Blogs / The Loom

There’s a neat paper in Nature today suggesting that astrocytes, part of the brain’s hidden majority, plays a big role in the formation of memories. The Scientist has details. For background, check out my September Discover column.

Here’s a talk by Ian Couzin, a scientist who does fascinating studies on crowds and their wisdom. I wrote about Ian a couple years in the New York Times. It’s funny now to actually see him in the virtual flesh. And to hear him talk about how much he loves the Pixies.

A healthy brain, with white matter tracts visualized with diffusion tensor imaging. Source.

How is your brain like a telegraph? Check out my latest column in Discover for the answer.

Math is the subject of my new Discover column on the brain. How do we do it, and when did we (or our primate ancestors) start doing it? The answer, or at least some intriguing new research, is here.

This video shows what happens inside a (straight) man’s brain in the first fraction of a second that he looks at a picture of a sexually desirable woman. There’s a lot going on in there–not just the flare-up of some primordial reptile brain. In my latest column for Discover, I take a look at the history of neuroscience’s exploration of desire, from the earliest studies on tumors that triggered orgasms to the latest in neuroimaging. Check it out.

[Video courtesy of Stephanie Ortigue of Syracuse University]

Your Brain on Sex from DISCOVERmagazine.com on Vimeo.

From time to time, I’ve asked around for a good estimate of how many neurons are in the human brain. Ten billion–100 billion–something like that, is the typical answer I get. But there are actually a trillion other cells in the brain. They’re known as glia, which is Latin for glue–which gives you an idea of how little scientists have thought of them. But without glia, our brains would be useless. Scientists don’t yet really understand all the things that glia do for us, but it looks as if they do a lot–perhaps even processing information in their own mysterious way.

In my brain column in the September issue of Discover, I consider the long-neglected neurological elephant in the corner. Check it out.

[Image from Neurophysiology for the Audiologist]

The National Institutes of Health funds research on the biology of morality in the human brain, as well as the evolution of  human morality by comparing humans to other primates. Francis Collins, who has been nominated to head NIH, has repeatedly criticized this sort of research–and has used its failure as evidence for the existence of God. In 2008, for example, he said, “I think human altruism can be seen as one of strongest signposts to the existence of a personal God. I can see no fully satisfactory explanation for it coming from biology.”

I’d be curious to know if Collins thinks NIH shouldn’t have funded this research in the past, and if he would cut it in the future. If I were a reporter who went to DC press conferences rather than one that sits at home in his slippers, that’s the question I’d ask–not as a gotcha question, but as a matter on which I cannot figure out an answer based on what he’s said in the past.

Update: Frans de Waal, who does the NIH-funded research on primates I linked to above (and writes lots of interesting trade books on said topic), posted a response I’m pulling up here into the post itself:

Yes, Collins has in the past taken human altruism as proof that God exists, seeing it as a miraculous trait that evolution couldn’t possibly have produced. I disagree, having argued that the building blocks of morality can be found in other animals. I am closer to Darwin than CS Lewis on this. But in response to your blog I must say that I am not sure that Collins will have the power to prevent specific research (such as neuroscience on morality). Furthermore I doubt that he wouldn’t want to know the answers. He is a scientist, after all, and I bet he is open-minded enough to be curious about the outcome of such research even if it doesn’t fully agree with his previous position. Or, am I just being an optimist here?

Thanks for your thoughts, Frans. Of one thing I am sure: the labyrinth of NIH funding is terra incognita for me.

Update #2: Ken Miller, a biologist well known for his books on the relationship between science and religions, has also left a comment:

The worry that Francis Collins would use his position at the NIH to “proselytize” or would not back researchers whom “the religious right dislikes” isn’t grounded in the reality of the man’s life and career.  I’m no more worried about Collins using NIH to advance his religious views than I was about Harold Varmus using the same position to advance non-religious views.  Varmus was a great Director because he was a first-rate scientist who understood how to administer research, and Collins matches him on both counts.

Yes, Collins has written that he doesn’t think that biological evolution can explain the human moral sense.  I disagree with him on that point, even as a fellow Christian.  But Collins’ whole career has been marked by openness, fair-mindedness, and above all, a driving intellectual curiosity.  The over-reaction of those sounding the warning sirens about him is without foundation in fact.  It’s also emotional to the point of irrationality.  PZ Myers has called him “a clown,” and written that “The man is a flaming idjit.”  This comes from a guy who opposes Collins in the name of scientific reason? 

In my June brain column for Discover, I wrote about the bizarre idea that there are single neurons in your head that can respond to individual people. The so-called “grandmother cell” started out 40 years ago as a thought experiment riffing on Philip Roth’s novel Portnoy’s Complaint. By the 1970s, most neuroscientists considered it more of a joke than a valid concept, but in the years since it hasn’t quite gone away.

