times. Complete precision means that any discrepancies between the rules and the results of experimental measurements will be due to the limited accuracy of the measurements. (p. 12)

(...)

Isaac Newton, the scientist who took the biggest single step toward the understanding of nature, saw clearly how far he was from any Final Theory. “I do not know what I may appear to the World,” he wrote toward the end of his long life,

but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.


Newton wrote more modestly than Weinberg of the ability of the human mind to penetrate the mysteries of Nature. Newton was a devout Christian, as dedicated to theology as he was to science. Newton was no fool.(p. 12)


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Saturday, March 20, 2010

Stop arguing about words

Quotation from

Silent Quantum Genius
by Freeman Dyson
The New York Review of Books, February 25, 2010, p. 23.


About Paul Dirac, who lead the second revolution in physics in the 20 th century, quantum mechanics.

He [=Paul Dirac] said, as Galileo said three hundred years earlier,that mathematics is the language that nature speaks. When expressed in mathematical equations,the laws of quantum mechanics are clear and unambiguous. Confusion arises from misguided attempts to translate the laws from mathematics to human language.

Human language describes the world of everyday life,and lacks the concepts that could describe quantum processes accurately. Dirac said we should stop arguing about words,stay with mathematics, and allow the philosophical fog to blow away. I consider Dirac's disengagement from verbal disputes about the meaning of quantum mechanics to be an essential part of his legacy. But I am,as usual,in the minority.













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Friday, March 12, 2010

Economics = Poetry + Mathematics?

Quotation from

THE DEFLATIONSIT: How Paul Krugman found politics
by Larissa MacFarquhar
The New Yorker, March 1, 2010, pp. 38-49.


"Economic geography" is about regional specialties. It explains why a particular region gained a comparative advantage with a particular product and benefits from economies of scale-- by history and accident.


"I explained this basic idea" --of economic geography-- "to a non-economist friend," Krugman wrote, "who replied in some dismay, 'Isn't that pretty obvious?' And of course it is." Yet, because it had not been well modelled, the idea had been disregarded by economists for years. Krugman began to realize that in the previous few decades economic knowledge that had not been translated into models had effectively lost, because economists didn't know what to do with it. (p. 45)



Krugman is superb at deciding what to explain and what not to:


He [=Krugman] could take an intriguing notion that had come up in real-world discussions, pare away the details (knowing just what to take out and what was essential), and refine what was left into a clean, clever, "cute" (as he liked to put it), and simple model. "It's poetry," Kenneth Rogoff, an economist at Harvard says. (p. 45)



Economic models often explains some aspect of really really beautifully at the price of neglecting more important aspect.


"I think there's a pretty good case to be made that the stuff that I stressed in the models is a less important story than the things that I left out because I couldn't model them, like spillovers of information and social networks," he says. But failure to represent reality accurately is rarely a fatal flaw in an economics model -- what's valued is the model's usefulness as an analytic tool. (p. 45)



Sometimes we choose to be ignorant to look smart.








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Tuesday, March 2, 2010

science of socially shared stories

Quotation from

HEAD CASE: Can psychiatry be a science
by Louis Menand
The New Yorker, March 1, 2010, pp. 68-74.

In this article, Louis Menand, a professor of English at Harvard, reviews The Emperor's New Drugs: Exploding the Antidepressant Myth by Irving Kirsch, a professor of psychology at the University of Hull, United Kingdom, and professor emeritus at the University of Connecticut in the United States.


Kirsch, according to Menand, concludes from his meta-analyses of antidepressant drug trials that antidepressants are just fancy placebos. But, then, how come that each drug had statistically significant superiority over the placebo when it was approved in the drug trial?

Kirsh argues that despite the scheme of double-blind tests, the patients (who are paid) can assume whether they're taking the drug or not by detecting in them side effects such as nausea, restlessness, dry mouth, and so on, which the placebo does not cause. Menand summarizes Kirsch's argument:


This means that a patient who experiences minor side effects can conclude that he is taking the drug, and start to feel better, and a patient who doesn't experience side effects can conclude that she's taking the placebo, and feel worse. On Kirsch's calculation, the placebo effect ― you believe that you are taking a pill that will make you feel better; therefore, you feel better ― wipes out the statistical difference. (p. 70)



The placebo effect is an established fact in experiments.


He [=Kirsch] cites a 1957 study at the University of Oklahoma in which subjects were given a drug that induced nausea and vomiting, and then another drug, which they were told prevents nausea and vomiting. After the first anti-nausea drug, the subjects were switched to a different anti-nausea drug, then a third, and so on. By the sixth switch, a hundred percent of the subjects reported that they no longer felt nauseous ― even though every one of the anti-nausea drugs was a placebo. (pp. 70-71)



It seems to me that science of the placebo is more important than science of developing new drugs, if your drive is science, not profit.


