mind

I know many readers are fans of Terry Pratchett, as I am. He has a long, heartfelt article about his experiences with PCA, a type of early-onset Alzheimer's. An excerpt:

When in Paradise Lost Milton’s Satan stood in the pit of hell and raged at heaven, he was merely a trifle miffed compared to how I felt that day. I felt totally alone, with the world receding from me in every direction and you could have used my anger to weld steel.

Only my family and the fact I had fans in the medical profession, who gave me useful advice, got me through that moment. I feel very sorry for, and angry on behalf of, the people who don’t have the easy ride I had.

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Jonah Lehrer went in to WALL-E (an enormously entertaining movie) and came out thinking of Darwin's Expression of Emotion in Man and Animals:

The emotional brain is actually the most ancient part of our cortical machinery, a piece of hardware that's been refined by evolution over the last several hundred million years. That's why, as Darwin pointed out, animals that are utterly lacking in self-awareness - he called them "creatures of pure instinct" - tend to express their emotions in the same manner as humans. Even more radically, Darwin suggested that these expressions were evidence that the animals were also experiencing emotion, even though they were just obeying some ancient biological drives.

Lehrer's recent book is Proust Was a Neuroscientist.

Wired's Brandon Keim covers a new study by Susan Goldin-Meadow, which shows a conflict between linguistic and gestural communication strategies:

"This may reflect the real thought that comes before language," said study co-author Susan Goldin-Meadow, a University of Chicago psychologist. "It seems pretty natural."

Goldin-Meadow's team asked forty people -- ten speakers apiece of English, Mandarin Chinese and Spanish, each of which follows the SVO order, and ten speakers of Turkish, which follows an SOV order -- to describe a series of simple actions, such as a girl turning a knob, with gestures.

Regardless of their native language, the subjects almost universally preceded object with verb: girl knob turns.
"We expected that the language they spoke would influence the language of their gestures, but it didn't," said Goldin-Meadow.

They propose the "meaning" of the study is that the gestural strategy here reflects the actual structure of symbolic communication in the brain. In that view, the linguistic version is a language-specific translation of the brain's version.

Theory of Mind does not require episodic memory?

The ability to interpret others' mental states and intentions, called "Theory of Mind," has been a key area of interest for those studying the evolution of primate and human social behavior. Often, people have imagined that Theory of Mind emerges as a correlate of self-awareness -- the ability to reflect on one's own mental states. As the model goes, a focal individual interprets another's mental state by imagining herself "in the shoes of" the other individual.

Well, this week's Science has a short paper by R. Shayna Rosenbaum and colleagues that presents evidence that the "in their shoes" model is wrong. First a mini-review of why you would believe the usual idea in the first place:

The idea that ToM is closely related to, and that it may depend on, episodic memory and autonoetic consciousness seems perfectly natural: that in order to imagine and make sense of other people's thoughts, feelings, intentions, and actions, we must rely on our autobiographical recollections (1). The ability to consciously recollect past personal happenings has been shown to be necessary for imagining coherent and detailed personal happenings in the future (2, 3). Both episodic memory and ToM emerge close in time in ontogenetic development (4). The neural substrate on which the two abilities rely is in many ways strikingly similar (1).

But they examined two patients with brain injuries that eliminated personal episodic memory. In both cases, the patients showed an ability to interpret the mental states of other individuals, even though they could not imagine future events in their own perspective:

The current findings are at variance with the idea that the ability to simulate or reconstruct one's own past mental states is necessary to imagine the contents of other people's minds (1, 2). Both K. C. and M. L. suffer from severe difficulties in consciously (autonoetically) recollecting any events from any period of their lives. Yet they have no apparent difficulty in taking other persons' perspectives and inferring other people's thoughts, feelings, and intentions, as revealed by the ToM tests. The findings imply that K. C.'s and M. L.'s ToM ability may depend on semantic memory and general knowledge abilities that are largely preserved in both cases (5, 6).

This may go along with last week's paper by Hamlin, Wynn and Bloom, which showed that infants develop an ability to evaluate others' intentions much earlier than had been thought:

Here we show that 6- and 10-month-old infants take into account an individual's actions towards others in evaluating that individual as appealing or aversive: infants prefer an individual who helps another to one who hinders another, prefer a helping individual to a neutral individual, and prefer a neutral individual to a hindering individual. These findings constitute evidence that preverbal infants assess individuals on the basis of their behaviour towards others.

