Consciousness and how it got to be that way

Wednesday, June 30, 2010

Dreaming About Former Stress Experiences

It's a cliche that in the industrialized world, adults tend to dream about missing exams in high school or college. You know the ones - you have a test or a class you have to be in but you don't know where it is, the hallways don't make sense, your school or the buildings aren't the way you remember them, and it's a disaster. You wake up and you're maybe even mildly amused; thank goodness you'll never have to deal with that again. Why do we seem only to have these dreams when we're no longer in that situation?

After a 13-year hiatus from education I began medical school at age 35, leaving a career in biomedical research consulting. At one point prior to starting med school I joked to a colleague that I could no longer laugh off those missed-exam dreams because there are many, many more quite real exams in my future. But what I am amused by is that now, I no longer have missed-exam dreams, and instead I've started having anxiety dreams about situations associated with my pre-medical school career. Usually, in these new dreams, I'm arriving late at an airport only to find out that my flight has just left. That this change occurred less than a year after I left that career certainly suggests that there's some mechanism which pegs anxiety to stress experiences that we no longer have, or that are associated with some earlier phase of our identities.

What could be going on here? There are lots of people that change careers and/or go back to school, so has anyone else had this experience?

Friday, June 25, 2010

Hupa is Not Unique Among Languages in its Use of Verbs

In a sketch of a neurolinguistic theory I posted previously, I mentioned a possible empirical problem with the theory. Specifically, I posit that the basic neurological unit of language is the noun. If this were the necessary structure of language based on human anatomy, a non-noun-based language would falsify the theory. The Wikipedia article on Hupa previously stated:

Morphologically, it is remarkable for having an extremely small number— perhaps less than one hundred— of basic (monomorphemic) nouns, as nearly all nouns in the language are derived from verbs.

I have long been interested in Hupa as a result of this statement. The first question we might ask is whether such a dramatic innovation is restricted to Hupa or in fact appears in some form in other lower or Pacific Athabaskan languages. There is no report of such structures in Upper Umpqua or the Rogue River languages.

Once you read the grammar and vocabulary of Hupa published by P.E. Goddard, 1905, barely half a century after their first contact with Europeans, the answer was clear. The claim about Hupa's use of verbs and paucity of nouns, which is not referenced, is totally inconsistent with Goddard's work. Goddard lists 130 nouns straight away in the first 20 pages. Not all are morphophonemic, but the non-compound morphemes for the obligately affixed nouns seem to all be unique. Furthermore there is discussion of verb nominalization on page 21-23, and while the morphology seems to be more elaborated than in Western Indo-European languages, it's nothing as dramatically novel as this statement, certainly not showing that "nearly all nouns in the language are derived from verbs." In fact Athabaskan languages in general have elaborate verb morphology, though again, they don't replace nouns.

For a time I had thought that Hupa was a real-life example of the fanciful verb-based language of Tlön fantasized by Borges in Tlön, Uqbar, Orbis Tertius. But it's not. It's worth pointing out that there does seem that there are some innovations of Hupa, relative to other Athabaskan languages, but this is to be expected from a language isolated for centuries with close trading relationships with an Algonquian language (Yurok) and a probable isolate (Karuk). Certainly the differences are not so profound.

I subsequently revised the Wikipedia article. In the meantime continue to look for languages that falsify the neurolinguistic sketch. One interesting possibility is that we might find dramatic differences in language based on geography with phylogenetic patterning. That is, is there something different about Andamanese + New Guinean + Australian languages (earliest out of Africa) vs. sub-Saharan African languages vs all other languages? I'm not asking whether there could be differences based on language-descent, which there necessarily will be; I'm asking the far more controversial question of whether they may be genetic innovations that result in different wiring and therefore differences in language structure. So far we have not found differences so profound as to warrant speculating about population-wide differences in the underlying hardware. If we ever do find differences in a language or group of languages as dramatic as the one that had been suggested here, or that Daniel Everett suggested with Piraha (which also appears to collapse under scrutiny), I submit that it might be profitable to look for anatomic and genetic differences. Such diversity of language and neurology would absolutely be a windfall to understanding the physical basis of language and cognition.

As an aside, I have been to the Hoopa Nation in Northern California several times. It's absolutely beautiful country and I highly recommend a visit. Unfortunately the Hupa language is not a living language, although it is being preserved by the efforts of Danny Ammon and others who make their resources available for the rest of us.

Trinity River south of Hoopa, California, by Trinityalpsphoto

Cranial Blood Flow Differences Between Populations?

A provisionally published paper in BMC Research Notes by Farhoudi et al uses transcranial Doppler to investigate flow rates in major cerebral arteries. They found that the averages for their sample from northwest Iran were higher than previously described norms.

The numbers are presented as-is with no p-value, so caution is in order in thinking these are necessarily real (though Farhoudi et al don't make any claims beyond presenting the numbers.) What is immediately interesting is whether there are real population differences and what that means for investigative methods like fMRI studies. There's also the question of whether there are clinical correlations (different stroke rates and outcomes in some populations?) or even behavioral/cognitive connections - though for that last question I'll hope that Razib Khan picks up the story.

A Competition Mechanism for Attention

A nucleus in the midbrain of owls is found by Asadollahi et al to encode salience (i.e., relative strength) of visual and auditory stimuli. This is strong support for the existence of the previously theorized salience map and is a big step in the study of attention. Nature paper here.

Future questions: how is remote sense data (visual-auditory) integrated with contact data (touch, pain and taste)? How are attention conflicts resolved; that is, when an agent voluntarily wants to focus on a stimulus that is weaker and no more irregular than those around it? In the case of humans trying to focus on one visual stimulus known to be important despite sensory distraction, might we predict inhibitory projections from the temporal cortex to this nucleus or to its projections?

Sunday, June 13, 2010

DNA Testing and Inconsistent Laws

The following seems a little bass-ackwards: FDA doesn't regulate companies that sell bullsh*t medicine - that is, "herbal supplements" which these highly profitable companies strongly imply can treat disease (and are sometimes unsafe, just like real pharmaceuticals.) But this same agency is now warning DNA testing companies that they're out of compliance, even for products that aren't intended to diagnose disease. I have two 23andMe kits sitting in my office right now that I haven't sent in yet, and I'm going to be pretty annoyed if FDA's ruling affects them. I suspect I'm not the only one. Following FDA submission rules is enormously expensive and time-consuming, and most of these companies don't have the resources to do it. Unless we think of a sensible solution, good-bye DNA testing industry.

This personal genomics/personalized medicine revolution everyone is talking about won't get her if it's made illegal. The problem is not that there should be no regulation, it's that there should be consistent, non-stupid regulation, and the U.S. is going to damage a domestic industry that will be very important in the near future early in its development.

[Added later: Alex Tabarrok at Marginal Revolution says it much more elegantly and directly: "The idea that the FDA can regulate and control what individuals may learn about their own bodies is deeply offensive and, in my view, plainly unconstitutional."]