Roots

I have lately become impressed with the what's going on in the brain. Learning more about the small details, I wind up asking myself about the "big picture" that these details reveal. I'm a visual kind of guy, so I'm thinking about a picture something like this:

Neural network in the brain

That picture is showing main connections only - myelinated "high speed" connections. The actual picture would be a packed tangle of axons and dendrites - for example, the massive wad of connections that make up the "white matter" in the brain, connecting (on average) each neuron in the neocortex with 1,000 other neurons.

White Matter in the Brain is a Wad of Connections

Where else do we see something like that?

Roots in the Forest Floor

There is a tangle of roots under our feet in the forest floor. We usually see the big ones that manage to break the surface and threaten to trip us up, but the network is much more extensive, especially in a thriving "old growth" forest. We have recently found that trees are not just sucking up water and nutrients. They are communicating with each other through their root system.

I'm a sucker for analogy. It's natural for me to ask: what is the brain "sucking up" through its "root" system. Obviously, the nervous system is in the business of conveying information from the world (and inside the organism) to other parts of the organism - especially the central nervous system. Information is also being conveyed in the opposite direction - not only to allow us to wiggle our fingers but also to modify how our eyes "see" the world (roughly helping the eyes see things that "matter").

We, as conscious beings, owe our consciousness to our roots in the real world. Our root system is designed on a very fine level to suck every bit of precious information from that world. To take the example of the ganglia* in the eye, we have 20 different ganglia types, extracting 20 different types of information from the raw information provided by the retina. It's easy to think of a few types of information that might be extracted, such as a 2-dimensional map of 3 different colors plus black and white (that's the 4 different types of photoreceptors--rods and cones--in the eye). We imagine that like the image going from our camera retina to the camera memory. What else? At this point, we can only guess. Maybe something like this:

• Day and night - time to sleep, time to wake
• Faces
• Weather
• Sun location - where am I? What time is it?
• Movement - comparison with one image with another a fraction of a second later
• Repeating shapes 
• Shapes of known objects
• Basic "camera" adjustments such as the need to increase or decrease exposure, image sharpness, saturation ...
• Compensation for the fact that the eyes are always moving 

We are all familiar with the experience that something we are looking for, perhaps our car keys, mysteriously seem to "pop out" from the jumble of other things in our field of view. Just two hops from raw data from the photoreceptors - a few centimeters -- our brains extend neurons that are hungrily extracting "meaning". "Upstream" from the visual system, we find brain systems looking for enemies, mating opportunities and chances to maintain status in the group.

Like a tree, we are sucking up what we need to survive. We have left it to the plants and the animals that eat plants to take care of our nutritional needs. We live or die on our ability to extract information from the world. Being "rooted" in the world is perhaps the best metaphor to help us think of our relationship to the world - the "mind-body problem".

Our "roots" analogy can be applied at another level: DNA and evolution.

We may regard the entire history of evolution as the story of life groping in "reality" to find a niche, a body plan and a pattern of reacting the environment that "works". 

Similarly, we can use the same concept with human languages.

We may think of languages as groping through the world of human experience (E) to find an effective way to share the matrix of experience within a culture. Shared experience is a necessary (but not sufficient) condition for what we might call a scientific apprehension of "reality". In any case, this capability seems to be important enough for nature to devote significant parts of our central nervous system to communicate using language.

Of course, the idea applies to the worlds of imagination such as religion, where an entire culture gropes in vain for some kind of sensible, self-consistent way of speaking about a realm that is entirely fictitious.

The Chaotic Imaginary World of Christianity

* You can learn about ganglia in the visual system from Episode 39 of Rob Reid's "After On" Podcast "Restoring Sight to the Blind"