Oliver Sacks and the Comforts of Metal

Oliver Sacks and Robin Williams on the set of Awakenings (brainpickings.org)

Oliver Sacks and Robin Williams on the set of the film Awakenings
(brainpickings.org)

I was first aware of Oliver Sacks with the publication in 1985 of his book The Man Who Mistook His Wife for a Hat. The descriptions of his mentally ill patients were as intriguing as the title. A few years later, Robin Williams played Sacks in Awakenings, the story of the kind and idealistic doctor who finds a drug that revives his catatonic patients at a hospital in the Bronx.

Sacks died of cancer in 2015. He had been writing for a few months for the New York Times about his struggle. One of these wrenching and beautiful pieces is “My Periodic Table.” In it, Sacks describes three aspects of nature in which he sees different sides of himself.

“Times of stress throughout my life have led me to turn, or return, to the physical sciences, a world where there is no life, but also no death.” With death approaching, “I am again surrounding myself, as I did when I was a boy, with metals and minerals, little emblems of eternity.” These include element 81, Thalium, a souvenir of last year’s 81st birthday; Lead, 82, for the birthday just celebrated; and Bismuth, 83. “I do not think I will see my 83rd birthday, but I feel there is something hopeful, something encouraging, about having ‘83’ around.”

(Reading this touched off my own memory of how, as a boy, I tried with my father’s help to collect all 92 natural elements. In a display case on the wall over my bed I placed some sulfur and carbon from my chemistry set, small bottles of hydrogen, nitrogen and other gases that I had made, and bits of lead, iron, and other metals. Bringing together in my room the building blocks of nature felt like a commanding achievement, though the final display came to only about 20 items.)

While Sacks finds consolation in the basic metals, he responds differently to the stars. About viewing the starry sky one night, he writes that “It was this celestial splendor that suddenly made me realize how little time, how little life, I had left. My sense of the heavens’ beauty, of eternity, was inseparably mixed for me with a sense of transience—and death.”

Lastly, when he “wanted to have a little fun” before beginning immunotherapy, he visited the lemur research center in North Carolina. “Lemurs are close to the ancestral stock from which all primates arose, and I am happy to think that one of my own ancestors, 50 million years ago, was a little tree-dwelling creature not so dissimilar to the lemurs of today. I love their leaping vitality, their inquisitive nature.”

A lively ancestor, mortality among the stars, deathless birthday metals—a sacred trinity of sorts, Sacks’ selection of holy companions. We select from nature according to our joys and fears. The chemical elements mean little to me now and I don’t have thoughts one way or the other about metals and their durability. But I share sometimes Sacks’ sense of feeling belittled by the stars; they do inspire awe, but in contemplating my life and death, I’m in need of something friendlier. For me, Sacks’ lemurs are on a better track. I find consolation by including myself among the mass of organisms of all kinds—not just humans—living and dying now, the wave of rising and falling life as the current of beings sweeps on, out of its billion-year past.

Stem Cells: How To Build and Maintain Bodies, Including Plants

Until recently, I didn’t know much about stem cells except that they produced other kinds of cells and that the medical research on them was controversial. In the context of the history of life, it turns out, their importance is as fundamental as you can get.

It took more than a billion years for the first cell with a nucleus to come together. Since then, the only reliable source for a new cell has been another cell. Every cell is an offspring. True for plants as well as animals.

An embryonic stem cell (Wikipedia)

An embryonic stem cell
(Wikipedia)

But while cells are specialized for one task or another, they are not always very good at dividing and reproducing. Muscle cells, blood cells, and nerve cells don’t reproduce at all. Other cells in the body divide only under some circumstances or only a limited number of times.

But reproduction is the stem cell’s specialty. When it divides, it produce another stem cell, ready for the next round, along with a muscle cell or blood cell or nerve cell or a cell of another organ. It looks the part for such flexibility—blob-like, unstructured, not committed until needed.

