October 27, 2008

Creationists Declare War Over The Brain

I received the latest copy of New Scientist magazine yesterday, and spotted this disturbing article in it which I have decided to post here. It seems to me that after being more or less defeated by the likes of the late Stephen Jay Gould, Steve Jones, Richard Dawkins, PZ Myers and other prominent evolutionary biologists on the subject of evolution, the IDiots are now turning their attention to the neurosciences. I cannot fully explain how disturbing to me this is as an up-and-coming neuroscientist. I feel a tad infuriated about it but I would be lying if I said I saw it coming. I had lulled myself into a false sense of security by thinking that evolution was the IDiot battleground, but perhaps it is the nature of grandiose 'conquerors' to move to pastures new. Perhaps I shall write up my own review of it soon, but for now here is the actual article. It can also be viewed online at the New Scientist site complete with links (all reproduced here):

"YOU cannot overestimate," thundered psychiatrist Jeffrey Schwartz, "how threatened the scientific establishment is by the fact that it now looks like the materialist paradigm is genuinely breaking down. You're gonna hear a lot in the next calendar year about... how Darwin's explanation of how human intelligence arose is the only scientific way of doing it... I'm asking us as a world community to go out there and tell the scientific establishment, enough is enough! Materialism needs to start fading away and non-materialist causation needs to be understood as part of natural reality."

His enthusiasm was met with much applause from the audience gathered at the UN's east Manhattan conference hall on 11 September for an international symposium called Beyond the Mind-Body Problem: New Paradigms in the Science of Consciousness. Earlier Mario Beauregard, a researcher in neuroscience at the University of Montreal, Canada, and co-author of The Spiritual Brain: A neuroscientist's case for the existence of the soul, told the audience that the "battle" between "maverick" scientists like himself and those who "believe the mind is what the brain does" is a "cultural war".

Schwartz and Beauregard are part of a growing "non-material neuroscience" movement. They are attempting to resurrect Cartesian dualism - the idea that brain and mind are two fundamentally different kinds of things, material and immaterial - in the hope that it will make room in science both for supernatural forces and for a soul. The two have signed the "Scientific dissent from Darwinism" petition, spearheaded by the Seattle-based Discovery Institute, headquarters of the intelligent design movement. ID argues that biological life is too complex to have arisen through evolution.

In August, the Discovery Institute ran its 2008 Insider's Briefing on Intelligent Design, at which Schwartz and Michael Egnor, a neurosurgeon at Stony Brook University in New York, were invited to speak. When two of the five main speakers at an ID meeting are neuroscientists, something is up. Could the next battleground in the ID movement's war on science be the brain?

Well, the movement certainly seems to hope that the study of consciousness will turn out to be "Darwinism's grave", as Denyse O'Leary, co-author with Beauregard of The Spiritual Brain, put it. According to proponents of ID, the "hard problem" of consciousness - how our subjective experiences arise from the objective world of neurons - is the Achilles heel not just of Darwinism but of scientific materialism. This fits with the Discovery Institute's mission as outlined in its "wedge document", which seeks "nothing less than the overthrow of materialism and its cultural legacies", to replace the scientific world view with a Christian one.

Now the institute is funding research into "non-material neuroscience". One recipient of its cash is Angus Menuge, a philosophy professor at Concordia University, Wisconsin, a Christian college, who testified in favour of teaching ID in state-funded high-schools at the 2005 "evolution hearings" in Kansas. Using a Discovery Institute grant, Menuge wrote Agents Under Fire, in which he argued that human cognitive capacities "require some non-natural explanation". In June, James Porter Moreland, a professor at the Talbot School of Theology near Los Angeles and a Discovery Institute fellow, fanned the flames with Consciousness and the Existence of God. "I've been doing a lot of thinking about consciousness," he writes, "and how it might contribute to evidence for the existence of God in light of metaphysical naturalism's failure to provide a helpful explanation." Non-materialist neuroscience provided him with this helpful explanation: since God "is" consciousness, "the theist has no need to explain how consciousness can come from materials bereft of it. Consciousness is there from the beginning."

To properly support dualism, however, non-materialist neuroscientists must show the mind is something other than just a material brain. To do so, they look to some of their favourite experiments, such as research by Schwartz in the 1990s on people suffering from obsessive-compulsive disorder. Schwartz used scanning technology to look at the neural patterns thought to be responsible for OCD. Then he had patients use "mindful attention" to actively change their thought processes, and this showed up in the brain scans: patients could alter their patterns of neural firing at will.

From such experiments, Schwartz and others argue that since the mind can change the brain, the mind must be something other than the brain, something non-material. In fact, these experiments are entirely consistent with mainstream neurology - the material brain is changing the material brain. But William Dembski, one of ID's founding fathers and a senior fellow at the Discovery Institute, praised Schwartz's work as providing "theoretical support for the irreducibility of mind to brain". Dembski's website shows that he is currently co-editing The End of Materialism with Schwartz and Beauregard. Meanwhile, Schwartz has been working with Henry Stapp, a physicist at the US Department of Energy's Lawrence Berkeley National Laboratory, who also spoke at the symposium. They have been developing non-standard interpretations of quantum mechanics to explain how the "non-material mind" affects the physical brain.

Clearly, while there is a genuine attempt to appropriate neuroscience, it will not influence US laws or education in the way that anti-evolution campaigns can because neuroscience is not taught as part of the core curriculum in state-funded schools. But as Andy Clark, professor of logic and metaphysics at the University of Edinburgh, UK, emphasises: "This is real and dangerous and coming our way."

