Untethering the Brain

For my new  “Matter” column for the New York Times, I take a look at a new idea to explain that mystery between our ears. Our brains are enormous for our body size, and our minds are capable of extraordinary feats of cognition. Two neuroscientists have offered up a hypothesis that links these two facts, suggesting how an increase in brain size could have led to a change in how the brain is networked. Check it out.

You may also want to check out P.Z. Myers’s critique of the “tether hypothesis” on his blog Pharyngula. He raises some important questions about the idea, based on his own experiences as a neuroscientist. I’m puzzled, though, why he decided to kick it off with this swipe at me:

I suppose it helps to be at Harvard. It also helps to have a combination of subjects — evolution and the human brain — that Zimmer has written about in the past. It helps to have a paper with lots of very pretty diagrams — the authors’ hypothesis is professionally illustrated. It’s also a good idea to have a vast sweeping explanation for the exceptionalism of the human brain…You know what you don’t need? Data, or a hypothesis that makes sense.

I had no idea that Harvard had such a power over my feeble powers of judgment. Or that I am so vulnerable to pretty pictures.

What I thought happened was this: the tether hypothesis comes from Randy Buckner and one of his postdoctoral researchers, Fenna Krienen. I was long familiar with their work on mapping human brain networks, having visited them a few years ago when I wrote a story about the aging brain. Buckner was new to Harvard when I visited him, having made a name for himself beforehand at Washington University–which mysteriously failed to prejudice me against him.

After my visit, Buckner and his colleagues went on to do other important studies on the structure of the human brain, which they published in leading neuroscience journals. When I saw Buckner and Krienen’s new paper in the journal Trends in Cognitive Sciences, I did not, in fact, say, “Ooh, pretty pictures, ooh Harvard!” I said, “Scientists with a proven track record expanding their work on human brains to a comparison to other species. Interesting.”

Since I’m a journalist and not a neuroscientist, I also contacted outside experts. For example, I contacted Chet Sherwood of George Washington University. Now, I suppose Myers would think I’d be scared away because Sherwood isn’t at Harvard, but I actually am capable of recognizing that he’s an expert on mammal brain evolution who is familiar with the tether hypothesis–and therefore someone whose opinion should matter to me.

It turned out, as I mention in my article, that Sherwood found the tether hypothesis to be an exciting idea. He is intrigued by how it can potentially explain a lot about the anatomy and function of the human brain in a relatively simple way. That’s the sort of comment that makes me think that a paper would make for an interesting column.

It doesn’t surprise me that another scientist–in this case, Myers–disagrees. That’s how science works; recognizing that, I’ve included plenty of critics in my articles over the years. What does surprise me is that Myers would use a scientific critique to impugn my capacity as a journalist.