Stem cells are stationed throughout the body, small groups of them in each organ, like local hospitals on call to repair the sick and damaged. They are a profound piece of bodily engineering, a design for the long-term, like a futuristic car that carries little 3-D printers throughout the engine and chassis to create new parts and replace the old parts automatically.

In human embryos, in contrast to adults, stem cells literally build the body. When an embryo is only a few days old, its stem cells begin to form all—all—of the specialized cells needed in a body, some 200 of them.

In this root tip, the number 1 marks the relatively unstructured stem cells in the meristem. (Wikipedia)

In this root tip, the number 1 marks the relatively unstructured stem cells in the meristem.
(Wikipedia)

Plants have stem cells too. Located near the tips of the roots and stems in a layer called the meristem, plant stem cells divide into both specialized cells for the plant and additional stem cells. Stem cells are, in other words, the place where a plant grows.

One of the wonders of any living thing is the sheer variety of its parts, the inventory of its tubes, organs, fluids, surfaces, protrusions, electric circuits and rigid pieces. As we pause to appreciate this profusion, sing the praises of the smudgy cell that creates and repairs them all.

How Consciousness Might Have Evolved

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s3.amazonaws.com

Human consciousness. Our wonderful, crazy mind. Our personhood. And our quandary. Where did consciousness come from? How did it become part of us?

Michael Graziano, a neuropsychologist I’ve posted about before, writes in the June 2016 Atlantic about how consciousness might have evolved. He starts with the question that evolutionists ask about any feature of an organism: What is its adaptive value?

The answer, he writes, is that consciousness is a sophisticated solution to a difficulty that plagues the nervous system of all creatures: “Too much information constantly flows in to be fully processed.” It’s an old dilemma, with early fixes. Even before the formation of brains, nervous systems 600 million years ago enhanced certain nerve signals at the expense of others. The eyes of insects and crabs, for example, generate “an outline sketch of the world” as signals carrying data about where the edges of objects are  located come in stronger than other visual signals.

Then around 500 million years ago, a controller in the early brains of fish and reptiles began coordinating several senses at a time, “aiming the satellite dishes of the eyes, ears, and nose towards anything important.” The controller did so by generating an internal model, a set of information about the current state of the body parts, and predicting “how these body parts will move next and about the consequences of their movement.” If you had only a reptilian controller for a brain, you would look at the steps in front of you and the controller would check those signals against its model of where your legs ought to be to get you up the steps successfully.

But we have much more than a controller. Some mammals, including us, have the latest upgrade, the cerebral cortex. We can pay attention to something we are not even focused on at the moment—the TV in the other room, for instance—because our cortex can select what to select. What’s more, we can even be self-aware that we are doing so. “I’m not going to go in there, but he’s watching that news again” (my example). Humans can do this because our upgraded controller uses schemas, models of not only all that we know but also of our attention itself. Our brain tracks “what covert attention is doing moment by moment and what its consequences are.” This is where we get that self-aware voice inside us that tells us, “I’ve got something intangible inside me. It moves around from one thing to another and allows me to understand and remember.”

Such evolution of consciousness goes hand in hand with our social evolution, according to Graziano. Animals acquired the capacity to be aware of the mind of other members of their species. Social awareness and self-awareness have evolved “in tandem….We understand other people by projecting ourselves onto them. But we also understand ourselves by considering the way other people might see us.” Consciousness tracks and grows from our social life and our social self.

Graziano acknowledges that the schema theory of consciousness is still new, but he believes it “provides a general framework” for understanding consciousness and its evolution. It seems to me that it does so very well. It’s difficult for us to see our minds in physical terms because we have that voice in our head that insists, “Wow! I’m thinking and feeling all this!” Feeling this cerebral glow, we easily believe we carry an ethereal self, even an undying soul. But I think it’s the opposite conclusion that is exciting: that the splendor of consciousness is not as an outlier in nature but is a thoroughly earthly step in the series of small, accidental, pragmatic adjustments that is physical evolution.