Thursday, April 17, 2008

Consciousness, free will, etc.

For quite a long time, the subject of "consciousness" was not considered especially suitable for scientific investigation. A tremendous amount has been written about it, of course. But most of that has been written by philosophers rather than working scientists. Quite a few, if not a substantial majority, of philosophers seem to think that consciousness is a "mystery" that isn't likely to be understood scientifically anytime soon, if ever.

Well, on one hand, when a subject is not very amenable to scientific investigation, then it usually is philosophers, rather than scientists, who write and speak about it. Only when you see that situation change, and you have actual experimental scientists working on the problem and having the technology to actually conduct meaningful experiments, is it time to regard the subject as fair game for science.

At one time even physics was a subject discussed more by philosophers than by scientists. But that changed when people like Galileo and Newton came along, followed by many others. In regard to consciousness, perhaps the technology known as "functional MRI" may be the factor that tips the scales towards real science.

On the other hand, my general opinion of philosophers is well expressed by a quote attributed to one of the all time greatest scientists, C. F. Gauss: "When a philosopher says something that is true, then it is trivial. When he says something that is not trivial, then it is false."

However that may be, we are now in fact seeing real scientific work being done on the subject of consciousness. It's a vast field, I can only scratch the surface here, and I won't go into much detail about any of this. But perhaps a good example of relevant recent research on consciousness is this:

Brain scanner predicts your future moves
Long before you decided to read this story, your brain may have already said "click that link".

By scanning the brains of test subjects as they pressed one button or another – though not a computer mouse – researchers pinpointed a signal that divulged the decision about seven seconds before people ever realised their choice. The discovery has implications for mind-reading, and the nature of free will.

More reports on this research: here, here
Much more: here

Seven seconds. Think about that for a bit. Where, exactly, is "free will", if the brain has already made, or almost made, a decision seven seconds before one is even conscious of a decision having been made?

Sure, one can argue that "free will" comes into play near the final stage of the process, when a course of action is consciously considered before commitment is made to it. Perhaps. But consider something like drug addiction. Just how much "free will" does an addict actually have to resist his/her cravings? Rather little, no? There's quite a bit of research into addiction now, and it is supporting the idea that addictive behavior is largely driven by brain chemistry. I could cite dozens of recent reports in this area, but I need to move on to other stuff right now. Maybe more on addiction later.

Oh yes, and there are a number of other brain states that appear to significantly affect behavior much more strongly than does conscious deliberation. States such as pain, extreme hunger or thirst, the experience of being tortured by agents of the U. S. government, etc.

There's another area of research that comes to mind in connection with significant unconscious influences on people's thoughts and behavior. Psychologists have a term for it: "priming". What it means is that one can manipulate, at least on a statistical basis, the behavior of another person, such as an experimental subject, a voter, or a "consumer", by subtly exposing the subject to various kinds of cues before eliciting the behavior to be manipulated. The subject may be consciously aware of the cues, but not of how they affect subsequent behavior.

Again, I could probably come up with many examples of studies on this if I had more time. Maybe later. Just two examples now, this story that appeared last year: Who’s Minding the Mind?. I wrote about that here, along with another, somewhat older story (A New Study Suggests A Relationship Between Fear Of Death And Political Preferences). Something to think about in this election year.

Moving right along, this all sets the stage for the following very recent report:

Blind to Change, Even as It Stares Us in the Face
The phenomenon that Dr. Wolfe’s Pop Art quiz exemplified is known as change blindness: the frequent inability of our visual system to detect alterations to something staring us straight in the face. The changes needn’t be as modest as a switching of paint chips. At the same meeting, held at the Italian Academy for Advanced Studies in America at Columbia University, the audience failed to notice entire stories disappearing from buildings, or the fact that one poor chicken in a field of dancing cartoon hens had suddenly exploded. In an interview, Dr. Wolfe also recalled a series of experiments in which pedestrians giving directions to a Cornell researcher posing as a lost tourist didn’t notice when, midway through the exchange, the sham tourist was replaced by another person altogether.

The article is a report by Natalie Angier on research into consciousness and attention by neuroscientist Jeremy Wolfe. I won't attempt to say much about it, except that it concerns the interplay of consciousness and attention. And how in some sense we are not really conscious of as much as we think we are. The sense data are streaming into our brains, and they do register at some level that appears to be conscious. But in fact, only a part of the information stream that is the focus of "attention" actually seems to matter." Attention" is the brain's mechanism for limiting actual processing to just a part of the data stream that, somehow, seems most important.

