National Geographic

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:

What does it take to get Carl Zimmer to review your research in the New York Times?

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.

There are 10 Comments. Add Yours.

  1. John Kubie
    December 27, 2013

    PZ Meyers makes some good points, but mostly misses the mark.

    For example, he says, “The question is, what made our association cortex expand in our evolution, …? Those are good questions, and I’d be curious to see them answered. Too bad this paper doesn’t.”

    This is not the question addressed by the paper. The paper assumes expansion due to evolutionary pressures, asks what non-linear changes could be expected. Their proposal: untethering.

    Myers also gives himself creds due to his background in comparative, developmental neuroscience. Also, Myers description of his work on development presents what I consider a weak argument. He asks why should long distance connections be lost? My answer: wiring costs. A few long distance connections, as in the animals he studied, might be OK. The huge number of long-distance connections across a 2D cortex would greatly increase the amount of white matter in the large brains. If I recall, Sam Wang has done some calculations.

  2. Constance Avery
    December 27, 2013

    Petty comments have no place in scientific critique, especially going a bit off topic to do so. Meyers comments about Carl Zimmer were unjustified.

  3. Costard
    December 27, 2013

    Don’t take PZ personally; there’s been a lot of bitterness on his blog lately since his application for position of fourth horseman was rejected.

  4. Pan Outeast
    December 27, 2013

    Ouch, that seems uncalled-for. If he thinks the hypothesis is baloney and feels you should have been more cautious, fair enough. But as it is he makes you sound like a serial offender, which is… puzzling. It’s not as though he doesn’t know you – you used to share the same blog-home, you’ve been co-contributors in other fora, I guess you must have met, and (I looked) he’s name-checked you numerous times and never negatively till now. Maybe PZ’s been spending too much time in the ring? Punch-drunk and taking swings at passers-by? Or could it be something to do with the whole divided loyalties thing that came with the various political fooferallies over at ScienceBlogs?

  5. MosesZD
    December 27, 2013

    That he should make unwarranted and unjustified personal attacks against you, as if you’re some dimwitted hack, should be of no surprise to you or anyone in the Science Blogging, Skeptical or Atheist communities. After all, this is what the demagogue does when he/she seeks attention and decides to, par for the course, engage in polemics-for-attention instead of engaging in rational thought and discourse.

    I’m only surprised that it’s taken this long for Myers to find your bridge to burn it down. Like he has with so many others in the Science Blogging, Skeptical and Atheist spheres.

    Last, please stop calling him a scientist. Myers is NOT a scientist, he’s a biology teacher at a 4-year college. The truth be told he hasn’t done anything in science in twenty years and even then, he wasn’t exactly top-drawer material.

    [CZ: I considered removing this comment for violating my comment policy. But then I decided to let it stand as an example of the sort of comment I don't want on this blog. You don't get to hunt on this blog for an excuse to make ad hominem attacks. Taking the high moral ground when it comes to personal attacks and then calling someone a demagogue, not a scientist, etc., speaks for itself. Just to reiterate: When I see a comment that crosses the line, I take it down and send a warning to the commenter. On rare occasion, I have to ban people who just don't want to listen and wish them well out on the great big Internet.]

  6. Dan
    December 27, 2013

    I don’t know what his beef is against you (perhaps he thinks you’re too accomodationist?) but the personal attack was just misguided. I’ve read several of your books and am very impressed with your scholarship. Plus, you are a very clear writer. I enjoy your book on evolution (pretty pictures…) and I recommend it to anyone interested in an introductory book on the subject.

    PZ’s far gone IMO and I haven’t read his blog for several years now. It’s all just internet drama, far-left politics, enemy-shaming, etc. I’ve moved on to better science bloggers.

  7. Robin Ford
    December 27, 2013

    Speciation occurs in internet journalism just as it does in other living organisms.
    
An initially common population begins to divide as it spreads and occupies a more diverse landscape.

    Gene transfer between regions becomes restricted as the interests of different groups diverge. Alleles favoured by one group are shunned in another.

    Each increasingly specific population either expands to fill a new and widening region, is replaced by the expansion of adjacent populations and/or is extinguished by challenges that it can’t resist.

    This grossly simplified ecological model does not, however, cover the occasional mutation that has little practical advantage but is nevertheless favoured within it’s own gene pool simply because, for want of a better word, it is sexy.

    Within the family known as Science Journalists, there are the communicators, the entertainers and the gossips.

    I trust Carl Zimmer and make regular time and space for “Matter” and “The Loom”, I don’t recall the last time I visited “Pharyngula”.

  8. Kit
    December 28, 2013

    I disagree with the claim that ’The human mind can carry out cognitive tasks that other animals cannot, like using language, envisioning the distant future and inferring what other people are thinking.’ – evidence indicates this statement is false. There is evidence dogs and certain birds can infer what others are thinking and can envision the future, whilst there are examples of language in dolphins and prairie dogs for e.g. See http://www.huffingtonpost.com/marc-bekoff/humananimal-relationships_b_4439038.html

    [CZ: For an introduction to what makes humans cognitively special, I'd suggest Thomas Suddendorf's recent book, The Gap.]

  9. Edward Gemmer
    December 28, 2013

    I wouldn’t be too surprised. If you read his blog, it is literally filled with personal attacks on anyone who says anything about anything. Not even trying to make an attack on Myers – just pointing out that is his shtick.

  10. Sterlingbird
    December 28, 2013

    I thoroughly enjoyed your NYT article, and I’m intrigued by their “tether hypothesis.” My intuition and personal experience has shown me that the mind can reach out beyond the brain. Every time I set a goal and work toward realizing and materializing it, my mind expands. I, of course, can not “prove” this.

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