consciousness

I've just finished Mary Roach's entertaining book, Spook: Science Tackles the Afterlife.

I haven't read Roach's previous book, Stiff, which explores some of the odd things that happen to cadavers after people die. Being an anthropologist, I guess I know about as much about that topic as any reasonable person could want.

But I recently saw a really interesting documentary about Harry Houdini, focusing on his other career: debunking mediums. Flipping through Spook in the bookstore, it looked like a good chance to follow up on the subject. The book didn't disappoint, and broadened beyond the spiritualism movement to describe other loopy ideas about the afterlife.

We've been watching this show on the SciFi channel, Mind Control, in which British "psychological illusionist" Derren Brown. Brown is sort of like a much less skeevy Criss Angel. Not that much less skeevy -- Brown is best-known for playing Russian roulette on TV. And like every aspiring mentalist, he's mastered that eyes-focused-somewhere-inside-your-skin look.

To tell you the truth, the show comes on after Flash Gordon, and, well, I'm a committed Flash Gordon nut.

Anyway, the beauty of the show is that Brown lets you in on the trick, at least some of the time, since the "trick" is really just the power of suggestion. With a highly rehearsed script including repeated cues, he can make people forget what they were thinking before, and to think what he wants instead.

I'm totally going to try this on my classes! Look out, students. Especially on evaluation day....

So in today's science section, the NY Times has a story by George Johnson, who got to sit in on Magic Day at the Consciousness meetings. It sounds pretty cool:

After two days of presentations by scientists and philosophers speculating on how the mind construes, and misconstrues, reality, we were hearing from the pros: James (The Amazing) Randi, Johnny Thompson (The Great Tomsoni), Mac King and Teller -- magicians who had intuitively mastered some of the lessons being learned in the laboratory about the limits of cognition and attention.

"This wasn't just a group of world-class performers," said Susana Martinez-Conde, a scientist at the Barrow Neurological Institute in Phoenix who studies optical illusions and what they say about the brain. "They were hand-picked because of their specific interest in the cognitive principles underlying the magic."

Page 2 of the story gums its way into the confusing topic of qualia. Now, Qualia Day in my biology of mind course would be a good one to try out the mind control -- that is, on the students who really can't be convinced that philosophy is fun.

This is a problem that's big and little at the same time -- from a certain perspective, nothing seems more central than qualia, and yet that centrality seems to have no observable effect on anything else. It's hard to avoid though -- because if you're going to discuss the mind from an evolutionary perspective, you have to lay out what kinds of things evolutionary biology is well-placed to explain. "Qualia" are among the few things that aren't (necessarily) on that list.

So stick to the front page if you're not interested -- and the last half of page 3, where the Amazing Randi gets a few words:

"Allow people to make assumptions and they will come away absolutely convinced that assumption was correct and that it represents fact," Mr. Randi said. "It's not necessarily so."

That's one of the reasons we used to love Jonathan Creek -- at least, until they got rid of Maddie. If your perception can be snookered by assumptions, then your logic can easily go with it.

The beauty of magic is that you know it's not possible, and yet your senses believe it anyway.

[Teller] left us with his definition of magic: "The theatrical linking of a cause with an effect that has no basis in physical reality, but that -- in our hearts -- ought to."

What's more amazing? That these scientists got a show from some of the best non-skeevy magicians in Vegas? Or that Teller talks?

I like this post on octopus intelligence by Chris Chatham. He reviews an article by Jennifer Mather that claims that cephalopods have primary consciousness. Here is the article's abstract:

Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and tactile cues, and may have domain generality and form simple concepts. Third, these animals are aware of their position, both within themselves and in larger space, including having a working memory of foraging areas in the recent past. Thus if using a 'global workspace' which evaluates memory input and focuses attention is the criterion, cephalopods appear to have primary consciousness.

