Larry Moran passes on the rules of the game: go to the Wellcome Library’s new image bank and find your favorite scientific image. Here’s my pick: the first good picture of the brain, drawn by Christopher Wren in 1664 for Thomas Willis, the first neurologist. (More on Willis and Wren here.)

[Credit: Wellcome Institute, Creative Commons License.]

You may have read not long ago about birds that can plan for the future. The occasion was a paper that came out in the journal Nature detailing some experiments on scrub jays. I found the paper fascinating, not just for the results themselves, but for the many other studies on mental time travel that are going on these days dealing with other animals–rats, pigeons, monkeys, and us. Instead of simply reporting on one experiment, I took some extra time and took a survey of the past and future of mental time travel. It appears in tomorrow’s New York Times.

For those who crave more, here are some key papers behind the story:

**Scrub jays and foresight

**Rats and episodic memories

**Monkeys and foresight

**Episodic memory in humans

**The evolution of foresight in humans (pdf, in review)

**Brain scans linking past and future (pdf)

All I want for Christmas is a lying frog and a bubble-sniffing mole.

For those who want to head for the original papers, check out:

1. “Why Animals Lie: How Dishonesty and Belief Can Coexist in a Signaling System” (free full text)

2. “Underwater ‘sniffing’ by semi-aquatic mammals”

Happy Holidays!

UPDATE 12/26: Forgot to mention yesterday that I also talk about the dishonesty article on this week’s edition of the Times Science podcast.

Congratulations to the new crop of Macarthur genius grant winners, including Ken Catania, a neuroscientist at Vanderbilt University whose muse is the star-nosed mole. It turns out that a single strange animal can reveal a lot about how nervous systems develop and evolve. For more on Catania’s work, see my blog post from last year and my article on some of Catania’s recent work for the New York Times.

Before 1833 there were no scientists.

It was in that year that William Whewell, a British philosopher, geologist, and all-around bright bulb, coined the word scientist. His mentor, the poet Samuel Coleridge, thought the English language needed a term for someone who studied the natural world but who did not inhabit the lofty heights of philosophy (like Coleridge).

There are plenty of people who lived before 1833 that most of us would call scientists–Isaac Newton, Antoine Lavoisier, Edmund Halley, Carol Linnaeus to name just a few. But the word would have been meaningless to them. The closest term they might use was “natural philosopher.” Their work and ideas were still deeply rooted in medieval ways of thinking about the world, and about the work they did.

Science did not emerge suddenly in a sudden onslaught of Modern Reason crushing Old Ignorance. Its rise was much slower and much more interesting. One of the most important parts of science as we know it is a way for people to share their observations and experiments. Today peer-reviewed journals are at the core of the scientific process. But until the seventeenth century, nothing like them existed. Natural philosophers generally were more interested in what the ancient Greeks and Romans had to say about medicine, physics, and biology, than what they might observe for themselves. In 1665, a group of natural philosophers in England got together and decided to publish what is arguably the first scientific journal: the Philosophical Transactions of the Royal Society of London.

It’s still going strong today, putting out a lot of important papers. And for the next couple months, the Royal Society is making the entire archive–all the way back to 1665–available for free.

In a press release, the Royal Society pointed to some particularly neat papers, such as Ben Franklin’s 1752 description of flying a kite in a thunderstorm. But I immediately looked up a much older paper about lightning from 1666, entitled “A relation of an accident by thunder and lightning, at Oxford.”

I first came across this paper a couple years ago while working on my book Soul Made Flesh. In the book, I describe how scientists natural philosophers discovered how the brain works in the 1600s. I focus mainly on Thomas Willis, widely considered the first neurologist. Willis did astonishing work, recognizing some of the fundamental features of the brain–that the flesh of the brain itself was the seat of thought, for example, rather than the spaces around it, known as ventricles. Willis published the first accurate pictures of the brain, in the first book about the brain. He argued that melancholy, epilepsy, and nightmares were all chemical disturbances in the brain. He even coined the word neurology.

For all that, however, Willis was still floundering in the dark. He had no idea of how the brain communicated with the rest of the body. He laid out an elaborate theory about how particles (“spirits”) moved around in the brain and then traveled down the nerves. But he had no actual evidence for this idea. And he knew nothing about electricity.

