Originally posted on 05-13-07
In the post on 05/11, I talked about the brain being a decision-making mechanism. An interesting thing about that is that the brain doesn’t know how it makes decisions, any more than it knows how it sees.
Our ability to think abstractly and to make tools has allowed us to look at how our brains work in ways we never could when we could only look from inside, and one of the areas most studied is vision.
There is a whole big chunk of the brain involved in vision, but none of the individual pieces knows what it’s doing. There are neurons that only fire when there are horizontal lines in our field of view, but they don’t have a clue what a horizontal line is—they get a stimulus, they fire. The output from this and other specialized neurons gets sent on to still others, and they fire when they are stimulated by a particular pattern of inputs. As multiple pattern-recognition neurons pass their signals along, eventually a combination of patterns reaches an area of the brain that deals with language, and the “tree” neuron fires, or maybe the “oak tree,” or “pine tree” neuron. These neurons don’t “know” what they are responding to—they just get stimulated and they fire. They may actually be responding to a memory rather than to a current stimulus.
The visual process doesn’t occur in a vacuum, of course. Other parts of our brains are monitoring our senses, the position of our bodies, etc. All this current sensory processing is occurring in the context of our individual histories, with all our previous experience of trees, along with our experience of all the other aspects of the present situation, and all of it put together results in “The Feeling of What Happens” when we see a tree.
That expression in quotes is the name of an excellent book by Antonio Damasio. I differ with him on some of his conclusions, which I’ve written about here, but his books have given me many wonderful insights for which I’m grateful.
A guy I used to work with once asked me what I was reading about, and when I said it was about how the brain works, he said, “Your brain is like the telephone: you don’t need to know how it works to use it.” True, but the more we know about how it works, the more strange and wonderful our experience of the world and ourselves becomes. It’s pretty amazing to be here.
Water Knows Granite