I won't attempt to summarize more than that. Angier is a pretty good writer. Read the article for yourself. Actually, speaking of Angier, I should remark that I have expressed reservations before about her writing style (here). There I described her style as "too flowery and gaudy for my taste". The article mentioned above is fairly tame in that regard. But sometimes what she writes seems, to me anyhow, to be best described as somewhat twee.

Now, "twee" is a word you may not be familiar with if you have been exposed mainly to U. S. English (and you don't do crossword puzzles). It's a British word. A rough American equivalent might be "affected". However, I used "twee" to make a point. Namely, that if you didn't know the meaning, but you looked it up, I'm pretty sure you won't have much trouble remembering it. Why? Because I brought it to your attention.

So you see, although you were probably conscious of the word when you read it, having had your attention focused on it will tend to be the catalyst that gets it added to your memory.

The brain has other mechanisms for directing consciousness in certain ways and for raising the probability that certain kinds of data get remembered. Emotion is one such psychological mechanism that has this effect. I've touched on this tangentially when I wrote about stress and memory here. Also think about "flashbulb memories".

The point is that sensory data that is accompanied by significant emotional valence tends to be preferentially stored in memory. Various hormones and growth factors (such as BDNF) seem to play a role in this process. Consciousness per se... not so much. You have been conscious of quite a lot that you have already forgotten the next day (such as, perhaps, what you had for breakfast a day or two ago).

Here's another report of recent research that tends in the same direction. It concerns the role of emotion in the sense of smell, and which olfactory experiences tend to be stored in memory:

One Bad Experience Linked To Sniffing Out The Danger
Each human nose encounters hundreds of thousands of scents in its daily travels perched front and center on our face. Some of these smells are nearly identical, so how do we learn to tell the critical ones apart?

Something bad has to happen. Then the nose becomes a very quick learner.

New research from Northwestern University's Feinberg School of Medicine shows a single negative experience linked to an odor rapidly teaches us to identify that odor and discriminate it from similar ones.

More reports on this research: here, here.

I don't think I need to comment further on that, with respect to how the emotional circuitry of the brain influences the memory storage circuitry.

Time to wrap up now. I'm going to indulge in a bit of anecdotal reporting on a few of my own observations on consciousness. This is just speculation on my part, not scientific data at all, of course. Think about your own experiences and see whether they aren't consistent with the possibility that consciousness is just another brain mechanism, which serves various purposes, and interacts in different ways with other brain mechanisms. If this is so, eventually we should be able to understand scientifically what the biology of consciousness is.

First off, I'll note that I recently had a colonoscopy. (Nothing bad found. Thanks for asking.) The most interesting part of the experience was how readily consciousness can be turned on and off. Before the procedure began, I was injected with two drugs: Demerol and Versed. The former blocks pain. The latter is a strong sedative that basically turns off consciousness for a brief, fairly predictable period of time.

For a couple of minutes after receiving the Versed, I didn't notice anything unusual, no drowsiness, no disorientation, nada. I just looked around and noticed various features of the immediate environment, such as the staff and the monitoring instruments. I can still picture that stuff fairly clearly. Of the next half hour or so while the procedure was going on, I can recall nothing at all. And then I was awake again, and everything seemed pretty normal. I can recall that period clearly too.

What I conclude from this is that consciousness and memory formation are both processes and/or mechanisms that can be turned off pretty mechanically with a simple chemical. Probably the memory formation is turned off first, so that the intermediate state of drowsiness (if it even occurred) was not remembered. And then as soon as the chemical has been metabolized away, consciousness and memory formation resume with little aftereffect. (Physicians maintain that a patient's judgment can be compromised for several hours afterwards. Perhaps so, but I could detect little evidence of that.) I was also told that patients under the effects of the drugs are still consciousness enough to follow verbal instructions. But of course, I have no memory of whether this is true.

This experience was not like falling asleep normally, when there is usually a definite period of drowsiness that one can often remember the next day. Nevertheless, once asleep one is no longer conscious in the usual sense. Again this suggests that consciousness is just a mechanism that can be turned off (though not by means of volition, unfortunately) at appropriate times.

But we all realize that many mental processes do not cease when we are asleep. For instance, perceptual data is still coming in and processed by the brain to some extent. Noises, especially, that can and do wake us up. Then there is dreaming, which seems to engage large parts of the machinery of consciousness, including emotional subsubsystems (fear and pleasure), and perceptual processing systems of vision and hearing – only on internally generated rather than external sensory data. Sometimes external perceptual data becomes part of the dream consciousness, but usually not.

Another interesting aspect of dreaming is how it interacts with memory. We all know how quickly, after we wake up, we forget about what we may have been dreaming. This suggests that the short term memory system has been functioning, but loses its content more or less as usual. Intermediate and long term memory systems seem to be shut down. It's very unusual (in my experience) to remember any dreams several hours later, unless I happened to think of them immediately after waking up.