He and others worry because scientists have yet to crack the great mystery of how consciousness could emerge from firing neurons. "Progress in science is slow on many fronts," says John Searle, a philosopher at the University of California, Berkeley. "We don't yet have a cure for cancer, but that doesn't mean cancer has spiritual causes." And for Patricia Churchland, a philosopher of neuroscience at the University of California, San Diego, "it is an argument from ignorance. The fact something isn't currently explained doesn't mean it will never be explained or that we need to completely change not only our neuroscience but our physics."

The attack on materialism proposes to do just that, but it all turns on definitions. "At one time it looked like all physical causation was push/pull Newtonianism," says Owen Flanagan, professor of philosophy and neurobiology at Duke University, North Carolina. "Now we have a new understanding of physics. What counts as material has changed. Some respectable philosophers think that we might have to posit sentience as a fundamental force of nature or use quantum gravity to understand consciousness. These stretch beyond the bounds of what we today call 'material', and we haven't discovered everything about nature yet. But what we do discover will be natural, not supernatural."

And as Clark observes: "This is an especially nasty mind-virus because it piggybacks on some otherwise reasonable thoughts and worries. Proponents make such potentially reasonable points as 'Oh look, we can change our brains just by changing our minds,' but then leap to the claim that mind must be distinct and not materially based. That doesn't follow at all. There's nothing odd about minds changing brains if mental states are brain states: that's just brains changing brains."

That is the voice of mainstream academia. Public perception, however, is a different story. If people can be swayed by ID, despite the vast amount of solid evidence for evolution, how hard will it be when the science appears fuzzier?

What can scientists do? They have been criticised for not doing enough to teach the public about evolution. Maybe now they need a big pre-emptive push to engage people with the science of the brain - and help the public appreciate that the brain is no place to invoke the "God of the gaps".

October 13, 2008

Why Are Some People Black?

As a follow-up of sorts to the last post on evolution, an excellent article by Steve Jones from the same book discusses the reasons for why evolution results in different skin complexions. It was written around 1996 or so.


Everyone knows - do they not? - that many people have black skin. What is more, black people are concentrated in certain places - most notably, in Africa - and, until the upheavals of the past few centuries, they were rare in Europe, Asia, and the Americas. Why should this be so? It seems a simple question. Surely, it we cannot give a simple answer, there is something wrong with our understanding of ourselves. In fact, there is no straightforward explanation of this striking fact about humankind. Its absence says a lot about the strengths and weaknesses of the theory of evolution and of what science can and cannot say about the past. Any anatomy book gives one explanation of why people look different. Doctors love pompous words, particularly if they refer to other doctors who lived long ago. Black people have black skin, their textbooks say, because they have a distinctive Malphigian layer. This is a section of the skin named after the seventeenth-century Italian anatomist Malphigii. It contains lots of cells called melanocytes. Within them is a dark pigment called melanin. The more there is, the blacker the skin. Malphigii found that African skin had more melanin than did that of Europeans. The question was, it seemed, solved.

This is an example of what I sometimes think of as 'the Piccadilly explanation.' One of the main roads in London is called Piccadilly - an oddly un-English word. I have an amusing book that explains how London's streets got their names. What it says about Piccadilly sums up the weakness of explanations that depend, like the anatomists', only on describing a problem in more detail. The street is named, it says, after the tailors who once lived there and made high collars called piccadills. Well, fair enough; but surely that leaves the interesting question unanswered. Why call a collar a piccadill in the first place? It is not an obvious word for an everyday piece of clothing. My book is, alas, silent.

Malphigii's explanation may be good enough for doctors, but will not satisfy any thinking person. It answers the question how but not the more interesting question why there is more melanin in African skin.

Because the parents, grandparents, and - presumably - distant ancestors of black people are black, and those of white people are white, the solution must lie in the past. And that is a difficulty for the scientific method. It is impossible to check directly just what was going on when the first blacks appeared on earth. Instead, we must rely on indirect evidence. There is one theory that is, if nothing else, simple and consistent. It has been arrived at again and again. It depends solely on belief; and if there is belief, the question of proof does not arise. Because of this, the theory lies outside science.

It is that each group was separately created by divine action. The Judeo-Christian version has it that Adam and Eve were created in the Garden of Eden. Later, there was a gigantic flood; only one couple, the Noahs, survived. They had children: Ham, Shem, and Japheth. Each gave rise to a distinct branch of the human race, Shem to the Semites, for example. The children of Ham had dark skins. From them sprang the peoples of Africa. That, to many people, is enough to answer the question posed in this essay.

The Noah story is just a bald statement about history. Some creation myths are closer to science. They try to explain why people look different. One African version is that God formed men from clay, breathing life into his creation after it had been baked. Only the Africans were fully cooked - they were black. Europeans were not quite finished and were an unsatisfactory muddy pink. The trouble with such ideas is that they cannot be disproved. I get lots of letters from people who believe passionately that life, in all its diversity, appeared on earth just a few thousand years ago as a direct result of God's intervention. There is no testimony that can persuade the otherwise. Prove that there were dinosaurs millions of years before humans, and they come up with rock 'footprints' showing, they say, that men and dinosaurs lived together as friends. So convinced are they of the truth that they insist that their views appear in school textbooks.

