Old Timer's Disease

Now that the little darlings are both sleeping, eyeballing each other from across the room now and then, I have time to read again. One of the things I've been reading is an article in a Scientific American I have had lying around for god knows how long. They carry a few centerpiece articles, many of which tend toward physics and computers, neither of which holds my interest for very long (the exception being a really interesting piece this month - scratch that - the cover says November 2005! on a naturally occuring nuclear reactor in a uranium mining pit in Ghana). The piece I am reading now presents some of Todd Heatherton's cognitive neuroscience research into the making of self-awareness and self-concept, features believed to be unique to humans. He believes the implications of his work may shed light on treatments for Alzheimer's.

The author makes the obligatory reference to William James and Phineas Gage, two individuals all intro psych students ought to know, then goes on to superficially identify the area of the brain Heatherton and colleague Michael Gazzaniga have been studying - the medial prefrontal cortex. This area of the brain isn't really the center of "self" as Heatherton points out (just as it is ridiculous to say that Broca's and Wernicke's areas are together the seat of that other uniquely human trait - language). He believes it sort of acts like the grand central station of all experiences and perceptions that produce a sense of self.

Some far more theoretical research by Matthew Lieberman focuses on two brain networks that feed into self-awareness: the reflexive and reflective systems. The first makes associations based on statistical probabilities and is slow to form because it takes many experiences for this system to become established. Once it is, it works powerfully to reduce the thought needed to answer such questions as "Am I intelligent?" for a college professor or "Am I dexterous?" for a steamboat operator who navigates the narrowest canals on the Illinois River (silly reference to an old article in the Atlantic and also to Mitch, there's a lot you don't know about me!) These sorts of self-relevant questions can be answered automatically without having to think about the evidence. To me, this sounds like a fancy new way of talking about the same old thing: heuristics. Incidentally, the only Nobel Prize awarded to a psychologist (Daniel Kahneman, who won it for economics) was for a body of work that ultimately comes down to heuristics.

The article eventually considers how this body of work could shed light on the evolutionary origins of self-awareness and self-concept, and it is here that I can provide some critical commentary. First, they point out the medial prefrontal cortex (located in the neocortex, who Robin Dunbar pointed out is three times larger than it should be for our human body size) is "one of the most distinctly human brain regions" (a vacuous statement in my opinion) and is also larger in humans compared with other primates (of course the author keeps that human-animal boundary in check by stating that it is larger in humans than nonhuman primates).

The interesting tidbit identifies that this portion of the brain is loaded with spindle cells, which also happen to form the plaques associated with Alzheimer's Disease. An article in yesterday's U-B discussed new research into this debilitating condition. The thing that stuck with me is that no one knows whether these spindle cells have ballooned out of proportion much like cancer cells or whether the afflicted brain just fails to prune them.

In any case, given that other primates don't develop Alzheimer's and don't have enormous neocortexes, it is natural to wonder why humans do. The author paraphrases Heatherton who alludes that the answer is that humans have to have self-sense because we had to cooperate to gather and share food, which requires trust, and that he says requires a sense of self. At this point, my brain, having heuristically navigated the content of my tome of knowledge, produced a sudden urge to cry bullshit. First, plenty of other animals with miniscule neocortexes, and presumably tiny medial prefrontal cortexes cooperate (meercats, Belding's ground squirrels, schooling fish, etc. etc. without having a self-concept, at least as judged by whether they can be estimated to recognize themself in a mirror, a test that is the gold standard for this sort of thing. Most apes of a certain ages and some dolphins appear to recognize themselves in mirrors, but so far no monkey has, save for few cotton-top tamarins whose hair was spray painted with Manic Panic day-glo pink in Marc Hauser's lab. I'd predict that a few large brained birds like crows and parrots, especially the notoriously smart keas, would self-recognize, but that's about it for the animal world. Of course, I have criticized this standard for self-concept for as long as I've been teaching primate behavior. Second, one doesn't need aself-concept to truct others. As reminded by a recent HBES conference talk, oxytocin, a hormone, facilitates trust, and that is one ancient chemical. Even voles have it.

Perhaps our need to cooperate drove the evolution of the neocortex. I don't doubt that humans developed an immense brain because it helped us cooperate more efficiently and effectively than competitors and previous hominids, but I do doubt that cooperation requires a self-concept. The SciAm article alludes to the idea that self-concept drove cooperation which in turn drove the evolution of the human brain.

I don't buy it when there are so many other more compelling theories. See for reference Geoffrey Miller and Robin Dunbar.