Menand reports that the effects of different treatments are only mixed:


Later studies have shown that patients suffering from depression and anxiety do equally well when treated by psychoanalysts and by behavioral therapists; that there is no difference in effectiveness between C.B.T. [=cognitive-behavioral therapy], which focuses on the way patients reason, and interpersonal therapy, which focuses on their relations with other people; and that patients who are treated by psychotherapists do no better than patients who meet with sympathetic professors with no psychiatric training. Depressed patients in psychotherapy do no better or worse than depressed patients on medication. There is little evidence to support the assumption that supplementing antidepressant medication with talk therapy improve outcomes. What a load of evidence does seem to suggest is that care works for some of the people some of the time, and it doesn't much matter what sort of care it is. Patients believe that they are being cared for by someone who will make them feel better; therefore, they feel better. It makes no difference whether they're lying on a couch interpreting dreams or sitting in a Starbucks discussing the concept of "flow." (p. 71)


Is this then, science of care, rather than science of the placebo, that should be explored? Or is it science of social expectation?


A narrative becomes a story when it matches social expectation; when it is socially (and/or culturally) accepted and shared. What we may need may be science of socially shared stories.









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Monday, February 8, 2010

Damasio on Mind and Body

Quotation from

Damasio, A., & Damasio, H. (2006).
Minding the Body. Daedalus, 135(3), 15+.



The brain is connected to the body through chemical channels as well as neural channels:

The chemical bath in which all body cells live and of which the blood is an expression--the internal milieu--also ends up sending signals to the brain, not via nerves but via chemical molecules, which impinge directly on certain parts of the brain designed to receive their messages. The range of information conveyed to the brain in this manner is extremely wide. It includes, for example, the state of contraction or dilation of smooth muscles (the muscles that form the walls of the arteries, the gut, and the bronchi); the amount of oxygen and carbon dioxide concentrated locally in any region of the body; the temperature and the pH at various locations; the local presence of toxic chemical molecules; and so forth.




'Body loop': Mental states => brain states => body states => brain states => mental states

The idea here is that the body and brain are engaged in a continuous interaction that unfolds in time, within different regions of the body and within mental space as well. Mental states cause brain states, which cause body states; body states are then mapped in the brain and incorporated into the ongoing mental states. A small change on the brain side of the system can have major consequences for the body state (think of the release of a hormone); likewise, a small change on the body side (think of a knife cut, or a tooth infection, or the rupture of an ulcer) can have a major effect on the mind once the change is mapped as a nociceptive state and perceived as acute pain.





'As-if body loop': Unfolding emotion => body states constructed in advance before (or even instead of) the emotional change => brain/mental states:

But this is not the only network that links mind and body--there is another we call the 'as-if body loop.' Some fifteen years ago, Antonio proposed that in certain circumstances, as an emotion unfolds, the brain rapidly constructs maps of the body comparable to those that would result were the body actually changed by that emotion. The construction can occur well ahead of the emotional change, or even instead of the change. In other words, the brain can simulate a certain body state as if it were occurring; and because our perception of any body state is rooted in the body maps of the somatosensing regions, we perceive the body state as actually occurring even if it is not. (This functional arrangement can work for emotion because there is no need for fidelity of information concerning the body states that define an emotion provided the kind of emotion in question can be detected without ambiguity.)




Mirror neurons as 'as-if body' device originated in its body first, and then in the body of someone else:

Mirror neurons are, in effect, the ultimate 'as-if body' device. The mirror-neuron system achieves conceptually what we hypothesized as the 'as-if body loop' system: the simulation, in the brain's body maps, of a body state that is not actually taking place in the organism. The fact that the body state the mirror neurons are simulating is not the subject's does not minimize the power of this functional resemblance. On the contrary, it stands to reason that if a complex brain can simulate someone else's body state, it can simulate one of its own body states. Take, for example, a state that has already occurred in the organism: it should be easier to simulate since it has already been mapped by precisely the same somatosensing structures that are now responsible for simulating it. In fact, we suggest that the as-if system applied to others would not have developed had there not been an as-if system applied to the brain's own organism.


Emotions are 'felt' in our flesh (hence, 'feelings'!):

The as-if body loop, the body loop, and mirror neurons all point to a few remarkable features regarding the perception of the body during the experience of an emotion: The emotion ends up felt in our flesh. The process unfolds in time and is both sensory and motor. The sensing of body changes leads to motor activations that, in turn, can be sensed. All of these steps have the power to evoke related knowledge held in memory.





Related posts:
A summary of Damasio’s “Self Comes to Mind” 

'Feeling' of language as a sign of autopoiesis 

Damasio (2000) The Feeling of What Happens 

Another short summary of Damasio's argument on consciousness and self http://yosukeyanase.blogspot.jp/2012/06/another-short-summary-of-damasios.html