The communication recounts how Willis and his colleagues dissected a man killed by lightning. The bolt had thrown its victim, an Oxford scholar, out of the boat he had been rowing. When the scholar’s body was brought back to town, Thomas Willis came to see it along with his assistant Richard Lower and the mathematician John Wallis, who later wrote the . They picked up the man’s hat and put their fists through the hole the lightning had torn. His doublet had been ripped open and his buttons knocked off. Willis and his friends found spots and streaks across the torso where the skin seemed to be seared and hard, “like Leather burnt with the fire,” Wallis later wrote to the Royal Society.

The following night Willis and company returned, along with a crowd of onlookers, to cut the man open. “The whole Body was, by night, very much swell’d,” Wallis wrote. The stench that rose from the body was unbearable, but they soldiered on because such an opportunity might not come again in their lives. “There appear’d no sign of contusion,” Wallis wrote, “the brain full and in good order; the nerves whole and sound, the vessels of the brain pretty full of blood.” They opened the man’s chest and found that the burns did not reach below the skin. “The Lungs and Heart appear’d all well, and well-colour’d without any disorder,” Wallis wrote. The heavens had struck the man dead, and yet the natural philosophers could find nothing changed inside the body.

It would take Benjamin Franklin and other eighteenth century scientists to begin working out the nature of electricity, and to recognize its role in the nervous system. But I still like to picture Willis puzzling over a cadaver, not realizing that the man had been killed by the same thing that made thought possible.

Here are some other landmark papers you can find in the archives…get them while you can.

The Complementary Structure of Deoxyribonucleic Acid
F.H.C Crick and J.D Watson – 1954

On the Hoyle-Narlikar Theory of Gravitation
S. W. Hawking – 1965

An Account of an Experiment Made by Mr. Hook, of Preserving Animals Alive by Blowing through Their Lungs with Bellows
Robert Hooke – 1667

An Account of a Very Odd Monstrous Calf
Robert Boyle – 1665

Observables upon a Monstrous Head
Robert Boyle – 1666

Account of a very remarkable young musician (Mozart)
Daines Barrington – 1770

Alexander Fleming (Paper describing early stages of penicillin discoveries) – 1922

Arthur Eddington’s solar eclipse observations, confirming Einstein’s general theory of relativity (Phil Trans 1919)

John Noble Wilford has a long, interesting article in today’s New York Times on the rehabilitation of the alchemist. Once the icon of the bad old days before the scientific revolution, alchemy has been emerging in recent years as more of a proto-science. Indeed, a fair number of the heroes of the scientific revolution were dyed-in-the-wool alchemists. Robert Boyle, one of the founders of chemistry, wanted to reform alchemy, not destroy it. He chased after the philsopher’s stone for his whole life. Many of his papers were destroyed in the eighteenth century because they were loaded with discussions of alchemy–which by then had acquired its bad reputation. Boyle’s legacy had to be protected.

Wilford reported from a recent meeting of historians of chemistry in Philadelphia. From his report (as well as this one from the New York Sun and this one from Chemical and Engineering News), it seems as if the meeting neglected one of the most interesting sides of alchemy: its role in the history of bio-chemistry. Alchemists believed that the life was the greatest transmutation of all, and they believed that the philsopher’s stone would serve as the ultimate medicine. While a lot of alchemists dealt in Kevin-Trudeau-style hogwash, some did important work.

Jan Baptist van Helmont, a sixteenth-century Belgian alchemist, carried out a classic experiment on biological growth. He put a five pound willow sapling in a tube of 200 pounds of earth. For five years he gave the tree nothing but water, and then weighed both tree and earth. The tree had grown to 169 pounds, while the earth had lost a few ounces. “Hence one hundred and sixty-four pounds of wood, bark, and roots have come up from water alone,” he announced. Van Helmont believed that the willow was nothing more than transmuted water, given form by the willow’s inner soul.

I first came to appreciate the importance of alchemy in the rise of biochemistry while working on my book Soul Made Flesh, on the history of neurology. Thomas Willis, the first neurologist, started out as an alchemist, deeply influenced by Van Helmont. He came into contact with Robert Boyle through their shared interest in alchemy. And his first important work was a book that used alchemy to reinterpret physiology. Instead of the four humours, Willis saw body being made up of corpuscles of different sorts, borrowing concepts of Van Helmont and other alchemists. These corpuscles interacted with one another to produce changes, just as ferments made bread rise and grape juice turn to wine.

