Friday, May 18, 2012

Can a Rat Walk Down "Memory" Lane?

(by guest blogger Carrie Figdor)

In my first post I introduced the issue of rising public anger at science due to the apparently cavalier way in which empirical results affecting issues the folk hold dear -- silly things like human nature and the nature of the universe -- are being disseminated. I'd like to provide examples of the forms this miscommunication can take, which due to my philosophical interests focus on neuroscience (although the Krauss-Albert tussle over the term "nothing" is clearly germane).

Sometimes miscommunication is one-off. While researching the paper described below, I came across a 1956 Scientific American article in which the scientist, reporting his results to the public, credits B.F. Skinner with refining the methods for measuring pleasurable and painful feelings (Olds 1956). I thought this was hilarious (Skinner?!) until I tried to come up with a good explanation for why he would describe Dr. Radical Behaviorist this way, let alone in a news outlet where the audience is not casual and space is not at such a premium. I couldn't, or at least not in a way in which the scientist came out looking good. (Note: this criticism has nothing to do with the brilliance of the research.) Again, while searching for a related cognitive neuroscience article in the peer-reviewed Journal of Comparative Neurology, I was taken aback to find it in a special issue entitled "The Anatomy of the Soul". Were they serious? Were they joking? Which answer is less bad?

But a systematic source of foreseeable public confusion stems from the use of folk psychological terms to report neuroscience results in professional contexts. Such terms are coopted into neuroscience discourse to report results and translational implications and recycled back into public discourse via the popular science press without mention of possible shifts in meaning. In this paper I compared uses of some terms ("reward", "fear", and "memory") in bibliographically linked studies and found that it is at least an open question whether syntactically identical terms taken from the folk mean what they ordinarily mean, or even whether they remain semantically identical across studies and over time. Unless the public is clearly warned not to assume these words mean what they ordinarily do, miscommunication is pretty much guaranteed.

Here's one example. In a 1954 study of brain areas associated with "reward" with rats, "reward" is behaviorally defined as a stimulus associated with increased frequency of response, and electrical stimulation in certain brain areas is "rewarding in the sense that the experimental animal will stimulate itself in these places frequently and regularly for long periods of time if permitted to do so.” (Olds & Milner 1954) By the time of a related 2005 fMRI study on romantic love, human subjects who self-report being madly in love are scanned while passively viewing photographs of their loved ones. The reported result is that areas of the brain associated in earlier studies (including the 1954 rat study) with motivation to acquire a "reward" are among those associated with being in love. But is love "rewarding" the way electrical stimulation of the brain is "rewarding"? Is a photograph passively viewed by a lover a "reward" the way an electrical brain stimulus self-administered with increasing frequency a "reward"? There's certainly self-stimulation to photographs in the vicinity, but my guess is that this sort of "reward" and "rewarding" feeling isn't what subjects felt in the experiment. So while I don't doubt the septum and caudate nucleus are part of a "reward and motivation" system, I'm not at all sure what "reward and motivation" means that would cover all these cases. Of course, the public has no way of figuring out (and should not be expected to) that "reward" and cognates have undergone shifts in meaning since such terms were seized from the public sphere.

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