I Am a Strange Loop

about the brain — I leave the wet, messy, tangled web of the brain to the neurophysiologists.”

Another part of me, however, wants to reply, “Of course I think about the human brain. By definition, I think about the brain, since the human brain is precisely the machinery that carries out human thinking.”

This amusing contradiction has forced me to ask myself, “What do I mean, and what do other people mean, by ‘brain research’?”, and this leads naturally to the question, “What are the structures in the brain that someone could in principle study?” Most neuroscientists, if they were asked such a question, would make a list that would include (at least some of) the following items (listed roughly in order of physical size):

amino acids

neurotransmitters

DNA and RNA

synapses

dendrites

neurons

Hebbian neural assemblies

columns in the visual cortex

area 19 of the visual cortex

the entire visual cortex

the left hemisphere

Although these are all legitimate and important objects of neurological study, to me this list betrays a limited point of view. Saying that studying the brain is limited to the study of physical entities such as these would be like saying that literary criticism must focus on paper and bookbinding, ink and its chemistry, page sizes and margin widths, typefaces and paragraph lengths, and so forth. But what about the high abstractions that are the heart of literature — plot and character, style and point of view, irony and humor, allusion and metaphor, empathy and distance, and so on? Where did these crucial essences disappear in the list of topics for literary critics?

My point is simple: abstractions are central, whether in the study of literature or in the study of the brain. Accordingly, I herewith propose a list of abstractions that “researchers of the brain” should be just as concerned with:

the concept “dog”

the associative link between the concepts “dog” and “bark”

object files (as proposed by Anne Treisman)

frames (as proposed by Marvin Minsky)

memory organization packets (as proposed by Roger Schank)

long-term memory and short-term memory

episodic memory and melodic memory

analogical bridges (as proposed by my own research group)

mental spaces (as proposed by Gilles Fauconnier)

memes (as proposed by Richard Dawkins)

the ego, id, and superego (as proposed by Sigmund Freud)

the grammar of one’s native language

sense of humor

“I”

I could extend this list arbitrarily. It is merely suggestive, intended to convey my thesis that the term “brain structure” should include items of this general sort. It goes without saying that some of the above-listed theoretical notions are unlikely to have lasting validity, while others may be increasingly confirmed by various types of research. Just as the notion of “gene” as an invisible entity that enabled the passing-on of traits from parents to progeny was proposed and studied scientifically long before any physical object could be identified as an actual carrier of such traits, and just as the notion of “atoms” as the building blocks of all physical objects was proposed and studied scientifically long before individual atoms were isolated and internally probed, so any of the notions listed above might legitimately be considered as invisible structures for brain researchers to try to pinpoint physically in the human brain.

Although I’m convinced that finding the exact physical incarnation of any such structure in “the human brain” (is there only one?) would be an amazing stride forward, I nonetheless don’t see why physical mapping should constitute the be-all and end-all of neurological inquiry. Why couldn’t the establishment of various sorts of precise relationships among the above-listed kinds of entities, prior to (or after) physical identification, be just as validly considered brain research? This is how scientific research on genes and atoms went on for many decades before genes and atoms were confirmed as physical objects and their inner structure was probed.

A Simple Analogy between Heart and Brain

I wish to offer a simple but crucial analogy between the study of the brain and the study of the heart. In our day, we all take for granted that bodies and their organs are made of cells. Thus a heart is made of many billions of cells. But concentrating on a heart at that microscopic scale, though obviously important, risks missing the big picture, which is that a heart is a pump. Analogously, a brain is a thinking machine, and if we’re interested in understanding what thinking is, we don’t want to focus on the trees (or their leaves!) at the expense of the forest. The big picture will become clear only when we focus on the brain’s large-scale architecture, rather than doing ever more fine-grained analyses of its building blocks.

At some point a billion years or so ago, natural selection, in its usual random-walk fashion, bumped into cells that contracted rhythmically, and little beings possessing such cells did well for themselves because the cells’ contractions helped send useful stuff here and there inside the being itself. Thus, by accident, were pumps born, and in the abstract design space of all such proto-pumps, nature favored designs that were more efficient. The inner workings of the pulsating cells making up those pumps had been found, in essence, and the cells’ innards thus ceased being the crucial variables that were selected for. It was a brand-new game, in which rival architectures of hearts became the chief contenders for selection by nature, and on that new level, ever more complex patterns quickly evolved.

For this reason, heart surgeons don’t think about the details of heart cells but concentrate instead on large