In my effort to find non-machine metaphors for the brain, I remembered a presentation some years back by a neurologist who described the brain as jello with fruit in it. His purpose (and all metaphors have purpose—see Metaphors We Live By by Lakoff and Johnson) was to illustrate how trauma damaged specific parts of the brain. It does have the consistency of jello and the fruit in it, say grapes, represents neural centers, concentrations of grey matter, i.e., nuclei of nerve cell bodies, such as the amygdala or substantia nigra. If you jerk and shake the bowl, you can see that the grapes jostle more, being denser and heavier, and thus, if they were neuronal nuclei, would be at risk of tearing apart from their axonal and dendritic connections. A notable example of this would be a boxer, say Muhammad Ali, who endured many punches to the head. The damage arose in just this manner, as different nuclei were repeatedly jarred and torn from their place in the connectome. The old phrase is “punch drunk” because of the slow, slurred motor patterns due to this trauma to lower motor centers in the brain.
So there you go, another metaphor. Now I want to go back to my metaphor of late June, the brain as river delta. I have always revered estuaries; they are places of great fertility, seemingly so messy as to be chaotic, a lovely ecology engendered by the meeting of fresh and salt waters. Deltas are estuaries that have evolved and grown over time due to the strength of the inland flow. Here is a false color image of the Mississippi.
This image conjures for me, among many other thoughts, the evolution of the brain. Different islands, i.e., cell nuclei, arise from the deposition of detritus carried down the river while the water, i.e., connectome flow, continues through various channels until it slows and merges with the ocean. The size and shape of deltas depend upon many factors but especially the river that meets the ocean. Here is an image of the Nile delta.
Deltas, like brains, develop embryologically and then accrue experience with changing structures. Deltas, like brains, evolve over geologic time, as land forms change and shift, creating and modifying watersheds. Consider just these brains, the shark and human brains with the rat and cat brains as intermediaries, to see this thought illustrated over the course of evolution.
Unlike deltas, brains have evolved through the process of natural selection in the genetic domain. The hominid brain derives from a watershed of genetic flow through the life forms of our ancestors that has changed and enlarged, thereby improving our viability and contributing further to our particular current in the genetic pool. Our brains, unlike computer circuits (as useful as that metaphor is), are more delta-like in their disorderliness. The fertility of our minds is more estuarine than machine. (I will address those whose brains are more jello like (& no fruit) later if and when I consider our cultural idiots, e.g., current flag ‘controversy’?).
Before traveling on, dive into the metaphor a little deeper. Remember these lyrics from David Byrne and the Talking Heads?
Take me to the river
Throw me in the water
And how about these from Toni Childs?
Where’s the ocean?
Where’s the moments I once knew inside my heart?
Where’s the ocean for us, where’s the ocean for me?
. . . . .
The ocean’s here, the ocean’s here.
And now travel on, if you will, to meet with us, as Van the Man sings, into the mystic. And again I remind myself that my purpose is to understand the biological roots of our humanity, all of it, especially art and imagination.