Yet versatility is not always a virtue, and more of it is not always better. When the chimpanzees of Uganda arrive at a grove of fruit trees, they often discover that the efficient local..

The most interesting of our 1997 travels was Bellagio, Italy. It's hard to explain this without lapsing into superlatives over and over, so let me try bare facts first. The Rockefeller Foundation was, in the 1950s, given a 50-acre estate known as the Villa Serbelloni. It was also given enough endowment to maintain the place and run it as a retreat ("The Bellagio Study and Conference Center") for..

I have two tales to tell. Well, maybe three. Presently I will get to the good news concerning what knowledge of the brain will do to education and training by 2025, making adults far more mentally capable than most of us are now, with all its implications for warfare and other less lethal forms of competition.

That’s Bill Calvin, whose brain is worthy of study in its own right. Technically, he’s a theoretical neurophysiologist and affiliate professor of psychiatry and behavioral sciences at the University of Washington. But he’s also known as a scientist with a wide-ranging intellect and a prolific (and accessible) writer who constantly offers remarkable insights about the world around him. As I sat down to interview Calvin in his book-lined Seattle home last Fall, I recalled the comments of someone who had come (...) to GBN to hear Calvin speak. He said that he didn’t know—or care—what Calvin was going to talk about because everything that Bill Calvin said was not only interesting, but worth learning about. After more than three hours of conversation with Calvin, I couldn’t agree more. (shrink)

Computer simulations may allow us to understand the earth’s fickle climate and how it is affected by detours of the great ocean currents. These detours cause abrupt coolings -- the average global temperature can drop dramatically in just a few years, with droughts that set up El-Niño-like forest fires even in the tropics. While volcanic eruptions and Antarctic ice shelf collapses can also abruptly cool things, what we’re talking about here is a flip-flop: a few centuries later, there’s an equally (...) abrupt rewarming. This cycle has repeated every few thousand years (though it has been 12,000 years since the most recent one). (shrink)

When surveying the spectrum from pop psych to neurology in works addressed to general readers, one is struck by how few major figures there have been - certainly when cognitive neuro is compared to a far smaller field (1), evolutionary biology, where real literary talents like Loren Eiseley once flourished, where "media dons" like Richard Dawkins regularly clarify our thinking, where there are magnificent series like those of Stephen Jay Gould (fifteen major essays a year, plus scholarly books and research (...) papers, spanning three decades) which have influenced millions to read more. Many writers in the cognitive spectrum have occasionally written an influential book or two, but few could fill the largest available campus auditorium on name recognition alone, even without announcing a topic for the lecture. (shrink)

German translation Der Strom der bergauf fließt: Ein Reise durch die Evolution (Carl Hanser Verlag, 1994), DM58-. [click here to see German cover].

The self, Joseph LeDoux tells us, is “the totality of the living organism”. Most disciplines in the natural sciences focus on only one or two levels of organization. Indeed, Dmitri Mendeleev figured out the periodic table of the elements without knowing any of the underlying quantum mechanics or stereochemistry. There are, however, at least a dozen levels of organization within the neurosciences — and, if we use a metaphor, we temporarily create yet another. This leads to considerable confusion and arguments (...) at cross purposes over whether learning is an alteration at the level of gene expression, ion channels, synapses, neurons or circuits. Each neuron has thousands of synapses, which produce currents that summate to form an impulse train. But only rarely is the activity of a single neuron sufficient to cause a perception or trigger an action. Neurons usually act as members of ‘committees’ — what Donald Hebb in 1949 called cellassemblies. Just as in academia, one individual may function in different committees on different occasions. A concept, including any explicit memory that we can talk about, is probably formed by such a committee. Implicit memories are less differentiated — they are part of the ‘feltwork’, together with motivations and emotions, that biases the choice of one’s next act. In this well-written 400-page appreciation of behavioural neuroscience, LeDoux argues that synapses are the seat of self. He says, in effect, that you are your memories; that it is the uniqueness of an array of synaptic strengths that distinguishes one twin from another. Fair enough, but why not instead focus on one’s unique array of ion channels? Or neurons, because a neuron is the closest thing we have to a computational unit? Or one’s unique arrangement of those overlapping, redundant hebbian committees? None of these make for a catchy book title, but relating other things to the synapses proves to be a good way of covering a lot of fascinating material at the overlying levels, including a few updates to LeDoux’s earlier book The Emotional Brain. (shrink)

