December 27, 2006

Reader response

Today's mailbag has a couple of interesting reactions to my little dramatic exercise, "Shakespearing the reader's brain". In response to the discussion of denominal verbs in Act I, Susan H. wrote:

Although there were many things that bothered me about the Presbyterian Church in which I was raised, the final straw was the minister's use of denominal verbs. Specifically, he would say things like, "we shall fellowship together."

I found it so offensive that I became an Episcopalian as soon as I arrived at university.

I hate to tell you, Susan, but you might need to migrate to another denomination. The recent Christmas Message of the 26th Presiding Bishop of the Episcopal Church, the Most Reverend Katherine Jefferts Schori, begins this way:

God loved us so much that he came to dwell among us, to tent among us in human flesh... [emphasis added]

The bishop's message ends by reminding us that "God continues to be birthed in fragile opportunities that will need to be nourished and tended by others".

Now it's true that Shakespeare used tent as a verb ("The smiles of Knaues / Tent in my cheekes, and Schoole-boyes Teares take vp / The Glasses of my sight", Coriolanus, Actus Tertius). And the OED lists birth as a transitive verb in U.S. dialectal use, with citations from 1906. But that kind of authority has not been enough to redeem the verbal forms of dialogue, access, and so forth -- this is a matter of individual conscience, after all, not susceptible to earthly principalities and powers. One suggestion: a quick scan suggests that Richard Dawkins' writing is largely free of unexpected denominal verbs.

But perhaps post-collegiate maturity has brought you enough tolerance to turn the other cheek, linguistically speaking, and to await other denominal verbs in a spirit of ecumenical acceptance. We might even say, purely in the interests of exciting our brains and helping us stave off old-age forgetfulness, that you could "cheek it".

Meanwhile, Jim G. was inspired by Act II to imagine a bright future for event-related potentials in the arts:

I am delighted with Mark Liberman's report of the neuroscientific evidence of creative wordsmithing, which reinforces what I tell myself we always knew about good and bad art: P600 events without N400 reactions.

Now, if only you guys will add more of the search for quality to your usual discussions of the mechanics and the history.... Maybe we can get the eegheads to find specific ERP events for triteness and coarseness... Just imagine: the Academy of Motion Picture Arts and Sciences might award Oscars based on EEGs of a sample audience watching the various films. Imagine real quality triumphing over the buzz factor.

Wasn't that in one of Woody Allen's movies?

Seriously. there's an interesting idea implicit in Jim's joke, which is that when you measure cerebral blood flow or neurologically-generated electromagnetic fields, you learn something that is truer, or more reliable, or in some other way of higher quality, than what you learn by asking people questions or observing their behavior. So far, I'm afraid that the facts are the opposite way around. You can get much more reliable and also much more nuanced information about how people deal with linguistic form and meaning from a wide variety of old-fashioned methods, starting with introspection and self-report, and continuing with (direct and indirect) experimental methods such as reaction-time measurements, gaze tracking, corpus statistics and many others.

That's not to say that functional brain imaging isn't worth doing -- it enriches the available evidence in important ways. But EEG/ERP, MEG, fMRI and PET are all relatively crude tools, with poor signal-to-noise ratio and poor temporal resolution (fMRI, PET) or spatial resolution (EEG, MEG), usable only in highly artificial situations, and incapable of measuring many key features of neural activity.

Jim's joke also depends on another fallacy, which is that measuring people's brains somehow elevates their responses out of the domain of social science -- where we're dealing with a sample from a socially and culturally variable population -- and into an empyrean realm of psychic absolutes. I commented on this widely-held view in an earlier post with respect to a study of sex differences in humor ("Flacks and hacks and Hitchens", 12/14/2006):

... the subjects in this study were 10 males and 10 females, average age 22, recruited at Stanford Medical School. [...]

But the paper's conclusions aren't about how Stanford med students' brains work. Instead, the conclusions are about what "males and females share" and what "females ... activate .. more than males" and so on.

Would anyone accept a characterization of Americans' political or religious opinions, or their product preferences, based on a sample of 10 first-year Stanford medical students? Would a newspaper try to predict a national election from such a sample? Would a network executive rely solely on such a sample in estimating the response to a new comedy show? You'd have to unusually stupid or gullible to believe predictions about the population at large that are based on ten 20-somethings enrolled at Stanford.

So why are Dr. Reiss and his colleagues willing to treat such a sample as acccurately characterizing the nature of the brain responses to humor of human females and human males, taken as a whole? And why does a savvy political journalist like Hitchens accept this extrapolation as truth?

There's an implicit assumption here that from the point of view of humor a brain is a brain -- or rather, a male brain is a male brain, and a female brain is a female brain. Age, education, personality, cultural background, occupation -- none of that matters, and so none of that needs to be controlled for. We neuroscientists don't need no demographically balanced samples, we're measuring brains. Determining men and women's responses to humor is treated like determining the melting points of bismuth and antimony -- all you need to do is to measure a pure enough sample. There's some residual recognition that statistical variation needs to be averaged out, which is why N=10 rather than 1. But if you think of the enormous variation in either sex's sense of humor -- surely as richly varied as their attitudes towards politics or shampoo -- the assumption of sexual uniformity seems very strange.

Even stranger than the idea of impersonal neuro-humor is the notion that absolute measures of "triteness" and "coarseness" could be derived from the brains of a sample audience watching a movie or a TV show, thus eliminating the "buzz factor" in favor of "real quality".

Unless, of course, you take the view that all brains share the same underlying aesthetic dimensions -- which being facts about brains, and therefore biological, must be universal, like loudness or pitch -- and that everyone also shares the same basic propensities to map sensory experiences onto these neurological scales. It's only later that things get individual and messy, when the brain's responses are shown to the subjective homunculus in the Cartesian theater, who muddies the aethetic waters with preferences and actions:

"Hmm, that's 7.3 out of 10 in neuro-triteness, and 8.7 out of 10 in neuro-coarseness, so..."

A) "yucch, turn it off immediately before I lose my lunch!"
B) "OK, one episode was interesting, but I don't think I'll make a habit of it."
C) "wow, let's buy the boxed DVD set of the last five seasons!"

On this view, you could determine the true aesthetic value of an experience, in effect, by zeroing in on what the brain is doing before the mind kicks in. This seems like a very odd picture to me, but I guess it's an example of the way that a lot of people (including some scientists) think about brain research. If so, this would help explain why even people who should know better find that irrelevant statements about the brain turn bad explanations into satisfactory ones.

Posted by Mark Liberman at December 27, 2006 07:36 PM