Willis later did groundbreaking work on the anatomy and function of the brain, which until his time had generally been considered a pretty useless organ. Willis envisioned the brain as an alembic, the distilling container of alchemy, in which some of the corpuscles of the blood were distilled into the animal spirits, which then flowed through the nerves. While some of Willis’s language and concepts are now hopelessly old-fashioned, he set the study of the brain–and thus the soul–on a new foundation.

The intersection of alchemy and biology is just further evidence that science does not advance by simply wiping the slate clean and starting completely from scratch. Some of the most dramatic revolutions were born within systems of thought that today seem hopelessly backwards. I wonder how twenty-ninth cenutry historians will look back at our own revolutions today. Who will be cast aside as the new alchemists?

It’s always great to hear senior scientists talk about the bad old days, when one computer could fill an entire room and no one could say what genes were made of. Eric Kandel of Columbia has been studying memory since the 1950s, and won the Nobel Prize in 2000 for his work. These days he’s observing genes switching on and off at the junctions between neurons. But when he started out, he had to content himself with sticking electrodes into crayfish (chosen for their fat neurons). To observe their neurons, scientists would hook up the electrodes to amplifiers and loudspeakers, and the crackle of nerves would fill the room. With hindsight, we can cluck at the primitiveness of it all. But for Kandel, it was a new world. He had wanted to find Freud’s ego and the rest in the brain, and quickly discovered that it was a futile task. But being able to hear a crayfish’s neurons was, to him, the ultimate psychoanalysis.

For more on Kandel, you can read my new profile. The article is in the New York Academy of Science’s webzine (as well as the hard-copy version). They’ve also got a link to a recent lecture Kandel gave at NYAS that was the spur for the article.

I have a fondness for collecting brain lore–memes about the wonders of the human brain that race around the world for decades. The classic of brain lore is the “ten-percent myth.” As I wrote here, people often claim we only use ten percent of our brain, implying that we’d be supergeniuses if we could just switch on the rest. But that’s just based on a misinterpretation of some studies in the 1930s. Actually, the energy consumed by the cortex is only enough to power one percent of its neurons at any time.

In a press release descibing the work of Stanford bioengineer Kwabena Boahen, I stumbled on another meme:

According to Boahen, the brain is capable of performing 10 quadrillion (that’s 10 to the 16th) “calculations,” or synaptic events, per second using only 10 watts of power. At this rate, he says, a computer as powerful as the human brain would require 1 gigawatt of power.

I searched for the origin of this meme, and discovered Paul Valery, an early 20th century poet and essayist. He declared:

The ultimate “computer,” our own brain, uses only ten watts of power — one-tenth the energy consumed by a hundred-watt bulb.

It’s a claim that falls in that gray zone, the intersection of cool and crazy. So to see if it was actually true, I asked Bill Leonard, an expert on the evolution of human brains at Northwestern University. He responded thusly:

This is really interesting. The 10 watt estimate looks pretty close to being correct — perhaps a bit on a the low side, but certainly in the ballpark.

In terms of calories, here is how the 10 watts translate:

10 watts = 10 joules/sec = 207 kcal/day for the brain

At 200-210 kcals, this is enough energy to support a brain of about 1000 grams, at the low end of the modern human range.

For an average size human brain — 1300 -1400 grams — the costs would be a bit higher — between 250-300 kcal/day. However, this would only up the “wattage” to about 15.

So there you go. One urban myth survives the cold scrutiny of reason! Pass it on in the full confidence that it’s true (not to mention amazing).

Scientists studying people in minimally conscious states have published the results of brain scans showing that these people can retain a surprising amount of brain activity. The New York Times and MSNBC, among others, have written up accounts.

