From Bacteria to Bach and Back

From Bacteria to Bach and Back

"Brains .. are composed of billions of idiosyncratic neurons that developed to fend for themselves, the brain's functional architecture is more like a fee market than a politburo hierarchy where all tasks are assigned from on high. The fundamental architecture of animal brains (including human brains) is probably composed of Bayesian networks that are highly competent expectation-generators that don't have to comprehend what they are doing. Comprehension - our kind of comprehension - is only made possible by thee arrival on the scene quite recently of a new kind of evolutionary replicator - culturally transmitted information entities: memes." - page 176

Among many implications flowing from this statement is the idea that our "minds" float in a sea of "culture". They are a virtual machine running the memes installed in the brain, simulating a small part of the affordances on offer in the culture we are born into. To put it another way, you cannot speak of "mind" without "culture".

Roughly speaking, this means that the "I" Domain (Working memory) can be thought of as interfacing with the "M" world without needing to get into the details of how the brain works. The first 175 pages "Bacteria to Bach" make this case in detail.

We can still make meaningful distinctions between memes - those that are readily accessed or even "installed" in the brain, those that are fresh, those almost forgotten, those available with a bit of casual research, those beyond the natural capability of the brain in question (IQ), those that don't make sense in a language "installed" in the brain and so on. The M-Domain is richly structured and complex but we don't need to muddy the waters by getting bogged down in the equally rich and complex structure of our brains: the statement above explains brains well enough for our purposes. We can make a lot of progress simply by talking about the memes we "know" or, to put it another way, memes that can be called into working memory and used as "things" or executed as "subroutines".

Other quotable quotes:

• words are the DNA of cultural evolution" (p. 179)
• Don't be afraid of a little metaphor; it won't bite you, but you should always make sure you know how to cash it in for unvarnished fact when you feel the urge (p. 189)

The Brain As an Amazing Symmetry Computer

I have a coffee cup in front of me (I usually do). If I rotate it or move or see it in different light it my brain automatically makes me experience it as the same cup. If you have ever tried to make a computer figure this out, you will see how astonishing this is. What's more, the cup will be seen as the same cup tomorrow and the same as the cup that I washed a week ago (or is it two weeks? The point is, that doesn't matter). This is symmetry under a transformation in time and space. It takes place so automatically that most of us will go through our entire lives without thinking of it at all.

There is another, related, trick that the brain does. It makes me "see" the cup as a form. A form is a bunch of "stuff" that is more or less arbitrarily treated as the "same thing". My dog is quite capable of seeing a flying tennis ball as a "thing" that can be snatched out of the air, but she seems to be uninterested in the "things" shown on our TV screen. This is just to point out that selection and recognition of "things" is a brain function and not "out there" in the real world.

Brains which make an isomorphic transformation (or I suppose a "reverse" transformation) are able to manipulate the "things" of the mind as if they are "things" of the real world. Brains are good at detecting relevant things and picking them out of the hurricane of sensation that presents itself to working memory in every second. You could say this allows working memory to "compress" the world into a very small set of "things". I don't expect the cup to turn into a cat, but I would quickly notice if it did. Otherwise, it can just sit on my desk and play a small part in what I perceive as my surroundings.

From Bacteria To Bach and Back (Dennett) provides a detailed exploration of how our minds come to recognize "things" and how the "thinginess" of the world arises from relevance rather than raw reality. An ant somehow recognizes certain things but presumably doesn't "know" it's doing it or even that it's an ant. "Consciousness" is not required to recognize "things". The brain has inherited this very ancient capability from the dawn of life and has had billions of years to perfect it. That's why it's so good at it. In Dennett's terminology, symmetry computations are a "competence" of brains: a competence without comprehension or, one might say, a pre-condition of comprehension. Dennet makes another subtle point: this competence doesn't depend on any kind of representation of the world in the ant's head or our head. In other words, we need not look for the set of neurons or synapses that "represent" my coffee cup in my brain. I picture the cup as a result of a result of a fantastically nested and fractal computation that the brain does "on the fly", a computation this is best described in Hofstader's"Surfaces and Essences"/ This computation relies mainly on analogy which is a special case of symmetry. This is why I refer to the brain as a "symmetry computer". It uses symmetry to "compress" all experience into "merely" a few billion connected neurons.