In my column, I described the work of the work of Rodrigo Quian Quiroga of the University of Leicester:

For the past eight years, he and his colleagues have been studying epilepsy patients who have had electrodes implanted in a region of their brains called the medial temporal lobe, as part of a study to identify the source of their seizures. Quian Quiroga showed the subjects 100 pictures. The pictures included photos and drawings of celebrities as well as landmarks and various familiar objects. The patients had to press one button if a picture was of a human face and another if it was not.

In their first such study, Quian Quiroga and his team were able to observe the individual activity of 993 neurons. They found that 132 of them responded to at least one picture. And of those responding neurons, 51 fired in response to only a single person or thing. One neuron responded only to Halle Berry, for example.

Amazingly, the “Halle Berry” neuron responded to any picture of her, including one in which she was dressed as the masked Catwoman. Even the name Halle Berry triggered that neuron, which was silent at the sight of other actresses or their names.

Quian Quiroga does not, however, believe these neurons are grandmother cells, at least as they were initially conceived. He suspect that a very sparse network of neurons–perhaps hundreds out of the billions in our heads–can develop this kind of response to an individual. Quian Quiroga just happen to stick his electrodes near single neurons that belonged to these networks.

Which brings us to Quian Quiroga’s latest paper, published in Current Biology. He analyzed the signals from 750 electrodes implanted in seven patients as they looked at pictures of some celebrities like Oprah Winfrey. Quian Quiroga found neurons that responded strongly to the sight of these individuals–and they also responded strongly to their written names and even the sounds of their names.

Quiroga and his colleagues also ran the same test using themselves rather than the celebrities to probe for neurons. They discovered neurons that responded strongly only to individual researchers, too–and once more, the same neurons responded to the sight and sound of their name. Bear in mind–the patients had only met the scientists a day or two earlier. So these neurons had developed their grandmother-ish response in a very short time.

These results offer some clues to how these sparse networks are arranged. Some of the neurons probably get signals from other regions of the brain that recognize faces. Others tap into auditory networks, and others language centers. Yet, remarkably, the information from these far-flung parts of the brain get funneled into tiny sets of neurons that can then encode concepts of people.

They may not be the Grandmother Cells of legend, but in their own way, they’re very cool.

Reference:  Quian Quiroga et al., Explicit Encoding of Multimodal Percepts by Single Neurons in the Human
Brain, Current Biology (2009), doi:10.1016/j.cub.2009.06.060

I wrote about the two sides of our brains in April for Discover. Now some of the scientists whose research I highlighted have an article of their own in Scientific American, focusing on the ancient evolutionary origins of specializations in each hemisphere. So if you still have interhemispheric cravings, check it out!

Not too long ago I was interviewed for episode of the radio show Radiolab. Jad Abumrad and Robert Krulwich led me to a windowless cubicle where they then grilled me for a long, long time. From that interrogation, they produce a medley in which I say:

“Sloppy, sloppy, noisy, chaos, jumble, chance, sloppy, sloppy…”

Fortunately, they also saved a little more of our conversation, which was on a topic near and dear to my heart: the noisiness of life. It’s a subject I discuss at some length in my book Microcosm (ahem–paperback coming out on July 14–ahem). To wit: if you think that down at the level of molecules and atoms our bodies are just regular clock-like devices that go tick-tock-tick-tock, you’d be wrong. It’s a sloppy, noisy process, out of which it’s amazing that the regularities and predictabilities of our lives emerge.

The episode that Jad and Robert produced, called “Stochasticity,” (listen here) looks at the many roles chance plays in our life–from the level of cells, where I tend to lurk, to the myth of the hot hand in basketball.

Of course, like any self-absorbed starlet, I must say now that some of my best work was left behind on the cutting-room floor, or at least inside somebody’s hard drive. It was inevitable, given how cool and multi-faceted the mystery of biological noise can be. For example, I talk about noise filters on Radiolab, but I didn’t talk about one of the most important ones, which keeps signals clear in in our brains. If you want to read more, check out this piece I wrote last year for Wired. And I also didn’t get to explain that noise isn’t just something to get rid of, just an unalloyed bad thing. In fact, life has evolved to use noise to its advantage. Even E. coli knows how to play the odds like a skilled gambler, as I explained last year in the New York Times.

And if you want to head straight for the scientific literature behind this story, a great place to start is with the wonderfully-named 2008 review, “Nature, Nurture, or Chance: Stochastic Gene Expression and Its Consequences” (pdf at author’s site)

[Image: jaxpix on Flickr, via Creative Commons Licence]

Mind wandering is the subject of my new column for Discover. Far from just useless mental static, mind-wandering actually creates a distinctive pattern of activity in our brains–a pattern that suggests that it may actually be playing a crucial role in our mental life. Check it out.