I profiled these scientists for a 2003 article in the New York Times Magazine, when they were at an earlier stage in their research. Things certainly have changed since then. When my article came out, hardly anyone had heard of Terri Schiavo, the Florida woman in a permanent vegetative state who is at the center of a battle between her parents, who want to keep her feeding tube in, and her husband, who wants it taken out. Since then, her case has made national headlines, and a law has been passed in her name. I for one will be keeping close attention to how this new paper is received (and used) in the debate over Terri Schiavo, because I had the displeasure of watching my article get pulled into the debate and distorted for political ends.

The key point to bear in mind about this new research is that there’s a difference between people in a permanent vegetative state and people in a minimally conscious state. Neurologists have developed bedside tests to determine which state a given patient is in. People in minimally conscious states show fleeting, but authentic, awareness of their surroundings, for example. People in vegetative states do not. Neurologists cannot make this diagnosis from the reports of family members, because it is easy to see awareness in a loved one when there is, in fact, none. That doesn’t mean that family members are necessarily wrong if they say a loved one is aware. It’s just that a doctor needs to test a patient objectively, using methods that don’t rely on his or her own interpretation.

Some people have argued that this test is circular: people are simply defined minimally conscious if they pass a test for minimal consciousness. But the designers of the test have shown that it does have predictive power. For one thing, people who rise to a minimally conscious state have a small but real chance of recovering consciousness (although they may never return to their former selves). People who stay in a permanent vegetative state for many years, by contrast, almost never recover.

The brain scan findings now being reported also strengthen the notion of a minimally conscious state. The researchers scanned the brains of patients diagnosed as minimally conscious, playing the voice of loved ones through headphones, scratching their skin, and doing other tests to check for the function of their brain. They found that the patients responded in important ways. Some patients responded to the recordings with strong activity in regions of the brain involved in language and memory, for example. But in the absence of stimuli, the brains of the patients used less energy than a person would under anesthesia.

On the other hand, earlier scans of people diagnosed as being in a permanently vegetative state showed at most only isolated islands of activity in the cortex, where higher brain functions take place. So the difference detected by bedside tests is mirrored by a difference detected in the brain scanner.

It’s crucial neither to overplay or underplay the importance of this work. People who are coping with the staggering burden of a loved one in a truly permanent vegetative state should not see this as evidence that their loved one is conscious and simply "locked in" to an unresponsive body. Nor should pundits raise false hopes by claiming that this is the case.

But it is also true that people with impaired consciousness are not getting the attention they deserve, starting with a good diagnosis. Thirty percent of people in a permanent vegetative state may actually be minimally conscious. It would be fantastic if some day doctors could make a precise diagnosis of brain-damaged patients simply by running them through some tests in a scanner. For now, though, only a handful of people with impaired consciousness in the entire world have been scanned at all. Eventually, it might be possible to use the knowledge gained from these tests to start finding ways to help people recover more of their consciousness, perhaps through brain stimulation. Today there’s nothing a doctor can do but wait and watch.

Unfortunately, people with impaired consciousness are more likely to be simply warehoused, getting hardly any attention from a neurologist. Are we, as a society, ready to give these voiceless people the care they deserve?

Soul Made Flesh made Amazon.com’s Editor’s Pick list of the ten best science books of 2004. It’s an honor, although it seems a little premature to call 2004 over!

I am sure that in 50 years, we are going to know a lot more about how the mind works. The fusion of psychology and genetics will tell us about how our personality is influenced by our genes, and they’ll also show exactly how the environment plays a hand as well. The preliminary evidence is just too impressive to seriously doubt it. Likewise, I am sure that we will have a deeper understanding how our minds have evolved, pinpointing the changes in DNA over the past six million years have given us brains that work very differently than apes. Again, the first results can’t help but inspire a lot of hope.

Given where I stand on all this, I would have thought that I’d enjoy Dean Hamer’s new book, The God Gene: How Faith is Hard-Wired In Our DNA. The time is ripe, judging from the string of books that have been published in the past few years on the link between religion and biology. I thought that Hamer, a geneticist, might be able to throw some interesting information into the mix, thanks to his expertise in behavioral genetics. The book turned out to be elegant and provocative, and, as I write in my review in the new issue of Scientific American, disappointingly thin on the evidence. From a single study that Hamer hasn’t even published yet, he weaves an incredibly elaborate scenario in which faith is an adaptive trait. I wouldn’t be surprised if it is the product in some way of natural selection, but now is hardly the time to be writing a book claiming to have figured out its origins–not to mention making appearances on talk shows and the like. Too many links between behavior and genes have already crashed and burned (including some Hamer himself has made).