Only, this doesn't seem to be entirely true. I've not infrequently had the experience with dreams, when I can "remember" details of being in places and situations and in the company of people that I've encountered in other dreams, perhaps not at all recently. So it seems that there is some sort of long term memory mechanism and storage capability that is specifically dedicated for use while dreaming. Perhaps this is just an aspect of the déjà vu effect.

Another intesting question about the state of consciousness during sleep is whether, or to what extent, the brain continues to engage in creative problem solving. We all know about the advice, when one has a difficult problem, to "sleep on it". This does seem to help a little, but probably it's more a case of letting sleep restore the freshness and alertness of one's mind. Ceasing to think about problems for awhile (whether hours or days) often has similar benefits. I'd say that I experience creative insights into problems rather more often in some place like the shower or out on a walk than I do right after awakening. So it doesn't seem to me that a great deal of actual ratiocination is going on during sleep. At least in my experience.

One last sort of observation, concerning how attention facilitates memory. I think most people find it a little difficult to recall what they've had to eat for lunch even a day or two ago, certainly a month or even a week ago. Unless, that is, there was something unusual about the circumstances of the meal. Such as eating something one hasn't tried before, or at least not for a long time. Or having a meal in a restaurant or location one hasn't eaten in often (or ever). In such cases, one tends to recall many little details of the experience, not just the items in the meal itself. For instance, one tends to remember noticing specific ingredients in what's eaten, and what flavors seemed to be especially pleasant or unpleasant.

When I think about it, I can still recall where I was the first time I had a cola beverage, and how I enjoyed it. I was only six or so. Now, perhaps what I can remember was not actually the first time. And perhaps I'm only remembering past experiences of having that memory. But still... this is about an experience that was decades ago, and without particularly intense related emotions, just general pleasure. But the experience was marked by having my full attention at the time. Needless to say, I can't summon up the perceptual experience of (probably) any other consumption of a similar beverage... except the one I had today.

From that experience, I draw the conclusion that attention is a mechanism which is separate from consciousness, yet which regulates it in such a way that essentially permanent long term memories can be formed. I don't think it's too much of a stretch to imagine that specific biological features will eventually be identified that implement the mechanisms of attention and consciousness in general.

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6 Comments:

Anonymous Anthony D'Amato said...

Did you know that one does not remember colors, but rather one calls up the visual mechanism that allows one to picture colors? When the retina's optic nerve is damaged so that a person can no longer see a certain color, say red, thereafter the person cannot remember what red looked like.

11/15/2008 12:24:00 PM  
Blogger Charles Daney said...

Did you know that one does not remember colors, but rather one calls up the visual mechanism that allows one to picture colors?

No, I didn't know that. In fact, I'm not sure what it means to "remember" a color, except by calling upon the brain's visual equipment. And I don't immediately see what the optic nerve or even the retina has to do with it. Do you have references for more detail about this?

11/16/2008 05:56:00 PM  
Anonymous Dudley Brooks said...

Putting in a good word for philosophers:

Philosophers, at least those of the analytical school, play an important role by pointing out such things as the unstated assumptions of a scientific experiment or viewpoint, whether a particular result really does answer the questions it proposes to answer, what questions still remain, etc. This is the role of philosopher-as-critic.

This is especially true with respect to the mind. Even if you believe, as I do, that we will find a physicalist explanation for everything, even qualia, the philosopher will still correctly point out that this depends on what we mean by "explain".

Besides, some scientists are also philosophers, and vice-versa.

10/26/2009 12:34:00 PM  
Blogger Charles Daney said...

Dudley,

I do tend to be pretty harsh on philosophers, but it's true that they do have their place.

It's appropriate for philosophers to apply all the tools of reason to questions about ethics, aesthetics, epistemology, and what (if anything) is the "meaning" of life. And so forth.

Those are all issues that can't be studied by science as we know it, and they may always elude science.

Then there are issues that science may one day be able to handle, especially questions of psychology, consciousness, free will, and so on. I don't think science is quite there yet, though there is much it can do.

However, once questions come within the ability of available technology to study in what we currently understand to be rigorous science, then it seems to me that philosophers are less helpful. Under these conditions, I think scientists are fully capable of doing what you say that philosophers do. It is part of the *job* of scientists to ask the questions about their science that you list.

As an example, before we had the kinds of astronomical instruments we have only recently developed, it was reasonable for philosophers to speculate about how the universe might be organized. That's no longer true. Such things are empirical questions now.

There are still plenty of questions science can't reach yet. The meaning of quantum mechanics, for instance. And what may have happened "before" the big bang. But even in those areas, a philosopher would have to understand a lot of pretty deep science in order to offer a useful opinion.