This isn't quite the same as Theory of Mind -- the infants are getting a general idea of whether a person is nice, not evaluating specific intentions. But the study of the individuals who lack episodic memory suggested that they were using more general cognitive resources to enable their interpretation of others' intentions. That would presumably include the kinds of heuristics that these babies were developing to judge people as "helpers" or "hinderers".

It may be that Theory of Mind is built from exactly the kind of simple observations that the babies can use, and that rather than build a detailed "simulacrum" of another person's intentions, we can interpret their likely intentions based on general knowledge of what people are likely to do based on similar external signs. That kind of skill might vary quantitatively among primate species, and provides a possible evolutionary pathway for this important social ability.

References:

Hamlin JK, Wynn K, Bloom P. 2007. Social evaluation by preverbal infants. Nature 450:557-559. doi:10.1038/nature06288

Rosenbaum RS, Stuss DT, Levine B, Tulving E. 2007. Theory of mind is independent of episodic memory. Science 318:1257. doi:10.1126/science.1148763

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Mind control

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?

Same as it ever was

A couple of months ago, Seed magazine ran a conversation between singer/songwriter David Byrne (of the Talking Heads) and cognitive music researcher Daniel Levitin. It's a really interesting mix of topics, and reading David Byrne's thoughts on ideas like mirror neurons and exaptation is pretty remarkable.

DB: So when you watch a performance, sports for example, you're not only watching somebody else do it. In a neurological kind of way, you're experiencing it.
DL:Yeah, exactly. And when you see a musician, especially if you're a musician yourself--
DB: --air guitar.
DL: Air guitar, right! And you can't turn it off -- it's without your conscious awareness. So mirror neurons seem to have played a very important role in the evolution of the species because we can learn by watching, rather than having to actually figure it out step-by-step.

I noticed that Levitin seemed to be doing more and more of the talking as the conversation went on, but he makes it a good introduction to some current thinking on the evolution of musical ability and cognition.

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The Sunday NY Times is carrying a very long article about Williams syndrome by David Dobbs. I think it's a nice article, beginning with some anecdotes relating the lives of people with Williams, and then proceeding into the science:

After being ignored for almost three decades, Williams has recently become one of the most energetically researched neurodevelopmental disability after autism, and it is producing more compelling insights. Autism, for starters, is a highly diverse “spectrum disorder” with ill-defined borders, no identified mechanism and no clearly delineated genetic basis. Williams, in contrast, arises from a known genetic cause and produces a predictable set of traits and behaviors. It is “an experiment of nature,” as the title of one paper puts it, perfect for studying not just how genes create intelligence and sociability but also how our powers of thought combine with our desire to bond to create complex social behavior — a huge arena of interaction that largely determines our fates.

Also, the story of J. C. P. Williams himself presents an unsolved mystery:

Williams syndrome was first identified in 1961 by Dr. J. C. P. Williams of New Zealand. Williams, a cardiologist at Greenlane Hospital in Auckland, noticed that a number of the hospital’s young cardiac patients were small in stature, had elfin facial features and seemed friendly but in some ways were mentally slow. His published delineation of this syndrome put Dr. Williams on the map — off which he promptly and mysteriously fell. Twice offered a position at the prestigious Mayo Clinic in Rochester, Minn., he twice failed to show, disappearing the second time, in the late ’60s, from London, his last known location, with the only trace an unclaimed suitcase later found in a luggage office.

Wow, that's weird. I couldn't find any more details on the disappearance.

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Why, some of my best friends are younger siblings.

Doesn't that pretty much sum up the message of these two paragraphs in this NY Times article

Charles Darwin, author of the revolutionary "Origin of Species," was the fifth of six children. Nicolaus Copernicus, the Polish astronomer who determined that the Sun, not the Earth, was the center of the planetary system, grew up the youngest of four. René Descartes, the youngest of three, was a key figure in the scientific revolution of the 16th century.
First-borns have won more Nobel Prizes in science than younger siblings, but often by advancing current understanding, rather than overturning it, Dr. Sulloway argued. "It's the difference between every-year or every-decade creativity and every-century creativity," he said, "between creativity and radical innovation."

Or, "Sure, also-borns, you gave us Darwin and Descartes, but what have you done for us lately?"

I just wish that articles like this were illustrated along with the relevant distributions, showing not only the difference in means (in this case, 3 points) but also the standard deviations and overlap. That would be much more useful than these wiggle-paragraphs at the end.