Update, 9/27: Scientific American has posted the review on their site

The soft spot on a baby’s head may be able to tell us when our ancestors first began to speak.

We have tremendously huge brains–six times bigger than the typical brain of a mammal our size. Obviously, that big size brings some fabulous benefits–consciousness, reasoning, and so on. But it has forced a drastic reorganization of the way we grow up. Most primates are born with a brain fairly close to its adult size. A macaque brain, for example, is 70% of adult size at birth. Apes, on the other hand, have bigger brains, and more of their brain growth takes place after birth. A chimpanzee is born with a brain 40% of its adult size, and by the end of its first year it has reached 80% of adult size. Humans have taken this trend to an almost absurd extreme. We are born with brains that are only 25% the size of an adult brain. By the end of our first year, our brains have reached only 50%. Even at age 10, our brains are not done growing, having reached 95% of adult size. For over a decade, in other words, we have newborn brains.

It’s likely that this growth pattern evolved as a solution to a paradox of pregnancy. Brains demand huge amounts of energy. If mothers were to give birth to babies with adult-sized brains, they would have to supply their unborn children with a lot more calories in utero. Moreover, childbirth is already a tight fit that can put a mother’s life in jeopardy. Expand the baby’s head more, and you raise the risks even higher.

Extending the growth of the brain obviously gave us big brains, but it may have endowed us with another gift. All that growth now happened not in the dark confines of the womb, but over the course of years of childhood. Instead of floating in an aminotic sac, children run around, fall off chairs, bang on pots, and see how loud they can scream. (At least mine do.) In other words, they are experiencing what it’s like to control their body in the outside world. And because their brains are still developing, they can easily make new connections to learn from these experiences. Some researchers even argue that only after the brains of our ancestors became plastic was it possible for them to begin to use language. After all, language is one of the most important things that children learn, and they do a far better job of learning it than adults do. If scientists could somehow find a marker in hominid fossils that shows how their brains grew, it might be possible to put a date on the origin of language.

That’s where the soft spot comes in.

The oldest hominids that look anything like humans first emerged in Africa about 2 million years ago. They were about as tall as us, with long legs and arms, narrow rib cages, flat faces, and small teeth. The earliest of these human-like hominids are known as Homo ergaster, but they rapidly gave rise to a long-lived species called Homo erectus. H. erectus probably originated in Africa, but then burst out of the home continent and spread across Asia to Indonesia and China. The Homo erectus people who stayed behind in Africa are probably our own ancestors. The Asian H. erectus thrived until less than 100,000 years ago. They could make simple stone axes and choppers, and had brains about two-thirds the size of ours.

Paleoanthropologists have found only a single braincase of a baby Homo erectus. It was discovered in Indonesia in 1936, and has since been dated to 1.8 million years old–close to the origin of the species. While scientists have had a long time to study it, they haven’t made a lot of progress. One problem is that the fossil lacks jaws or teeth, which can offer clues to the age of a hominid skull. The other problem is that the interior of the braincase was filled with rock, making it hard to chart its anatomy.

In the new issue of Nature, a team of researchers rectified this problem with the help of a CT scanner. They were able to calculate the volume of the child’s brain, and then they were able to map the bones of the skull more accurately. As babies grow, the soft spot on their skull closes up and other bones are also rearranged in a predictable sequence. Chimpanzees, our closest living relatives, also close up their skulls in the same pattern, with some small differences in timing. The H. erectus baby, its skull shows, was somewhere between six and eighteen months old. Despite its tender age, the Homo erectus baby had a big brain–84% the size of adult Homo erectus brains as measured in fossil skulls.

A single battered braincase still leaves plenty of room for uncertainty, but it’s still a pretty astonishing result. At a year old, this Homo erectus baby was almost finished growing its brain. It spent very little time developing its brain outside the womb, suggesting that it didn’t have enough opportunity to develop the sophisticated sort of thinking that modern human children do. If that’s true, then it’s unlikely it could ever learn to speak. If these researchers are right, then future CT scans of younger hominid skulls should be able to track the rise of our long childhood.