I think most philosophers understand their role vis a vis scientists these days; it doesn't strike me as a terribly controversial matter.

But those philosophers who are, for instance, into New Age woo... well, I don't think they have much that's very useful to contribute.

10/28/2009 03:04:00 AM  
Anonymous Dudley Brooks said...

I basically agree -- certainly about the "fringe" philosophers. I would have my cake and eat it too by saying that when scientists ask "deep questions" about their subject matter, they become philosophers.

Also, in Philosophy of the Mind, Philosophy of Science, and Philosophy of Mathematics, there are several philosophers who are quite grounded in the science. In math, many of the major philosophers are actually working mathematicians.

And the scientists don't always ask the questions, or don't ask them correctly. I recently read an article by the philosopher Huw Price pointing out that many physicists' or cosmologists' discussion of the arrow of time is circular: They correctly define it as "the direction in which entropy increases" but then "explain" why entropy only increases in one direction by saying that statistically a disordered state is more likely to follow an ordered state, not noticing that "follow" already presupposes the direction they are trying to explain. [Hawking correctly avoids the circularity, whether his idea turns out to be correct or not, by supposing a cosmology which has no presupposed preferred direction but in which the two ends are different, and the difference causes entropy to proceed in only one direction.]

And what about Popper, Kuhn, Lakatos, Feyerabend? Granted, their ideas may not play much of a role in day-to-day science, except possibly for Popper's notion of falsifiability. And granted, they don't even agree with each other. But surely they do a worthwhile critique of science, that the busy specialist may not have time to think very much about.

I disagree that ethics, aesthetics, epistemology, and the meaning of life can't be discussed scientifically. I think the first three can quite meaningfully be explained by evolutionary biology (and its offspring, psychology) and the fourth by, well, all the sciences. I think that everything is the proper subject of science ... and of philosophy.

10/28/2009 11:02:00 AM  
Blogger Charles Daney said...

Very stimulating discussion, Dudley!

In math, many of the major philosophers are actually working mathematicians.

I did graduate work in math, and I wasn't aware of any philosophers who contributed much outside the field of logic and foundations (including set theory). In the latter, clearly, there's Godel, who was certainly both mathematician and philosopher. And farther back, Russell and Whitehead. Godel, of course, negated much of the work of R & W.

Since I can't keep on top of much of what's going on now in math, I'm wondering who you have in mind as major philosophers who are (currently) working mathematicians.

It does seem to me that the most important work in 20th century math (apart from L/F) has very little contribution from philosophers. I'm thinking of stuff like algebraic geometry, algebraic topology, differential geometry, functional analysis, differential equations, etc.

I know there are also mathematicians-philosophers of the "intuitionist" and "constructivist" traditions who eschew non-finitistic methods, so that they'd consider much of modern analysis to be merely BS, at least if I understand their general idea. To which, my response is "Huh?"

And the scientists don't always ask the questions, or don't ask them correctly. I recently read an article by the philosopher Huw Price pointing out that many physicists' or cosmologists' discussion of the arrow of time is circular

Don't such controversies exist because they concern matters that are currently not subject to empirical test? My supposition is that once empirical testing becomes possible, the controversies get resolved one way or another. However, I'm not up on this area, so I don't really know.

And what about Popper, Kuhn, Lakatos, Feyerabend?

The question I'd ask is: What scientific results would we not have if they hadn't written what they did? In other words, what results did they contribute to?

I wouldn't deny, though, that some of their ideas - especially Popper's - may have helped avoid unproductive work. And that's surely useful. I suppose one could say that there are scientists who did great things they might not have done if they hadn't learned from such philosophers. However, it's pretty hard to identify such cases. There might also have been brilliant people who didn't go into science because these philosophers somehow persuaded them against it. (Especially someone like Feyerabend.)

I disagree that ethics, aesthetics, epistemology, and the meaning of life can't be discussed scientifically.

Absolutely I agree that science can study some of the same matters that these branches of philosophy also study.

For example, in aesthetics, there's this.

And in ethics, I'm very interested in questions such as how the sense of morality come about, from an evolutionary psychology point of view. You've probably found some of my blog articles, like this.

But it does seem to me that with ethics, for example, science and philosophy ask different kinds of questions. Science asks "how does the brain make moral judgments?" or "how did evolution lead to moral opinions about sexuality?" Philosophy, on the other hand, asks questions about whether actual or hypothetical moral/ethical opinions are "good" or "correct", irrespective of what evolutionary and neurobiological conditions led to them. I don't quite see how science can handle the latter sort of question, because it becomes an issue of saying what "good" means.

10/29/2009 02:39:00 AM  

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