Also, I wonder if there is some kind of biasing effect here, where parents are more likely to have successive offspring if their first one is healthier, aka smarter. I'll have to see the study to see if they control for this, but if not then the IQ loss in subsequent siblings may partly be regression to the mean.

UPDATE (6/22/2007): The analysis of children whose older siblings died might test for regression to the mean. Second-born children whose older sibling died tended to have IQs approximately the same as first-born children. So the interpretation is that the social rank of the child is the determining factor.

I say "might" because I'm not convinced this comparison tests for regression to the mean. We'd like to know what actual only children look like in comparison to first-borns of larger families. The Science paper doesn't specifically address the issue, but the comparison of first-born and second-born after death of first-born is very suggestive.

References:

Kristenen P, Bjerkedal T. 2007. Explaining the relation between birth older and intelligence. Science 316:1717. doi:10.1126/science.1141493

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Octopus minds

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

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Primate origins of morality

Nicholas Wade writes about primate behavior as a model for human morality. The article is mostly a profile of Frans de Waal's work.

Dr. de Waal sees human morality as having grown out of primate sociality, but with two extra levels of sophistication. People enforce their society's moral codes much more rigorously with rewards, punishments and reputation building. They also apply a degree of judgment and reason, for which there are no parallels in animals.
Religion can be seen as another special ingredient of human societies, though one that emerged thousands of years after morality, in Dr. de Waal's view. There are clear precursors of morality in nonhuman primates, but no precursors of religion. So it seems reasonable to assume that as humans evolved away from chimps, morality emerged first, followed by religion. "I look at religions as recent additions," he said. "Their function may have to do with social life, and enforcement of rules and giving a narrative to them, which is what religions really do."
As Dr. de Waal sees it, human morality may be severely limited by having evolved as a way of banding together against adversaries, with moral restraints being observed only toward the in group, not toward outsiders. "The profound irony is that our noblest achievement -- morality -- has evolutionary ties to our basest behavior -- warfare," he writes. "The sense of community required by the former was provided by the latter."

This is an interesting introduction to the topic, and -- for my Anthro 105 students -- it gives some detail about one of the reasons anthropologists study primate behavior. Several of de Waal's books reward reading on the topic -- the article mentions Priamtes and Philosophers, but I always recommend The Ape and the Sushi Master for its discussion of traditions and culture.

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Repressed memories in fact and fiction

The NY Times writer Benedict Carey has an interesting short article about research into repressed memories. There is a group of researchers who claim that the phenomenon is a cultural construct that emerged very recently:

In a paper posted online in the current issue of the journal Psychological Medicine, a team of psychiatrists and literary scholars reports that it could not find a single account of repressed memory, fictional or not, before the year 1800.
The researchers offered a $1,000 reward last March to anyone who could document such a case in a healthy, lucid person. They posted the challenge in newspapers and on 30 Web sites where the topic might be discussed. None of the responses were convincing, the authors wrote, suggesting that repressed memory is a "culture-bound syndrome" and not a natural process of human memory.

They're saying that the character Madame de Tourvel in Naturally, other researchers dispute the idea -- some even claim to have evidence from ancient Greek literature.

If I have an informed opinion, I've repressed it. But what I find interesting is the idea that a popular literary trends lead scientific research, sometimes to wrong results. It may be hard to rule out that something imagined in fiction could actually happen -- think of the number of people who have tried to find loopholes in special relativity that could lead to faster-than-light travel. There was no science fiction in 1800, but developing ideas about the mind provide their own equivalent.

We know that science can proceed along a false or misleading path for a long time when the cultural biases of the scientists lead research. Fictional plot devices are clever just insofar as people are willing to "suspend disbelief" about them -- which is a function of the readers' cultural biases. So the two combined might make for some interesting history!

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Greetings, meat machines, it's a New Year

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?

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Sherlock Holmes on the brain

I often refer to the "Sherlock Holmes" theory of the mind in my classes; in honor of finals week, I thought I would post the relevant passage from A Study in Scarlet:

"You see," he explained, "I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things so that he has a difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones."
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Risk assessment, part 1

Time has a short article describing the work of risk assessment expert John Adams.