If all evidence, whatever it is, can only be interpreted as supporting one theory, then there is no point in arguing. In fact, if belief in the theory is strong enough, there is no point in looking for evidence in the first place. Certainty is what blocked science for centuries. Scientists are, if nothing else, uncertain. Their ideas must constantly be tested against new knowledge. If they fail the test, they are rejected.

No biologist now believes that humans were created through some miraculous act. All are convinced that they evolved from earlier forms of life. Although the proof of the fact of evolution is overwhelming, there is plenty of room for controversy about how it happened. Nowhere is this clearer than in the debate about skin colour.

Modern evolutionary biology began with the nineteenth-century English biologist Charles Darwin. He formed his ideas after studying geology. In his day, many people assumed that grand features such as mountain ranges or deep valleys could arise only through sudden catastrophes such as earthquakes or volcanic eruptions, which were unlikely to be seen by scientists as they were so rare. Darwin realised that, given enough time, even a small stream can, by gradually wearing away the rocks, carve a deep canyon. The present, he said, is the key to the past. By looking at what is going on in a landscape today. It is possible to infer the events of millions of years ago. In the same way, the study of living creatures can show what happened in evolution.

In The Origin of Species, published in 1859, Darwin suggested a mechanism whereby new forms of life could evolve. Descent with modification, as he called it, is a simple piece of machinery, with two main parts. One produces inherited diversity. This process is now known as mutation. In each generation, there is a small but noticeable chance of a mistake in copying genes as sperm or eggs are made. Sometimes we can see the results of mutations in skin colour; one person in several thousand is an albino, lacking all skin pigment. Albinos are found all over the world, including Africa. They descend from sperm or eggs that have suffered damage in the pigment genes. The second piece of the machine is a filter. It separates mutations which are good at coping with what the environment throws at them from those which are not. Most mutations - albinism, for example - are harmful. The people who carry mutant genes are less likely to survive and to have children than do those who do not. Such mutations quickly disappear. Sometimes, though, one turns up which is better at handling life's hardships than what went before. Perhaps the environment is changing, or perhaps the altered gene does its job better. Those who inherit it are more likely to survive; they have more children, and the gene becomes more common. By this simple mechanism, the population has evolved through natural selection. Evolution, thought Darwin, was a series of successful mistakes.

If Darwin's machine worked for long enough, then new forms of life - new species - would appear. Given enough time, all life's diversity could emerge from simple ancestors. There was no need to conjure up ancient and unique events (such as a single incident of creation) which could neither be studied nor duplicated. Instead, the living world was itself evidence for the workings of evolution. What does Darwin's machine tell us about skin colour? As so often in biology, what we have is a series of intriguing clues, rather than a complete explanation.

There are several kinds of evidence about how things evolve. The best is from fossils; the preserved remnants of ancient times. These contain within themselves a statement of their age. The chemical composition of bones (or of the rocks into which they are transformed) shifts with time. The molecules decay at a known rate, and certain radioactive substances change from one form into another. This gives a clue as to when the original owner of the bones died. It may be possible to trace the history of a family of extinct creatures in the changes that occur as new fossils succeed old.

The human fossil record is not good - much worse, for example, than that of horses. In spite of some enormous gaps, enough survives to make it clear that creatures looking not too different from ourselves first appeared around a hundred and fifty thousand years ago. Long before that, there were apelike animals which looked noticeably human but would not be accepted as belonging to our own species if they were alive today. No one has traced an uninterrupted connection between these extinct animals and ourselves. Nevertheless, the evidence for ancient creatures that changed into modern humans is overwhelming. As there are no fossilised human skins, fossils say nothing directly about skin colour. They do show that the first modern humans appeared in Africa. Modern Africans are black. Perhaps, then, black skin evolved before white. Those parts of the world in which people have light skins - northern Europe, for example - were not populated until about a hundred thousand years ago, so that white skin evolved quite quickly. Darwin suggested another way of inferring what happened in the past: to compare creatures living today. If two species share a similar anatomy, they probably split from a common ancestor more recently than did another which has a different body plan. Sometimes it is possible to guess at the structure of an extinct creature by looking at its living descendants. This approach can be used not just for bones but for molecules such as DNA. Many biologists believe that DNA evolves at a regular rate; that in each generation, a small but predictable proportion of its subunits changes from one form into another. If this is true (and often it is), then counting the changes between two species reveals how closely they are related. What is more, if they share an ancestor that has been dated using fossils, it allows DNA to be used as a 'molecular clock,' timing the speed of evolution. The rate at which the clock ticks can then be used to work out when other species split by comparing their DNA, even if no fossils are available.

Chimpanzees and gorillas seem, from their body plan, to be our relatives. Their genes suggest the same thing. In fact, each shares 98 percent of its DNA with ourselves, showing just how recently we separated. The clock suggests that the split was about six million years ago. Both chimp and gorilla have black skins. This, too, suggests that the first humans were black and that white skin evolved later. However, it does not explain why white skin evolved. The only hint from fossils and chimps is that the change took place when humans moved away from the tropics. We are, without doubt, basically tropical animals. It is much harder for men and women to deal with cold than with heat. Perhaps climate has something to do with skin colour. To check this idea, we must, like Darwin, look at living creatures. Why should black skin be favoured in hot and sunny places and white where it is cool and cloudy? It is easy to come up with theories, some of which sound pretty convincing. However, it is much harder to test them.

