Do Neurons Literally Have Preferences?

Carrie Figdor has been arguing that they do.

Consider these sentences, drawn from influential works of neuroscience (quoted in Figdor forthcoming, p. 2):

A resonator neuron prefers inputs having frequencies that resonate with the frequency of its subthreshold oscillations (Izhikevich 2007).

In preferring a slit specific in width and orientation this cell [with a complex receptive field] resembled certain cells with simple fields (Hubel and Wiesel 1962, p. 115).

It is the response properties of the last class of units [of cells recorded via electrodes implanted in a rat’s dorsal hippocampus] which has led us to postulate that the rat’s hippocampus functions as a spatial map. ... These 8 units then appear to have preferred spatial orientations (O’Keefe and Dostrovsky 1971, p. 172).

These are completely standard, unremarkable claims of the type that neuroscientists have been making for decades. Figdor suggests that it's best to interpret these claims as literal truths. The verbs in these sentences work like many other verbs do -- "twist", "crawl", "touch" -- with literal usage across a wide range of domains, including organic and inorganic, part and whole.

Figdor's view sounds bizarre, perhaps. People literally have preferences. And rats. Maybe frogs. Not trees (despite 22,000 Google hits for "trees prefer", such as "Ash trees prefer moist, well-draining soil for optimum growth"). Definitely not neurons, most people would say.

One natural way to object to Figdor's view is to suggest that the language of neurons "preferring" is metaphorical rather than literal. I can see how that might be an attractive first thought. Another possibility worth considering is that maybe there are two senses of "prefer" at work -- a high-grade one for human beings, a thin one for neurons.

Figdor responds to these objections, in part, with technical linguistic arguments that I am insufficiently schooled in linguistics to evaluate. Does conjoining human and neuronal cases of "prefers" pass the zeugma test?

However, from seeing others' reactions to Figdor -- she gave a talk here at UCR a couple weeks ago -- I'd say it's not a fine sense of technical linguistics that drives most people's rejection of Figdor's claim. (In conversation, she says agrees with me about this; and in newer work in progress she is de-emphasizing the technical linguistic aspects to focus on the bigger picture, including how terms evolve over time in deference to scientific usage.) What gives folks the heebie-jeebies is the thought that "preferring" is a psychological notion, and so if Figdor is saying that neurons literally have preferences, she appears to be saying that neurons literally have minds or psychological states. And we certainly don't want to say that! (Do we?)

Figdor is not some far-out panpsychist who believes that neurons tingle with experiences of delight when they receive the stimuli they prefer. But she is far out in another way -- a more sensible and appealing way, perhaps. Once we see the actual source of her radicalism, we can start to appreciate the importance and appeal of her work.

It's natural -- common sense -- for us to approach the world by dividing it into things with minds (you, me, other people, dogs, birds...) and things without minds (stones, trees, pencils, fingernails). Reflecting on intermediate cases, such as various types of worms, one might sense trouble for a sharp distinction here, but vagueness along a single spectrum of mindedness isn't too threatening to common sense. The essential difference between the minded and the un-minded remains, despite a gray zone.

Figdor's picture challenges all that. If what she says about "prefer" also goes for some other important psychological terms (as she thinks it does), then mentality spreads wide into the world. Some psychological terms -- "prefer", "decide", and "habituate" are her examples, to which I might add "seek", "learn", "reject", and many others -- appear to spread wide; while other terms, such as "meditate", "confess", and "appreciate", might apply only to humans (or maybe a few other species). Each psychological term has a range of application, and the terms that are more liberally applicable will attach to all sorts of systems that we might not otherwise tend to regard as privileged with any sort of mentality.

Figdor has taken, I think, a crucial step toward jettisoning the remnants of the traditional dualist view of us as imbued with special immaterial souls -- toward instead seeing ourselves as only complex material patterns whose kin are other complex patterns, whether those patterns appear in other mammals, or in coral, or inside our organs, or in social groups or ecosystems or swirling eddies. Some complexities we share and others we do not. That is the radical lesson of materialism, which we do not fully grasp if we insist on saying "here are the minds and here are the non-minds", demanding a separate set of verbs for each, with truly "mental" processes only occurring in certain privileged spaces.

With that thought in mind, let's go back to "prefer". Do neurons literally prefer? I don't know whether the linguistic evidence will ultimately support Figdor on this particular case, but I think we can approach it evenhandedly, letting fall wherever they may the technical tests of metaphor and polysemy and other considerations from linguistics and philosophy of language -- figuring that of course some of our mental state verbs literally refer to patterns of behavior that spread widely, and at different spatiotemporal grain, across the complex, multi-layered, dynamically evolving structures of our world.

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Carrie writes:

Thanks to Eric for posting on my work-in-progress and the opportunity to clarify a few things. First, the technical linguistic stuff is actually my attempt to understand why it could possibly strike anyone as "natural" or "reasonable" to think these uses are metaphorical. Who "naturally" thought Hubel and Wiesel intended their descriptions of their data to be metaphorical? To the contrary, the cry of "Metaphor!" reflects not an astute semantic analysis of their uses but an automatic response to my claim that they should be interpreted literally: "They just can’t possibly be literal." The idea that they are metaphorical is actually one of the weakest semantic alternatives to a literal view.

That said, Eric is correct that I am not a radical panpsychist. Rather, I’m interested in a plausible, non-ad hoc explanation of the ever-expanding uses of psychological language throughout biology at all levels of complexity. Basically, I think psychological concepts are transitioning to scientifically determined standards for proper use, leaving behind the ideal-rational-human, anthropocentric standards we now have. There’s a lot more to that story, and I hope to make it public very soon.