Chatham's post summarizes the main points made in the article, it's a good place to start. For example, this point about sociality and communication in squid is illuminating:

Octopus performance on traditional behavioral tests of theory of mind is difficult to evaluate, since octopi are primarily solitary animals. The classic "mirror test" of consciousness is also inconclusive since octopi seem relatively unreliant on vision. Squid, on the other hand, are more social animals and are apparently more reliant on vision (considering they have relatively sophisticated real-time control of the pigmentation of their skin. Some have proposed that these two feature might permit for the emergence of language among squid. Sure enough, patterns of skin pigmentation have been to have a lexical but not grammatical communicative structure (i.e., skin color seems to convey detailed information about current sexual or emotional states, without seeming to have a rule-like structure for how those signals can be combined).

The main reason for an anthropologist to be interested in cephalopod cognition is that their brains evolved largely independently from ours. The common ancestor of vertebrates and cephalopods had nothing like the neural complexity and brain anatomy of either mammals or cephalopods, so most shared functional capacities in these animals must be convergent. As the review notes, there are both functional and anatomical convergences, and the question is to what extent the form and function are related. Many of the genes that determine neural development in these lineages are shared from their common ancestor, so there is also an interesting question about the extent that genetic homology may predispose descendant lineages to functional and anatomical convergences.

I think I'll include this article on my reading list next time I offer Biology of Mind (which should be fall 2008, for students who may be wondering).

References:

Mather JA. 2007. Cephalopod consciousness: behavioural evidence. Consciousness and Cognition (in press) doi:10.1016/j.concog.2006.11.006

I was going to make it a quote of the day, but this column by NYT writer Dennis Overbye is worth reading in full. It's about the march of science against free will:

"If people freak at evolution, etc.," [philosopher of science Michael Silberstein] wrote in an e-mail message, "how much more will they freak if scientists and philosophers tell them they are nothing more than sophisticated meat machines, and is that conclusion now clearly warranted or is it premature?"

As Overbye points out, it's far from a new problem:

That is hardly a new thought. The German philosopher Arthur Schopenhauer said, as Einstein paraphrased it, that "a human can very well do what he wants, but cannot will what he wants."

Einstein, among others, found that a comforting idea. "This knowledge of the non-freedom of the will protects me from losing my good humor and taking much too seriously myself and my fellow humans as acting and judging individuals," he said.

Well, a hopeful fatalism is one of the attractions of a belief in predestination. But personally, I think when quantum physicists start talking about free will, it is just anthropology-envy. Hey, if you want to study human action, then make a proper study of it! You don't need Gödel, for goodness' sake! That's just a way to say, "Harrumph, the ancient experts show us by long proof that the problem of free will lies deep in a paradoxical enigma. Murmpheaoww! Give me another cigar!"

It's like your doctor quoting Galen when he prescribes an antibiotic. Totally irrelevant!

I don't really think that the central metaphysical question here -- is human action something other than deterministic or random? -- is one that most of us worry too much about. Most people who are thinking about "free will" have in mind things like whether SS stormtroopers were responsible for various reprehensible actions, or whether "just following orders" is a valid excuse.

To my mind, if you've gone all the way to the subatomic level to talk about free will, then you've already answered the really important questions. That is, unless you want to posit an "obey-evil-dictator" neutrino!

Anyway, the article presents a good basic-level overview of Libet's experiments and various follow-ons. The problem is when it derails into whether Cretans are liars and other detours. Seth Lloyd is extensively quoted about whether computer laptops have free will of a sort. Well, they probably do, and in the human sense, besides! Who hasn't thought that her own computer is deliberately thwarting it's master's subtle plans? That's probably more evidence than we require to assume that other people have free will!

I can understand why one might object to a human-computer analogy, but a human brain that is a product of evolution must be computer-like in some important ways. The other side of that analogy is that computers are like brains in some important ways.

"Free will" doesn't mean "unpredictable action", after all. If it did, there would be no sense in predicting anything for the coming year. Which is what I'm setting my mind to this morning!

Why else would I start the year with an overly-glib post about an ancient philosophical problem?

Philosopher of mind John Searle has written a review of Nick Humphrey's new book, "Seeing Red: A Study in Consciousness."