The most obvious idea is wrong. It is that black skin protects against heat. Anyone who sits on a black iron bench on a hot sunny day soon discovers that black objects heat up more than white ones do when exposed to the sun. This is because they absorb more solar energy. The sun rules the lives of many creatures. Lizards shuttle back and forth between sun and shade. In the California desert, if they stray more than six feet from shelter on a hot day, they die of heat stroke before they can get back. African savannahs are dead places at noon, when most animals are hiding in the shade because they cannot cope with the sun. In many creatures, populations from hot places are lighter - not darker - in colour to reduce the absorption of solar energy. People, too, find it hard to tolerate full sunshine - blacks more so than whites. Black skin does not protect those who bear it from the sun's heat. Instead, it makes the problem worse. However, with a bit of ingenuity, it is possible to bend the theory slightly to make it fit. Perhaps it pays to have black skin in the chill of the African dawn, when people begin to warm up after a night's sleep. In the blaze of noon, one can always find shelter under a tree.

The sun's rays are powerful things. They damage the skin. Melanin helps to combat this. One of the first signs of injury is an unhealthy tan. The skin is laying down an emergency layer of melanin pigment. Those with fair skin are at much greater risk from skin cancer than are those with dark. The disease reaches its peak in Queensland, in Australia, where fair-skinned people expose themselves to a powerful sun by lying on the beach. Surely, this is why black skin is common in sunny places - but, once again, a little thought shows that it probably is not. Malignant melanoma, the most dangerous skin cancer, may be a vicious disease, but it is an affliction of middle age. It kills its victims after they have passed on their skin-colour genes to their children. Natural selection is much more effective if it kills early in life. If children fail the survival test, then their genes perish with their carriers. The death of an old person is irrelevant, as their genes (for skin colour or anything else) have already been handed on to the next generation.

The skin is an organ in its own right, doing many surprising things. One is to synthesise vitamin D. Without this, children suffer from rickets: soft, flexible bones. We get most vitamins (essential chemicals needed in minute amounts) from food. Vitamin D is unusual. It can be made in the skin by the action of sunlight on a natural body chemical. To do this, the sun must get into the body. Black people in sunshine hence make much less vitamin D than do those with fair skins. Vitamin D is particularly important for children, which is why babies (African or European) are lighter in colour than are adults. Presumably, then, genes for relatively light skin were favoured during the spread from Africa into the cloud and rain of the north. That might explain why Europeans are white - but does it reveal why Africans are black? Too much vitamin D is dangerous (as some people who take vitamin pills discover to their cost). However, even the fairest skin cannot make enough to cause harm. The role of black skin is not to protect against excess vitamin D.

It may, though, be important in preserving other vitamins. The blood travels around the body every few minutes. On the way, it passes near the surface of the skin through fine blood vessels. There, it is exposed to the damaging effects of the sun. The rays destroy vitamins - so much so, that a keen blond sunbather is in danger of vitamin deficiency. Even worse, the penetrating sunlight damages antibodies, the defensive proteins made by the immune system. In Africa, where infections are common and, sometimes, food is short, vitamin balance and the immune system are already under strain. The burden imposed by penetrating sunlight may be enough to tip the balance between health and disease. Dark skin pigmentation may be essential for survival. No one has yet shown directly whether this is true.

There are plenty of other theories as to why some people are black. For an African escaping from the sun under a tree, black skin is a perfect camouflage. Sexual preference might even have something to do with the evolution of skin colour. If, for one reasons or another, people choose their partners on the basis of colour, then the most attractive genes will be passed on more effectively. A slight (and perhaps quite accidental) preference for dark skin in Africa and light in Europe would be enough to do the job, This kind of thing certainly goes on with peacocks - in which females prefer males with brightly patterned tails - but there is no evidence that it happens in humans. Accident might be important in another way, too. Probably only a few people escaped from Africa a hundred thousand years and more ago. If, by chance, some of them carried genes for relatively light skins, then part of the difference in appearance between Africans and their northern descendants results from a simple fluke. There is a village of North American Indians today where albinos are common. By chance, one of the small number of people who founded the community long ago carried the albino mutation and it is still abundant there.

All this apparent confusion shows how difficult it is for science to reconstruct history. Science is supposed to be about testing, and perhaps disproving, hypotheses. As we have seen, there is no shortage of ideas about why people differ in skin colour. Perhaps none of the theories is correct, or perhaps one, two, or all of them are. Because whatever gave rise to the differences in skin colour in different parts of the world happened long ago, no one can check directly. But science does not always need direct experimental tests. A series of indirect clues may be almost as good. The hints that humans evolved from simpler predecessors and are related to other creatures alive today are so persuasive that it is impossible to ignore them. So far, we have too few facts and too many opinions to be certain of all the details of our own evolutionary past. However, the history of the study of evolution makes me confident that, some day, the series of hints outlined in this essay will suddenly turn into a convincing proof of just why some people are black and some white.

October 10, 2008

Three Facets of Evolution

I'd like to put up this excellent short piece by the late Stephen Jay Gould, the renowned palaeontologist and evolutionary biologist. It was originally published in How Things Are: A Science Toolkit for the Mind by John & Katinka Brockman (1996), and it outlines evolution theory and the bare basics of how to deal with some of the current controversies.


Three Facets of Evolution

§ - What Evolution Is Not.