In particular, one of Gould's important contributions as a paleontologist was to convince us that there are long periods in evolution where species don't change very much, that Darwinian gradualism doesn't guarantee a steady course of improvements. And that there are periods -- not at all inconsistent with Darwinian gradualism -- when things progress considerably faster. I tuned right into what Steve was saying since both of my main interests in evolution, the evolution of the big brain in only several (...) million years, and the use of the Darwinian process in the brain to improve the quality of the next sentence you speak in a matter of seconds, involve the search for speedy ways of evolving things. (shrink)

Placez la photographie du cerveau d’Einstein au milieu d’une centaine d’autres clichés du même type : il ne fait aucun doute que n’importe quel étudiant en neurosciences le repérerait immédiatement. “ C’est aussi étrange que d’avoir deux pieds gauches , dirait-il. Comment cet individu pouvait-il danser avec deux cerveaux droits ? S’agissait-il d’un attardé mental ou d’un génie ? ” Les règles de l’origami prénatal nous sont encore largement inconnues, mais chaque étudiant apprend vite à distinguer les replis les plus (...) profonds du cerveau, tels le sillon central (tout ce qui est situé en avant de ce sillon est appelé le “ lobe frontal ”) et la scissure de Sylvius (tout ce qui est situé en dessous de cette scissure est appelé le “ lobe temporal ”). Habituellement, les deux hémisphères n’ont pas la même apparence : dans un cerveau droit typique, la scissure de Sylvius prend un tournant abrupt, un peu en arrière du sillon central, tandis que, dans le cerveau gauche, sa courbure est beaucoup moins prononcée (voir l’article d’Olivier Robain). Il sauterait donc aux yeux de notre étudiant que ces pliures dans les cerveaux droit et gauche d’Einstein sont curieusement similaires. Autre bizarrerie, les coudes des scissures de Sylvius sont situés plus en avant qu’à l’ordinaire : chez Einstein, toutes les deux aboutissent dans le sillon central. (shrink)

A: That's easy: abrupt climate change, the sort of thing where most of the earth returns to ice-age temperatures in just a decade or two, accompanied by a major worldwide drought. Then, centuries later, it flips back just as quickly. This has happened hundreds of times in the past.

Neurons run on electricity 1, producing many impulses each second when they are working hard. These brief (1/1000 second, as rapid as a fast camera shutter), 0.1 volt impulses (though a hundred times smaller if recorded from outside the cell) can be amplified and heard via a loudspeaker. Neurophysiologists routinely listen to neurons via loudspeakers in their laboratories, much as anesthesiologists listen to a patient's heartbeat in the operating room.

I will actually talk mostly about evolutionary processes in the brain as we think about what to say next; I'll be happy to answer questions later, however, about how this system we call consciousness itself evolved on the usual evolutionary time scale of the ice ages.

Antonio R. Damasio , The Feeling of What Happens: Body and Emotion in the Making of Consciousness . This is clearly a must-read book for anyone wanting a neurologist's perspective on one of the greatest of the unsolved mysteries, human consciousness and the ways in which it exceeds that of the other apes. By the author of Descartes' Error.

Psychology's fascination with memory and its imperfections dates back further than we can remember. The first careful experimental studies of memory were published in 1885 by German psychologist Hermann Ebbinghaus, and tens of thousands of memory studies have been conducted since. What has been learned, and what might the future of memory be?

Homo erectus made symmetrical tools. The handaxe is a flattened tear-drop shape, but often with edges sharpened all around. Before we assign their obsession with symmetry to an esthetic judgment, we must consider whether it is possible that the symmetry is simply very pragmatic for one particular use of the many suggested.