The point, stresses Adams, is that drivers who feel safe may actually increase the risk that they pose to other drivers, bicyclists, pedestrians and their own passengers (while an average of 80% of drivers buckle up, only 68% of their rear-seat passengers do). And risk compensation is hardly confined to the act of driving a car. Think of a trapeze artist, suggests Adams, or a rock climber, motorcyclist or college kid on a hot date. Add some safety equipment to the equation -- a net, rope, helmet or a condom respectively -- and the person may try maneuvers that he or she would otherwise consider foolish. In the case of seat belts, instead of a simple, straightforward reduction in deaths, the end result is actually a more complicated redistribution of risk and fatalities. For the sake of argument, offers Adams, imagine how it might affect the behavior of drivers if a sharp stake were mounted in the middle of the steering wheel? Or if the bumper were packed with explosives. Perverse, yes, but it certainly provides a vivid example of how a perception of risk could modify behavior.

Adams makes two points:

(1) People who will tolerate a given level of risk will respond to an objective reduction in risk by doing riskier things. (Elsewhere, Adams calls this idea the "risk thermostat" model.)

(2) Risk is interactive and unequally distributed, so that decreasing the risks for one category of individuals may increase it for others.

Car accidents make pretty good illustrations for both. Some people who drive large SUVs feel a greater safety margin and therefore drive more aggressively. Providing these people with a "safer" driving platform tends to increase the risks for drivers of smaller cars. If these effects were strong enough, putting a "safer" class of vehicle on the road would actually increase the overall number of fatalities.

A web search for Adams' work brings up a technical report written for the Cato Institute, discussing risk perception in more detail. After a review of the effect of seat belt laws, he embarks on a discussion of risks identified through science. These kinds of risks are not directly accessible to the senses, and their magnitude can be appreciated only by studying large populations of things. The long-term risk of smoking is one example.

Before discussing these kinds of risks, Adams considers our attitudes toward risks that are accessible to the senses:

Directly perceptible risks are "managed" instinctively; our ability to cope with them has been built into us by evolution--contemplation of animal behavior suggests that it has evolved in nonhuman species as well. Our method of coping is also intuitive; we do not do a formal probabilistic risk assessment before we cross the street. There is now abundant evidence, particularly with respect to directly perceived risks on the road, that risk compensation accompanies the introduction of safety measures that do not reduce people's propensity to take risks. Statistics for death by accident and violence, perhaps the best available aggregate indicator of the way in which societies cope with directly perceived risk, display a stubborn resistance, over many decades, to the efforts of safety regulators to reduce them (Adams 1999:10).

Adams notes that much of the decrease in premature mortality during the past 150 years has been brought about by better understanding and communicating about invisible risks. The germ theory of disease is probably the most notable example.

But he points out the difficulty of measuring reductions in risk. At least, we can measure overall mortality rates -- if they decline after an intervention, then presumably it was effective. But activity-specific mortality rates won't do:

Moreover, risks can be displaced. If motorcycling were to be banned in Britain it would save about 500 lives a year. Or would it? If it could be assumed that all the banned motorcyclists would sit at home drinking tea, one could simply subtract motorcycle accident fatalities from the total annual road accident death toll. But at least some frustrated motorcyclists would buy old clunkers and try to drive them in a way that pumped as much adrenaline as their motorcycling did, and in a way likely to produce more kinetic energy to be dispersed if they crashed. The alternative risk-taking activities that they might pursue range from skydiving to glue sniffing, and there is no set of statistics that could prove that the country had been made safer, or more dangerous, by the ban (Adams 1999:20).

Now, I'm reading this because I'm evaluating strategies toward risk in human evolution. Mortality reductions are a major trend in the emergence of modern humans. That would tend to indicate an objective decrease in risks of various kinds.

But a decrease in mortality risk may not translate to an increase in fitness. For instance, if more adult males survive to older ages, they may prevent younger males from reproducing until they are older. If this happened, a reduction in mortality would impose a tradeoff of a reduction in fecundity for younger individuals. This tradeoff would not prevent the change, by any means -- in the transient after the appearance of a risk-reducing strategy, males who adopted the strategy would immediately have a fitness benefit. But the tradeoff itself might obscure the reasons for the change, or even suggest wrong hypotheses (for instance, the hypothesis that low fecundity for young males forced them to reduce their mortality risk).

Anyway, if professional statisticians are so bad at evaluating the risk landscape, evolutionary biologists are no better. Many evolutionary hypotheses deal explicitly in risks -- with increases in some risks being explained by declines in others. But if you have ever seen an attempt to quantify those risks in terms of fitness, you probably understand how shaky the foundations of such hypotheses can be.

This is the beginning of a multipart series on evolution and risk. There will be some math involved -- calculus, even! -- but at the end something very important will emerge. Risk is the hinge connecting the evolution of human life histories to the evolution of the human brain.