Of all the fundamental concepts in the life sciences, evolution is both the most important and the most widely misunderstood. Since we often grasp a subject best by recognising what it isn't, and what it cannot do, we should begin with some disclaimers, acknowledging for science what G. K. Chesterton considered so important for the humanities: 'Art is limitation; the essence of every picture is the frame.'

First, neither evolution, nor any science, can access the subject of ultimate origins and ethical meanings. (Science, as an enterprise, tries to discover and explain the phenomena and regularities of the empirical world, under the assumption that natural laws are uniform in space and time. This restriction places an endless world of fascination within the 'picture'; most subjects thus relegated to the 'frame' are unanswerable in any case.) Thus, evolution is not the study of life's ultimate origin in the universe or of life's intrinsic significance among nature's objects; these questions are philosophical (or theological) and do not fall within the purview of science. (I also suspect that they have no universally satisfactory answers, but this is another subject for another time.) This point is important because zealous fundamentalists, masquerading as 'scientific creationists,' claim that creation must be equated with evolution, and be given equal time in schools, because both are equally 'religious' in dealing with ultimate unknowns. In fact, evolution does not treat such subjects at all, and thus remains fully scientific.

Second, evolution has been saddled with a suite of concepts and meanings that represent long-standing Western social prejudices and psychological hopes, rather than any account of nature's factuality. Such 'baggage' may be unavoidable for any field so closely allied with such deep human concerns (see Part 3 of this statement), but this strong social overlay has prevented us from truly completing Darwin's revolution. Most pernicious and constraining among these prejudices is the concept of progress, the idea that evolution possesses a driving force of manifests an overarching trend towards increasing complexity, better biomechanical design, bigger brains, or some other parochial definition of progress centered upon a long-standing human desire to place ourselves atop nature's pile - and thereby assert a natural right to rule and exploit our planet.

Evolution, in Darwin's formation, is adaptation to changing local environments, not universal 'progress.' A lineage of elephants that evolves a heavier coating of hair to become a woolly mammoth as the ice sheets advance does not become a superior elephant in any general sense, but just an elephant better adapted to local conditions of increasing cold. For every species that does become more complex as an adaptation to its own environment, look for parasites (often several species) living within its body - for parasites are usually greatly simplified in anatomy compared with their freeliving ancestors, yet these parasites are as well adapted to the internal environment of their host as the host has evolved to match the needs of its external environment.

§ What Evolution Is.

In its minimalist, 'bare bones' formulation, evolution is a simple idea with a remarkable range of implications. The basic claim includes two linked statements that provide rationales for the two central disciplines of natural history: taxonomy (or the order of relationships among organisms), and palaeontology (or the history of life). Evolution means (1) that all organisms are related by ties of genealogy or descent from common ancestry along the branching patterns of life's tree, and (2) that lineages alter their form and diversity through time by a natural process of change - 'descent with modification' in Darwin's chosen phrase. This simple, yet profound, insight immediately answers the great biological question of the ages: What is the basis for the 'natural system' of relationships among organisms (cats closer to dogs than to lizards; all vertebrates closer to each other than any to an insect - a fact well appreciated, and regarded as both wonderful and mysterious, long before evolution provided the reason). Previous explanations were unsatisfactory because they were either untestable (God's creative hand making each species by fiat, with taxonomic relationships representing the order of divine thought), or arcane and complex (species as natural places, like chemical elements in the periodic table, for the arrangement of organic matter). Evolution's explanation for the natural system is so stunningly simple: Relationship is genealogy; humans are like apes because we share such a recent common ancestor. The taxonomic order is a record of history.

But the basic fact of genealogy and change - descent with modification - is not enough to characterise evolution as a science. For science has two missions: (1) to record and discover the factual state of the empirical world, and (2) to devise and test explanations for why the world works as it does. Genealogy and change only represent the solution to this first goal - a description of the fact of evolution. We also need to know the mechanism by which evolutionary change occurs - the second goal of explaining the causes of descent with modification. Darwin proposed the most famous and best-documented mechanism for change in the principle that he named 'natural selection.'

The fact of evolution is as well documented as anything we know in science - as secure as our conviction that Earth revolves about the sun, and not vice versa. The mechanism of evolution remains a subject of exciting controversy - and science is most lively and fruitful when engaged in fundamental debates about the causes of well-documented facts. Darwin's natural selection has been affirmed, in studies both copious and elegant, as a powerful mechanism, particularly in evolving the adaptations of organisms to their local environments - what Darwin called 'that perfection of structure and coadaptation which most justly excites our admiration.' But the broad-scale history of life includes other phenomena that may require different kinds of causes as well (potentially random effects, for example, in another fundamental determinant of life's pattern - which groups live, and which die, in episodes of catastrophic extinction).

§ Why Should We Care?

The deepest, in-the-gut, answer to the question lies in the human psyche, and for reasons that I cannot begin to fathom. We are fascinated by physical ties of ancestry; we feel that we will understand ourselves better, know who we are in some fundamental sense, when we trace the sources of our descent. We haunt graveyards and parish records; we pore over family Bibles and search out elderly relatives, all to fill in the blanks on our family tree. Evolution is this same phenomenon on a much more inclusive scale - roots writ large. Evolution is the family tree of our races, species, and lineages - not just of our little, local surname. Evolution answers, insofar as science can address such questions at all, the troubling and fascinating issues of 'Who are we?' 'To which other creatures are we related, and how?' 'What is the history of our interdependency with the natural world?' 'Why are we here at all?'