Telepathic Cyborg Rats!

...

It was only a matter of time.

The next step, of course, is aerial transmitters atop our heads which allow direct human brain-to-brain interface without all that slow-paced language business (as envisioned in Churchland 1981).

HT: Nathan Westbrook.

...

What the Large Print Sayeth the Small Print Denieth

(by guest blogger Carrie Figdor)

In my last post I noted how professional science journals and other peer-reviewed venues coopt folk-psychological terms to report experimental results. Popular science reporters are not introducing these terms as metaphors to describe neuroscience results in laymen's terms; the laymen's terms are right there in the original articles. Nevertheless, it is a common response to blame public misunderstanding of science results either on the popular science press, or on the public's lack of science education, or both.

For example, Racine and colleagues (2005) coined the term "neuro-realism" to label the way popular science coverage of fMRI studies "can make a phenomenon uncritically real, objective or effective in the eyes of the public." One of their examples of neuro-realism is a 2004 report in The Boston Globe: "[B]ecause fMRI investigation shows activation in reward centers when subjects ingest high-fat foods, one reads, 'Fat really does bring pleasure'." But after examining how the term "reward" is used in peer-reviewed neuroscience articles, it is not clear why the Globe reporter is thought to be miscommunicating the science, let alone responsible for the miscommunication.

Similarly, if adding neuro-babble to an excerpt of a psychological explanation makes non-experts rate the explanation more highly (Skolnick Weisberg et al. 2008), shouldn't the response be: "Hey, we're the gods of knowledge about reality! Maybe, just maybe, with great power comes great responsibility -- including responsibility for our language!" The public might well be excused from not being able to distinguish added neuro-babble ("Brain scans indicate that the "curse" happens because of the frontal lobe circuitry known to be involved in self-knowledge") from serious claims in research articles ("Several fMRI studies reported increased prefrontal and parietal activity during lie ... Based on these findings, deception has been conceptualized as inhibition of truth and generation of lie mediated by the prefrontal cortex, with truth being a “routine” response mediated by the posterior structures." (Langleben et al. 2005)

Instead, where popular science reporters may be blameworthy is in their abdication of their role as professional skeptics. In a 2006 analysis of 134 popular science articles on fMRI studies -- appearing in the popular press between 1994-2004 -- Racine and colleagues found that "the vast majority of articles (n = 104, 79 percent) were uncritical in tone, whereas twenty-eight (21 percent) were balanced or critical", and that specialized sources were less critical than general news sources. In short, the ferociously aggressive skepticism to which political stories and figures are routinely subjected by the press is nowhere to be found. The Scientific American spoof may be a sign that this free ride is about to end.

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.

Twilight of the (Scientific) Gods?

(by guest blogger Carrie Figdor)

Is it a mere coincidence that the Metropolitan Opera is offering its latest Ring-cycle blitz at about the same time as my stint as an invited guest blogger for Eric? The skeptic in me warns against hasty judgment, yet I think there's an interesting relationship between the two series. Isomorphisms come cheap, but the best things in life are free, so even a cheap isomorphism is worth more than the best things in life.

Before I go on, I'll introduce myself: I'm a philosopher of mind and metaphysician at the University of Iowa, in the state where Herbert Hoover and Captain James T. Kirk are local notables and gay marriage is legal. I'm also a former Associated Press newswoman, hence a professional gadfly twice over. The news story I'm interested in maps Wagner's distinction between ordinary mortals and the gods to our distinction between "the folk" and scientists, who occupy the most powerful intellectual position in our culture. This story (but not Wagner's) is that the folk are getting deeply and inchoately pissed at the scientific gods. In this series of posts, I want to explore this anger and what it means for science, philosophy and the folk.

One unmistakable expression of it came on April 1, 2012, when Scientific American published a spoof of neuroscience claims, carefully labeled as such just in case the joke was not immediately obvious just by reading it: "Neuroscientists: We Don't Really Know What We're Talking About, Either." It began: "NEW YORK—At a surprise April 1 press conference, a panel of neuroscientists confessed that they and most of their colleagues make up half of what they write in research journals and tell reporters." I suspect the editor had inserted a less generous percentage in an earlier draft.

A second came on April 23, 2012, when The Atlantic Monthly included the following paragraph in an interview with Lawrence Krauss that was sparked by the Krauss-Albert affair (a clash of titans worthy of Wagner):

Because the story of modern cosmology has such deep implications for the way that we humans see ourselves and the universe, it must be told correctly and without exaggeration -- in the classroom, in the press and in works of popular science. To see two academics, both versed in theoretical physics, disagreeing so intensely on such a fundamental point is troubling. Not because scientists shouldn't disagree with each other, but because here they're disagreeing about a claim being disseminated to the public as a legitimate scientific discovery. Readers of popular science often assume that what they're reading is backed by a strong consensus.

I'll borrow from The Atlantic to elaborate the issue: Because the story of neuroscience or physics (i.e., science) has such deep implications for the folk, it is important to tell that story to the folk correctly and without exaggeration. And yet it is not being told that way. The Atlantic is troubled because the public is being fed what may or may not be a crock, not because the gods are clashing (which is only to be expected). Scientific American effectively accuses neuroscientists of being full of it -- half the time, but which half? -- and by adding that "either" practically screams that its staff is getting really tired of being played.

Both missives from leaders in the mortal sphere imply that the folk are not being treated as they believe they should be. This is all the more annoying when your offerings -- um, taxpayer dollars -- are rabidly sought by these gods in the form of NSF grants. And so the question arises: how much longer will, or should, this situation go on? What can be done to change it, for the good of the folk and science?