Thursday, October 22, 2015

Some things I've read lately; singing whales, beautiful theories and cargo cult neurosceince

Here are some things I’ve run across lately that might be of more general interest.

First, in the long line of singing animal posts (Go Mice!!), here is a nice review of the largest bass-baritone critters: whales. The piece compares their songs with that of birds. They are amazingly similar once one speeds up the whale stuff and adjusts the register or slows down the bird stuff and adjusts the register.  It appears that complex vocalization is something that sits there in many species quite far removed from one another on the evolutionary bush ready to evolve when the circumstances are propitious. So, mice, some birds, whales, humans, and I am sure, much more.

Second is this paper by Frank Wilczek (Nobel winner) on beauty in scientific theory. He identifies two properties that make a theory beautiful: (i) it has symmetrical laws and (ii) it is “exuberant.” 

Now, current linguistics is not physics, but it seems to me that theories do have aesthetic virtues that are revealing. We have no conception of symmetry (or none that I know of) but we do value theories that have fewer moving parts and are less “fine tuned” than their competitors. Thus one reason to value “reduction” (as in e.g. reducing anaphora or control to movement (te he!)) or unifying phrase building and displacement as instances of Merge is that it provides a prettier theory than one where all of these phenomena are treated as sui generic. Here “pretty” means more constraining and more explanatory. Here’s a corollary: one reason to be suspicious of the injudicious use of grammatical features is that they allow too much fine tuning of our accounts and explanation is at odds with fine tuning. Pretty theories explain, and that is part of what makes them pretty. For the interested there is a pretty good discussion of the vice of fine tuning and its relation to explanation in Steven Weinberg’s (another Nobelist) recent Whig history of modern physics (here).

The exuberance condition is also a good sign that your theory is onto something. I am sure I am not alone in being surprised that some account generalizes to phenomena it was not constructed to account for. Maxwell describes this (according to Wilczek) as “get[ting] more out of them [i.e our theories, NH] than we put into them.” Again exuberance and reduction/unification go hand in hand, as does the avoidance of fine tuning. As Wilczek puts it:

The second source of beauty in the laws of physics is their productivity – what I call their exuberance. Just a handful of basic principles generates an astonishing wealth of consequences – everything in the physical world! You can write the equations of the core theories of physics – known as the standard model – quite comfortably on a T-shirt. To paraphrase Hertz, they give back far more than we put in.

It is interesting that the real sciences consider such aesthetic discussions worth having while less mature disciplines (linguistics?) seem, IMO, to find them generally embarrassing. Maybe it is a mark of a field’s explanatory achievements that it is willing to entertain aesthetic considerations in its evaluation of truth.

Third, and last, here is a terrific rant on current neuroscience and how much we understand about the brain. Not much according to this piece.

The first point on C. Elegans is worth thinking through carefully. If it is correct (and I have heard the point made before) that we have the entire inventory of neurons and how they are wired up for C. Elegans but we still have no idea how its brain works then this should lead us to question the utility of complete wiring diagrams as the holy grail of neuro understanding. I really don’t know if this rant is accurate (though several neuro types I respect did not declare its contents BS), but if it is anywhere near the truth, then there is little current reason for thinking that the demand that cognitive claims should justify themselves in neuro terms should be afforded any respect. From what I can tell, rather the reverse should hold. We have pretty good stories about some domains of cognition (linguistics being one very good story) and next to nothing about neural mechanisms. So which should be cart and which horse? Here’s the rant’s useful warning:

So, the next time you see a pretty 3D picture of many neurons being simulated, think “cargo cult brain”. That simulation isn’t gonna think any more than the cargo cult planes are gonna fly. The reason is the same in both cases: We have no clue about what principles allow the real machine to operate. We can only create pretty things that are superficially similar in the ways that we currently understand, which an enlightened being (who has some vague idea how the thing actually works) would just laugh at.


  1. The third thing reminds me of a point Dan Dennett has made in response to the idea that evolutionary processes produce only 'apparent' design rather than actual design (he says it is actual design, only by an unintelligent designer; natural selection). If we're going to categorise things into those things that are designed against those that are merely 'designoid', then a prime example of the latter category would not be an exquisitely adapted organism, but rather a drawing of the Millennium Falcon from Star Wars. It sure gives the impression that somebody knows how to build a complex, functioning spaceship, but we know it's just an illusion that relies on mimicry of actual technology and what we expect it to look like.

    The issue with mapping neural connections and watching them fire seems rather like trying to pass off the Millennium Falcon blueprint as the real deal. It's pseudo-understanding pretending to be genuine understanding as the superficial complexity of the map and its activity is taken to be equivalent to a functional description which, of course, it is not, but we more easily dupe ourselves in this case because the maps are drawn by brain cartographers rather than graphic artists.

  2. Symmetry and in particular symmetry breaking is one of the underlying themes of Stabler and Keenan's Bare Grammar book.

    As for the unwillingness to discuss "esoteric" matters, that strikes me as a simple case of worrying about public perception. The more elevated and secure your social status, the less of a damn do you have to give about what other people think. Physics is the poster child of modern science, so they can do whatever they want. Linguistics does not have that luxury, and thus (some) people want to make sure we appear serious, level-headed, studious and facts-oriented --- i.e. what the layperson considers scientific.

    Finally, the only baffling thing about C. elegans is that many researchers still don't appreciate how large the chasm between hardware and software actually is. We have perfect knowledge of our computer hardware, but that does not mean that you can reverse-engineer Windows (or even the much simpler Solitaire) by studying the circuits of your processor. One and the same program can have very different machine code instantiations, and one and the same piece of machine code can do very different things: solving a shortest path problem, for instance, always takes the same form, but what you're actually computing depends on what that path represents. That's why theoretical computer science abstracts away from the hardware, and that's also why computer science and electrical engineering are two very distinct fields.

    There have been arguments that the brain is not a computer in the common sense because it is not general-purpose, that is, its circuitry cannot be freely reprogrammed. I'm not sure I agree with that statement (our computer hardware is not fully general-purpose either, that's a useful abstraction). But even if we grant that difference, I don't see how it lessens the gap between hardware and software in a meaningful way. But who knows --- Colin has sometimes argued that language is in some sense a hardware-dependent device, so maybe I'm missing something crucial.

  3. I intended to add a link to a post on vocalization that relates to the first entry above. However I had trouble finding it. I finally did so. Here it is:
    The linked to paper discusses how vocalization is just sitting there waiting to be activated.