Beyond this, I think that the importance of evolution in human thought is best captured in a famous statement by Sigmund Freud, who observed, with wry and telling irony, that all great scientific revolutions have but one feature in common: the casting of human arrogance off one pedestal after another of previous convictions about our ruling capacity in the universe. Freud mentions three such revolutions: the Copernican, for moving our home from center stage in a small universe to a tiny peripheral hunk of rock amid inconceivable vastness; the Darwinian, for 'relegating us to descent from an animal world'; and (in one of the least modest statements of intellectual history) his own, for discovering the unconscious and illustrating the nonrationality of the human mind. What can be more humbling, and therefore more liberating, than a transition from viewing ourselves as 'just a little lower than the angels,' the created rulers of nature, made in God's image to shape and subdue the earth - to the knowledge that we are not only natural products of a universal process of descent with modification (and thus kin to all other creatures), but also a small, late-blooming, and ultimately transient twig on the copiously arborescent tree of life, and not the foreordained summit of a ladder of progress. Shake complacent certainty, and kindle the fire of intellect.

October 5, 2008

Brain Basics!

An excellent article by Michael Craig Miller M.D. that I found in Newsweek that serves as a basic introduction into the false mind-brain dichotomy and other issues:

The brain is the mind is the brain. One hundred billion nerve cells, give or take, none of which individually has the capacity to feel or to reason, yet together generating consciousness. For about 400 years, following the ideas of French philosopher René Descartes, those who thought about its nature considered the mind related to the body, but separate from it. In this model—often called “dualism” or the mind-body problem—the mind was “immaterial,” not anchored in anything physical. Today neuroscientists are finding abundant evidence of an idea that even Freud played with more than 100 years ago, that separating mind from brain makes no sense. Nobel Prize-winning psychiatrist-neuroscientist Eric Kandel stated it directly in a watershed paper published in 1998: “All mental processes, even the most complex psychological processes, derive from operations of the brain.”

Neuroscientists consider it settled that the mind arises from the cooperation of billions of interconnected cells that, individually, are no smarter than amoebae. But it’s a shocking idea to some that the human mind could arise out of such an array of mindlessness. Many express amazement that emotions, pain, sexual feelings or religious belief could be a product of brain function. They are put off by the notion that such rich experiences could be reduced to mechanical or chemical bits. Or they worry that scientific explanations may seduce people into a kind of moral laziness that provides a ready excuse for any human failing: “My brain made me do it.” Our brains indeed do make us do it, but that is nonetheless consistent with meaningful lives and moral choices. Writing for the President’s Council on Bioethics earlier this year, philosopher Daniel Dennett made the point that building knowledge about the biology of mental life may improve our decision making, even our moral decision making. And it could enhance our chances of survival as a species, too.

Your heart, lungs, kidneys and digestive tract keep you alive. But your brain is where you live. The brain is responsible for most of what you care about—language, creativity, imagination, empathy and morality. And it is the repository of all that you feel. The endeavor to discovery the biological basis for these complex human experiences has given rise to a relatively new discipline: cognitive neuroscience. It has recently exploded as a field, thanks, in part, to decades of advances in neuroimaging technology that enable us to see the brain at work. As Dr. Joel Yager, professor of psychiatry at the University of Colorado, has said, “We can now watch the mind boggle!”

Certainly, you won’t find an entry for “mind-boggling” in the index of a modern neuroscience textbook. You will also have a hard time finding the words “happiness” or “sadness,” “anger” or “love.” Neuroscientists do, however, have a rapidly growing appreciation of the emotional brain and are beginning to look closely at these subjective states, which were formerly the province of philosophers and poets. It is complex science that holds great promise for improving the quality of life. Fortunately, understanding basic principles does not require an advanced degree.

Fear Itself
Fear is a good place to start, because it is one of the emotions that cognitive neuroscientists understand well. It is an unpleasant feeling, but necessary to our survival; humans would not have lasted very long in the wilderness without it. Two deep brain structures called the amygdalae manage the important task of learning and remembering what you should be afraid of.

Each amygdala, a cluster of nerve cells named after its almond shape (from the Greek amugdale), sits under its corresponding temporal lobe on either side of the brain. Like a network hub, it coordinates information from several sources. It collects input from the environment, registers emotional significance and—when necessary—mobilizes a proper response. It gets information about the body’s response to the environment (for example, heart rate and blood pressure) from the hypothalamus. It communicates with the reasoning areas in the front of the brain. And it connects with the hippocampus, an important memory center.

The fear system is extraordinarily efficient. It is so efficient that you don’t need to consciously register what is happening for the brain to kick off a response. If a car swerves into your lane of traffic, you will feel the fear before you understand it. Signals travel between the amygdala and your crisis system before the visual part of your brain has a chance to “see.” Organisms with slower responses probably did not get the opportunity to pass their genetic material along. Fear is contagious because the amygdala helps people not only recognize fear in the faces of others, but also to automatically scan for it. People or animals with damage to the amygdala lose these skills. Not only is the world more dangerous for them, the texture of life is ironed out; the world seems less compelling to them because their “excitement” anatomy is impaired.

Anger Management
Until recently, there was relatively little research showing how the brain processes anger. But that has begun to change. Recent studies indicate that anger may trigger activity in a part of the brain not named as poetically as the amygdala—the dorsal anterior cingulate cortex (abbreviated dACC). Like the amygdala, the dACC’s function makes sense, given its connections to areas of the brain involved in recognizing an offense (he just stole my iPod), registering a feeling (I’m angry) and acting on it (I’m going to …). It also links to the reasoning centers in the front part of the brain, as well as memory centers, which play a role in angry rumination or stewing after the fact.

