So today I am going to write about a tree structure, prompted in part by the tree of life at reference 1 and in part by the opening of the book of Genesis, which goes, in the Alter translation: ‘When God began to create heaven and earth, and the earth then was welter and waste and darkness over the deep and God’s breath hovering over the waters, God said …’. Which, digressing, leads one to think that some of the chaps who contributed to the Old Testament knew what they were talking about, more than two thousand years ago though it might have been.
So babies are born with functioning brains, but not having had much sensory input to bite on. Their brains have not exactly been idling, but they have not had much to bite on. Then all of a sudden, all kinds of sensations kick in. And according to this story, in the beginning, these sensations are all rather undifferentiated. There might be a sort of memory in that one sensation can be distinguished from another, but the sensations are not yet organised in the way that ours are. There is no distinction, for example, between sight, hearing, taste and touch. Or smell. While thought is as yet absent and doesn’t usually ever have a smell – although there are, as so often in matters of this sort, exceptions.
But over time, the baby’s brain learns to sort all this stuff out. Perhaps the first divide – taxonomists are keen, these days, on binary trees, with just two branches at each divide – is between taste and everything else. Then everything else divides into touch and everything else. Until, after some months, we have the full panoply of senses, carved up in a more or less adult way. And consciousness of a sort. And scientists of the future can spend happy years working out exactly how and when this tree comes to be.
Fairly early on, perhaps before birth, the brain had already learned to associate a quality – effectively a small real number, positive, negative or zero – with these sensations. Some sensations are good and some are bad. To some we are pretty much indifferent. Very important for deciding quickly enough what to do about the tiger which has jumped in through the kitchen window. Some people call this number the valence of the sensation, by analogy, I suppose with the valence of the chemists.
Then there is a bit of a pause while language kicks in. And then classification proper can kick in – with language, while perhaps not essential, certainly being very helpful. The baby learns the different sorts of tastes, the different sorts of smell, the different sorts of colours. The different sorts of feelings about things, feelings being a subtle combination of quality and something else (and if you fancy a bit of DIY on this one see reference 2). Lots of classification.
Then there are some people who get into a bit of a muddle, who never get to fully sort out the difference between, for example, what most of us call taste and what most of us call hearing.
This story can be disturbed by a different sort of reality. The fact that some things do not classify into trees very well and are much better described in some low dimensional Euclidean space. So colours can be nicely described as points in a three dimensional space, with the three dimensions standing for red, green and blue. The fact that some things do not divide in a binary way. That it might make more sense to divide taste, for example, into six basic categories (say) at the outset, rather than try to sort out a binary tree. The history of exactly how the baby comes to know the six categories, the evolution of the six categories is not important; it is the six categories themselves which are important.
This story is possibly further disturbed by the fact that horses are born in a better shape that we are, able to see and to walk more or less from the off. I, along with plenty of others, also believe that they are conscious, at least in some sense. So maybe whatever consciousness they have develops too fast for the sort of tree I talk about above to have the time it needs to grow.
Nevertheless, to be continued in due course. Perhaps an episode covering the other end of life, that is to say how all this classifying falls apart as we get older or become demented?
Reference 1: http://psmv3.blogspot.co.uk/2016/02/tree-of-life.html.
Reference 2: http://www.theemotionmachine.com/.
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