Monday, May 14, 2012
EVOLUTION: CONTINUOUS AND CUMULATIVE
Antonio Damasio’s “Self Comes to Mind: Constructing the Conscious Brain” came Saturday morning and I haven’t done anything since but read it. He is much more of a splitter than Gazzinaga, who tends to be a bit of a lumper; he is quite continental (lives mostly in Paris); and in the end has a bit to say about society. The basic idea he works along is that the brain has evolved new parts which have lifted our simple mammalhood into humans, but every part from the spine “up” (the new parts stack up that way, then begin to bulge forward which is why we have foreheads) remains in play. This is where he is most brilliant (IMHO as I falter along behind him), nothing once evolved is discarded. A brain is cumulative. This is not like the evolution of species, which discards losers.
But our evolving understanding of the brain means that we must constantly re-negotiate what it is we’re looking at. Instead of letting Gazzinaga’s idea of “the Interpreter” which is so helpful and suggestive or even “the Confabulator” which I find equally so, stand alone while investigating his results, Damasio (partly to fend off the ghost of the homunculus) keeps going back and back to reconsider what he calls “CDRs” and “PMCs”, which means “covergence/divergence regions” and “posterior medial cortices.” These clusters of interacting neurons correspond roughly to the various mysterious sub-centers that sort out information from the senses before sending it to Gazzinaga’s Interpreter where his Confabulator fills in the gaps. (Brains tend to fill in gaps by seeing what’s not there, and to leave things out when they have no categories for them and are focusing on other information.)
Damasio notes that when anatomists tease out little parts of the brain that seem to have certain duties and relationships, they are often grouped into CDR’s or PMC’s either by what they seem to do or by their proximity or connection to other bits. (Not so much because of their shapes.) But incredibly delicate tests (they can now trace the changes that mean “information: dit-dash-dit-dit-dash” leaving the nerve cell, traveling down the axon, and then the return message (boy waiting at the door while you read the telegram) back up the second cell’s axon.
It turns out that the idea of a cell assigned to each concept (what is called “grandmother” cells, not because they are grandmothered in but because the cell presumably contains all the info about grandmother as though each cell were a file) is not exactly wrong, but is combined with “whole brain activity,” possibly dissected into some aspects: face here, smell there, voice some other place, so the files are “facial recognition,” “smells,” “voices”-- which means they must be reassembled into Grandmother on cue.
He explains that thinking is topographical (We draw those diagrams and outlines and schemas on napkins and the backs of envelope all the time!) quite literally. If the surface of the brain, now so rumpled, were flattened out ever so gently, it would be in layers and each layer is marked off into chessboard squares where the electrochemical thoughts act like pixels on a TV screen, combining and recombining into patterns. One layer is touch, one is sight, one is hearing -- all being fed by the CDR’s and PMC’s. The one for awareness of the body even amounts to an anatomical outline of the body, though the parts that are really important and rich with info are bigger than the other parts. Gazzinaga is good about this.
But the huge contribution of Damasio, and he knows it, is his insistence on keeping emotion/feeling present at every level and showing how the higher levels evolve out the lower ones. There will be much to work on and think about here. My own preoccupation is relating this to the feeling of the Holy that Mircea Eliade so brilliantly identified.
To Damasio, an emotion like love is not a separate newly-sprouted organ, but an interplay of many phenomena from the first ability to record tactile events, through the instinctive bonding that keeps baby animals in their nests and burrows and then following their mother; then the ability to pick out one individual from one’s own kind and bring that proper person back to memory (so the ducklings don’t wander off after Konrad Lorenz), recognize him or her and think about them when they are not present; to accompany the pleasure of a physical relationship with a saturating emotional complex; and on up the complexifying until reaching moral faithfulness in the part of the brain just over the eyes. There’s probably a book in that.
Damasio is aware of another story, that of the individual fertilized blastosphere at the mercy of the womb environment, evolving according to the chemical code of its genome (shaped by the previous millenia) as it is able, then born in that tunnel adventure of emergence (EMERGENCE! Ah, emergence! A key concept!), set free into a new set of family circumstances that shape the baby, and finally into increasing participation into society.
If the code had enough integrity, if the parenthood were encouraging, if no traumatic mishaps (individual or global) interrupt, that individual survives. SURVIVAL Damasio sees as the individual’s task and specifically the brain’s task. Not just avoiding grizzly bears, but also keeping the internal environment within the bounds that allow life: enough air, water, food, temperature, acid/alkali balance, blood sugar balance, etc. etc. in a state of HOMEOSTASIS which describes and maintains the survivable parameters. So it turns out that the course I took long ago at PSU about why rats get thirsty was relevant after all. (Today we’re wondering why rats get fat -- their brains have lost control of homeostatic use of food.)
Damasio is an optimist and lives a privileged life with a sound track (a background feeling level) that permits the idea of progress. For others of us who live closer to the basics, the music is beginning to have a foreboding theme. Brains evolve and they do not stop evolving because the environment, including society, is always pressing on people to survive. What allows survival is what determines evolution.
If we are killing off our best and brightest young men -- not just in Middle Eastern wars but on the streets -- what are we doing to the gene pool? If the women are having to raise their babies alone -- not just in Mississippi but in Ethiopia -- or, worse, if the children are having to raise themselves without education except what it takes to merely get enough calories in a day, what is that doing to the evolution of brains? Will the development of the mirror cells that allow compassion atrophy and disappear? Will a new ruthlessness override it? It is not enough to evolve people. We must also evolve our society.