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A quick primer on bioaesthetics

It's not here, but at Brainethics, where Martin Skov has written up a short intro to the evolution of aesthetics with a booklist from the recent literature.

Neuroaesthetics can be thought of as a part of a more general study of art and aesthetics as a biological phenomenon. I will follow other proponents of this view (such as Tecumseh Fitch) in calling this broader approach bioaesthetics. The overall goal of bioaesthetics is to answer the three basic biological questions - what?, how?, why? - in regard to aesthetic behaviour in humans: what is art and aesthetics?; how does art and aesthetics spring from the brain?; and why did this cognitive ability evolve in humans? Neuroaesthetics is predominantly concerned with question number 2. In the list that follows below I will also mention a number of books that discuss the other two questions.

If you are one of my students and this area interests you, this is as good a list of recent books on the topic as you will find.

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Searle on Humphrey

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.

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Sixteen hours of pi

Earlier this week, a Japanese man recited the first 100,000 decimal digits of pi:

Akira Haraguchi, 60, needed more than 16 hours to recite the number to 100,000 decimal places, breaking his personal best of 83,431 digits set in 1995, his office said Wednesday. He made the attempt at a public hall in Kisarazu, just east of Tokyo.

As if to show just how difficult that would be, the ABC News story makes an obvious rounding error on digit four:

It is usually written out to a maximum of three decimal places, as 3.141, in math textbooks.

That would be one bad math textbook!

Anyway, this kind of extreme memory feat certainly shows the capability of some people to accommodate their minds to highly specialized information strings. Memorizing the complete works of Shakespeare, the full Koran and other long texts are other examples.

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Voodoo memories

For a little entertainment, and an interesting perspective on the nature of cognition and scientific reasoning, I suggest this clever essay by Jonah Lehrer of Seed:

[Emily] Pronin's experiment was simple: Harvard students were shown a voodoo doll and told that they were part of a study of "physical health symptoms that result from psychological factors...in the context of Haitian Voodoo." (In fact, dolls are not used in Haitian Voodoo but "they were used here to conform to participants' expectations about Voodoo practice.") Unbeknownst to the volunteers, the scientists had recruited a "confederate" as part of their experimental design. The confederate dressed and behaved normally with half of the participants - and very badly with the other half. He arrived late, tossed an extra copy of a consent form toward the trash can, but missed and left it on the floor. While the subjects read the voodoo death article, "he slowly rotated his pen on the tabletop, making a noise just noticeable enough to be grating." In other words, he acted like he deserved a hex.

You'll have to read it to see how it turned out.

It's an interesting study in the psychology of cause-and-effect, which figures not only into the area of scientific reasoning (as it is applied here) but also in the construction of memory.

A number of studies lately have focused on the way that people "fabulate" their memories. It seems that people don't remember the way things actually happened. Instead, they reconstruct a narrative about them based on the things that they do remember. Since these facts are often sketchy, the narrative begins to diverge from reality.

This phenomenon accounts for why different participants in an event usually remember it differently. It also lies at the root of the issue of false "recovered" memories -- since it can be easy to get someone to reconstruct events wrongly, yet vividly, by suggesting to them a few errant facts.

When people reconstruct the course of an event, they do so using knowledge and principles that their minds apply broadly to many kinds of things. In a sense, this process of constructing "causation" is one that is fundamental to our cognitive life. It works just to the extent that the causes we imagine are compatible with reality.

Is voodoo compatible? Well, in the experimental setup, there isn't a way to test whether the hex was real...

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Probably not a good idea

I was reading this Wired article about DARPA research on visual perception...

A new brain-computer-interface technology could turn our brains into automatic image-identifying machines that operate faster than human consciousness.
Researchers at Columbia University are combining the processing power of the human brain with computer vision to develop a novel device that will allow people to search through images ten times faster than they can on their own.

...and thinking, "Gee, wouldn't this be handy for research":

The brain emits a signal as soon as it sees something interesting, and that "aha" signal can be detected by an electroencephalogram, or EEG cap. While users sift through streaming images or video footage, the technology tags the images that elicit a signal, and ranks them in order of the strength of the neural signatures. Afterwards, the user can examine only the information that their brains identified as important, instead of wading through thousands of images.

You know, if it could automatically highlight interesting parts of papers. And then search through other papers for similar passages by keywords. And spring them all up on a really big screen. And put them all in the bibliography automatically.