Researchers, however, have been more focused on one of the consequences of anger—aggression—probably because it can be observed through behavior. It’s known, for example, that men are overtly more aggressive than women because of differences in male and female hormones. But the brains of men and women are also different, and some of those differences may affect aggression. In the front of the brain, the orbitofrontal cortex is recruited to help make decisions and temper emotional responses. It lights up when people are making judgments. Adrian Raine and colleagues at the University of Southern California note that, on average, men have a lower volume of gray matter (the bodies of nerve cells) in the orbitofrontal cortex than women. According to their analysis, this brain difference accounts for a healthy portion of the gender gap seen in the frequency of antisocial behavior.

Even a neuroscientist can see that murder and mayhem are undesirable. But a neuroscientist can also see why that trait might still be in the gene pool. The gene for sickle cell anemia survived because it provided protection against another disease, malaria. Similarly, aggression is often an advantage. Until recently in historical terms, a readiness to fight and the ability to kill was a way to consolidate control over resources for survival. Fortunately, diplomats have also evolved. Some of our ancestors who understood that aggression carried risks as well as advantages used their creative human brains to devise better solutions for resolving conflicts. Our predecessors also originated symbolic diversions for aggression, like sports and chess.

So Happy (and Sad) Together
The common emotions of sadness and happiness are a problem for researchers. Depression and mania are core areas of study for a neuroscientist. But everyday ups and downs are so broadly defined that researchers have a hard time figuring out what exactly to study. They note activity in virtually every part of the brain. Last year Drs. Peter J. Freed and J. John Mann, publishing in The American Journal of Psychiatry, reported on the literature of sadness and the brain. In 22 studies, brain scans were performed on nondepressed but sad volunteers. Sadness was mostly induced (subjects were shown sad pictures or films, asked to remember a sad event), although, in a couple of studies, subjects had recently experienced a loss. In the aggregate, sadness appeared to cause altered activity in more than 70 different brain regions. The amygdala and hippocampus both show up on this list, as do the front part of the brain (prefrontal cortex) and the anterior cingulate cortex. A structure called the insula (which means “island") also appears here—it is a small region of cortex beneath the temporal lobes that registers body perceptions and taste.

The authors believe this complicated picture makes sense. The brain regions on their list process conflict, pain, social isolation, memory, reward, attention, body sensations, decision making and emotional displays, all of which can contribute to feeling sad. Sadness triggers also vary—for example, the memory of a personal loss; a friend stressing over a work conflict; seeing a desolate film.

In the brain, happiness is as widely distributed as sadness. In his book “This Is Your Brain on Music,” Dr. Daniel Levitin (page 58) notes that music simultaneously enlists many parts of the brain. We listen and respond to sounds and rhythms (auditory, sensory and motor cortex, cerebellum). We interpret (sensory cortex) and reason (prefrontal cortex). Music pulls on memories for experience and emotion (amygdala and hippocampus). If the music is working for you, it is probably triggering the reward system (nucleus accumbens). And if you’re playing it, as Dr. Levitin does, you also get to throw satisfaction into the mix. This may or may not be a description of happiness, but it certainly coincides with the notion of flow, described by the author Dr. Mihály Csíkszentmihályi: concentrated attention and the absence of self-consciousness. A neuroscientist might say that a life that fully engages your brain in these ways is a life worth living.

Faith, Love and Understanding
The challenge to cognitive neuroscientists becomes greater as we go up the ladder to more-complicated emotional states. And the stakes become higher, too, because research into such highly valued and personal mental processes can be easily misunderstood.

Empathy is more than being nice. It is the ability to feel what another person feels, and in its most refined form it is the capacity to deeply understand another person’s point of view. The brain’s empathic powers actually begin with fear detection. Most of us are extraordinarily skilled face readers. We readily act on the emotions communicated to us through facial expression. And the grammar of facial expression, in some instances, is plain. We are masters at telling when a smile is insincere by the absence of wrinkles (called Duchenne lines) around the smiler’s eyes. In a spontaneous smile, the corners of the mouth curl up and muscles around the eyes contract. Duchenne lines are almost impossible to fake.

In the Marx Brothers movie “Duck Soup,” Groucho encounters his brother Chico in a doorway, dressed like him in a nightshirt and cap and a fake mustache. They perform a famous version of the mirror routine, Chico copying Groucho’s actions. The humor may derive, at least in part, from humans’ highly developed skill as copycats. When you observe someone eating ice cream or stubbing a toe, the brain regions that are activated in the eater and the stubber are also activated in you.

But empathy depends on more than an ability to mirror actions or sensations. It also requires what some cognitive neuroscientists call mentalizing, or a “theory of mind.” Simon Baron-Cohen, a leading researcher in the study of autism, has identified the inability to generate a theory of mind as a central deficit in that illness. He has coined the term “mindblindness” to designate that problem. The corollary, “mindsightedness,” requires healthy function in several areas of the brain. The processing and remembering of subtle language cues take place toward the ends of the temporal lobes. At the junction of the temporal and parietal lobes, the brain handles memory for events, moral judgment and biological motion (what we might call body language). And the prefrontal cortex handles many complex reasoning functions involved in feelings of empathy.