He doesn't much care for the book's hypothesis about the nature of consciousness, which involves the idea that sensation (roughly, qualia by another name) is separate and parallel to perception.

In a word toward explaining the quote below, the review uses a recurrent metaphor throughout. Searle proposes that Humphrey has attempted to set mind and brain equal to each other, in the form of an equation. But like any equality in physical science, this exercise requires that the measurement units be made the same on both sides of the equation. In Searle's view, this is where the book is misguided -- Searle claims that we should be looking for not an equality of mind and brain, but instead a causal account of how the physical brain gives rise to mind.

The problem with the equation mode of thinking:

The enterprise was bound to fail because the equation does not solve the problem; it presupposes that the problem has already been solved. The problem is to explain the relation of consciousness to brain processes, specifically to explain how brain processes cause (give rise to, produce, bring about) qualitative subjectivity. We already have qualitative subjectivity on the left-hand, mind, side of the equation, by definition. The question then is: How does it get into the right-hand or brain side? But that is precisely the mind-body problem, the problem that the equation was supposed to solve. Humphrey does not address that question directly; rather, he changes the subject. Our question is: How do objective third-person brain processes right here and now (as well as in earlier evolutionary times) cause our conscious states? What specific parts of brain anatomy do it and how do they work? His question is: Assuming that perception is unconscious, how might conscious sensations have evolved and what functions would they perform? His answer, in brief summary, is that they evolved by monitoring our responses to input stimuli and they function to give us a sense of "the Self." I think he is wrong to separate perception from consciousness; all the same, some evolutionary story about consciousness must be right. But whatever evolutionary story may be proposed is an answer to a different question from the causal question. The only part of his account that even hints at an answer to the causal question is the discussion of feedback mechanisms. But he does not tell us how we get from the feedback mechanisms to qualitative subjectivity.

I italicized the first sentence here because it strikes me as very useful -- one could for example make the same observation about Daniel Dennett's "Cartesian theater" account of consciousness. The problem is that if your theory asserts that the "problem" of mind is not really a problem, because mind just is some aspect of brain physiology, then you really are just presupposing that the problem has already been solved, rather than actually proposing some solution.

Searle is, as he often has been, a persuasive proponent of the idea that consciousness remains to be explained.

This could be a very long post, but isn't -- surely a few other short ones and a longer one will follow this summer. If you've been following, you will remember that I'm beginning to ramp up for my fall course on biology of mind.

Consciousness, of course, is one of the most difficult issues, because there is so much disagreement about what it actually is and how it relates to other mental functions. In that vein, this paper by Seth and colleagues is useful, because it compares and contrasts 17 different criteria for consciousness and their consequences as applied to humans and other mammals. They range from baseline (EEG readings) to long-term observational ("consciousness facilitates learning"). Here is the abstract:

The standard behavioral index for human consciousness is the ability to report events with accuracy. While this method is routinely used for scientific and medical applications in humans, it is not easy to generalize to other species. Brain evidence may lend itself more easily to comparative testing. Human consciousness involves widespread, relatively fast low-amplitude interactions in the thalamocortical core of the brain, driven by current tasks and conditions. These features have also been found in other mammals, which suggests that consciousness is a major biological adaptation in mammals. We suggest more than a dozen additional properties of human consciousness that may be used to test comparative predictions. Such homologies are necessarily more remote in non-mammals, which do not share the thalamocortical complex. However, as we learn more we may be able to make "deeper" predictions that apply to some birds, reptiles, large-brained invertebrates, and perhaps other species (Seth et al. 2005:119).

There are few conclusions, mainly just a description of properties that ought to receive more attention in relationship to each other and to consciousness.

References:

Seth AK, Baars BJ, Edelman DB. 2005. Criteria for consciousness in humans and other mammals. Consciousness and Cognition 14:119-139. DOI link

Cited in a lecture I heard today, from T. H. Huxley:

How it is that anything so remarkable as a state of consciousness comes about as a result of irritating nervous tissue, is just as unaccountable as the appearance of Dun when Aladdin rubbed his lamp.