Or maybe you'd just connect all the links to your own paper at the end, and call it a "brainiography".

Just think how insulted your colleagues would be if they didn't make it in!

I guess the next logical step would be tracking the "aha" signals for peer review...

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The past is before us, or behind, whatever

A recent paper in Cognitive Science by Nuñez and Sweetster has evoked several interesting strains of blog commentary. The paper is about the cognition of time as a function of conceptual metaphor with space.

That's pretty abtruse-sounding, and the Wikipedia entry on conceptual metaphor is fairly informative. The basic idea is that we may understand one class of relationships (a conceptual domain) in terms of the relationships that we know apply to another analogous domain.

All the talk about the new article seems to have come from the attention from a New York Times article, which is imprisoned behind TimesSelect, so I'll quote the interesting Savage Minds post instead:

The New York Times is running an article on a recent article in Cognitive Science by Nunez and Sweetser which demonstrates that Aymara speakers imagine the past to be in front of them and the future behind them -- reversed, in other words, from the spatial metaphors we use in English. The Times article notes "If they are right, this is bigger than anything the 60's tossed up. Is it possible that human concepts of time can vary this much because of language and culture? And what would it be like to think this way? Do I have the rest of my life behind me? And how can I let bygones be bygones if they're right in front of me?" Nunez and Sweetser also makes a to-do about the rarity of this pattern, since, it claims that "so far all documented languages appear to share a spatial metaphor mapping future events onto spatial locations in front of Ego and past events onto locations behind Ego."

The flavor of the SM comment is that cognitive scientists often ignore cultural variability that anthropologists hold as common knowledge:

Cognitive Science produce attention-grabbing headlines much more frequently than anthropologists, and this article is a prime example of how they manage to do so: ignorance.
Have Nunez and Sweetser actually conducted some sort of exhaustive examination of 'all documented languages'? No. In fact their citations reveal that they have examined a grand total of seven: English, Wolof, Chagga, Chinese, Japanese, Turkish, and American Sign Language (to be fair one of the articles they site has 'more cross cultural data').
If Nunez and Sweetser had looked a little bit further -- for example to the Pacific -- they would have found that these sorts of metaphors are quite common.

After the original post, there is a discussion in the comments at Savage Minds with links to elsewhere, including a Language Log entry on the paper:

I feel a need to address recent controversy regarding the uniqueness of the Aymara conceptualization of time-as-space. I cannot respond to everyone who says that their language of choice also has a "back to the future" metaphor, nor will I attempt to reconstruct all of the linguistic (metaphor-based) arguments involved. However, many of the objections that I have heard (and that I am sure the researchers of Aymara asked themselves) are based on a misconception that if a language has a single word that is polysemous between "front/past" or "back/future", then it automatically makes Aymara non-unique.

The short post then discusses why the Aymara case may be different from many others, which centers on the use of gesture as another communicative mode that redundantly includes the front:back::past:future axis.

Chris at Mixing Memory gives some commentary on the entire subject:

I've said it before, and I'll say it again: conceptual metaphor theory sucks. Why does it suck? Well, because there's no experimental evidence for it (and plenty of evidence against it). Except, that is, in one domain: time. Specifically, the work of Lera Boroditsky, along with Dedre Gentner and her colleagues, has provided interesting demonstrations of the influence of the way we talk about space on the way we conceptualize time. I've talked about their work before, and now Dave's talking about Gentner's work over at Cognitive Daily, so I won't go into a lot of detail. Instead, I'll give you an idea of what's going on with the time-space metaphors in their work, and then discuss some recent work by Rafael Nu–ez and his colleagues which introduces new types of time-space metaphors. The conclusion generally drawn from this work is that time is conceptualized metaphorically through mappings onto space. At the end of this post, I'm going to argue that no current evidence actually supports that position.

The critique involves the troublesome problems of irrelevant meanings and priming effects -- essentially, although languages may be constructed by applying metaphoric meanings to words, there is little evidence that the mind constructs concepts using these metaphors, and testing the cognitive treatment is very difficult considering the linguistic entanglements.

I don't particularly have any opinion, but it has been interesting reading much of these exchanges, which illuminate one present-day aspect of the Sapir-Whorf language-shaping-cognition paradigm.

References:

Nuñez RE, Sweetser E. 2006. With the future behind them: Convergent evidence from Aymara language and gesture in the crosslinguistic comparison of spatial construals of time. Cognitive Science 30:1-49. Abstract

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