Not surprisingly, love also engages a whole lot of brain. Areas that are deeply involved include the insula, anterior cingulate, hippocampus and nucleus accumbens— in other words, parts of the brain that involve body and emotional perception, memory and reward. There is also an increase in neurotransmitter activity along circuits governing attachment and bonding, as well as reward (there’s that word again). And there’s scientific evidence that love really is blind; romantic love turns down or shuts off activity in the reasoning part of the brain and the amygdala. In the context of passion, the brain’s judgment and fear centers are on leave. Love also shuts down the centers necessary to mentalize or sustain a theory of mind. Lovers stop differentiating you from me.

Faith is also being studied. Earlier this year the Annals of Neurology published an article by Sam Harris and colleagues exploring what happens in the brain when people are in the act of either believing or disbelieving. In an accompanying editorial, Oliver Sachs and Joy Hirsch underscored the significance of what the researchers found. Belief and disbelief activated different regions of the brain. But in the brain, all belief reactions looked the same, whether the stimulus was relatively neutral: an equation like (2+6)+8=16, or emotionally charged: “A Personal God exists, just as the Bible describes.”

By putting a big religious idea next to a small math equation, some readers might think the researchers intend to glibly dismiss it. But a discovery about brain function does not imply a value judgment. And understanding the reality of the natural world—how the brain works—shouldn’t muddle the big questions about human experience. It should help us answer them.

October 3, 2008

Does Religion Make You Nice?

HOT OFF THE PRESS! (3 Oct 2008)

The very latest issue of the Science journal has published a review of religious prosociality.

This is an issue that has an indirect connection with my recent Masters thesis. What a pity this wasn't published a little earlier, as I could have incorporated some of this data into my thesis.

But never mind, I'll read this review and criticise it here soon.

In plain English (as per the abstract): This review examines the evidence for religious prosociality, in other words, the extent to which religion goes in ensuring you're a "good guy". Do you help people and do favours for them because of your natural niceness, or because your religion tells you to? While surveys find a correlation between religiosity and helpful behaviour, experiments have found that this correlation occurs mainly in context where the reputation of the 'helper' is enhanced. In other words, religiously-motivated helpers want to do good and be seen doing good. Other experiments find that religious thoughts reduce the inclination to cheat and increase helpful behaviour towards random strangers.

I don't know what the rest of it means (re devotion and trust, morally concerned deities, etc) as I'll have to read it to find out. But this is a taste!

October 2, 2008

Let's Celebrate The Real Big Questions

Although it isn't directly relevant to neuroscience or neuropsychology, this excellent essay from Lawrence Krauss in the September (2008) edition of New Scientist discusses premises that I often encounter in my discussions with people:
LAST year I agreed to write a short essay for an advertisement featuring the question: "Does the universe have a purpose?" It was to appear in major media outlets, including The New York Times, The Economist and New Scientist. I was asked to express my views in my own words, so I wasn't worried that they would be distorted to support an ulterior agenda. I considered the ad a useful outlet for communicating how I believe science can inform this question.

I was naive. The ad, which was sponsored by the John Templeton Foundation - an organisation that aims to find links between science and religion - was the first instalment in a Big Ideas series, and has been followed up by essays on: "Does science make belief in God obsolete?" Next week the otherwise well-grounded Skeptics Society is to run a related conference, also sponsored by Templeton, called Origins. According to their promotional material, "the Big Questions... involve Origins", such as the origins of the universe, the laws of nature, time's arrow, life and consciousness. "Science is making significant headway into providing natural explanations for these ultimate questions, which leaves us with the biggest question of all: does science make belief in God obsolete?"

Unfortunately, despite the money being channelled into such meetings and ads, this is neither a very big question nor a very big idea. The issue may be of importance to some theologians and philosophers, but it is essentially irrelevant to scientists. In the academic departments where these origins are being investigated, the question is almost never raised.

Scientists may, if asked, express views on issues relating to purpose and religion, especially to counter ill-conceived notions that might mislead the public, but in our work we focus on scientific questions that can be addressed by the tools we have to explore the universe. Whether any form of modern religion is made obsolete by our progress is a tangential and almost trivial point. If new knowledge about the universe cannot be worked into these philosophies, they will become obsolete. Otherwise, they persist.

While the participants have changed, the so-called debate over the relation between science and religion has hardly progressed in 400 years. Today's arguments about intelligent design, for example, are little different from those of Thomas Aquinas and William Paley, though the realm in which the debate is taking place has been shifted from human scales to scales that are many, many times smaller or larger. Focusing on such stale and fruitless questions prevents the public from appreciating the truly interesting intellectual frontiers in science.

I recently moved to Arizona to lead a new programme on Origins at Arizona State University. Its purpose is to explore and celebrate emerging knowledge on origins: from that of the universe to humanity, consciousness to culture. We will be sponsoring, among other things, a big public event in Phoenix in April 2009, where speakers including Stephen Hawking, Richard Dawkins, Craig Venter, Brian Greene and Steven Pinker will focus on the real questions driving intellectual progress across science. Is there a multiverse? Are the laws of nature unique? What caused the big bang? How did life arise on Earth? How abundant and diverse is life in the universe? How did humans evolve consciousness? Can machines think? Can we genetically re-engineer humans?

These are the questions that reflect the remarkable upheavals and challenges that our understanding of nature has faced over the past century. Our efforts to answer them will form the basis of knowledge and action in the next.