Reviewed by Bob Williams
by Carl Zimmer
Carl Zimmer, writer for Discovery magazine, and easily the magazine’s outstanding contributor, has collected with extensive rewriting for this book pieces mostly from the magazine. His decision to issue this as a Kindle avowedly reflects his wish to make the book easily accessible to interested readers. This is an unusual decision, perhaps prescient, although, except for the vision impaired, possibly premature. A Kindle hasn’t the ease of handling of the printed book, and references are difficult from the lack of numbered pages.
In the first of 15 parts into which Brain Cuttings is divided Zimmer invokes Darwin’s fascinating book, The Expression of the Emotions in Man and Animals. He describes it briefly and points out that Darwin was naïve in his methods, however little that marred his work. The facial expressions were and are a sophisticated communication device and Zimmer examines how elaborately contemporary scientists study the phenomenon. He justifies this on the basis that the expressions are the outward manifestation of processes within the brain, and that they constitute as it were the external hull of invisible transactions.
In the next chapter he considers the extent of the brain. Where does brain stop and a supposedly external world begin? The answer is not as simple as it first appears. To decide on the obvious, that it stops at the outside of the skull, ignores the relationship between brain and tool; this relationship introduces measurable modifications of neurons that make the obvious decision questionable.
Zimmer conducts us through a world that possesses many of the qualities of fantasy. For example, we keep track of time, more or less through the medium spiny neurons eavesdropping on the cortex. This could easily be the subject of a ballet by Merce Cunningham and John Cage.
Some knowledge of the brain arises from study of defects in its operation. The dominance of the mother or the father in a particular stretch of DNA suggests that the brain is genetically determined. Anesthesia provides additional possible clues to the activity of the brain. Zimmer describes the brain as a mass transit system rather than a device with separate on and off switches. This mass transit system can be modified when the question is a matter of identifying persons. In this situation sparse-coding networks appear to be the operative mechanisms.
The gross physical brain is itself a source of wonder and interest. It consists of two hemispheres that appear identical. The two hemispheres communicate with each other but one will have functions more strongly under its control compared to the other. The physical symmetry does not establish a functional symmetry, and the removal of one hemisphere causes the survivor to take over its functions.
Why does this marvelous mechanism with its million of interconnections work the way it does? More correctly, why does this fabulously complex brain that we possess sometimes not work very well? Zimmer reports the efforts of scientists to report on the wandering mind. The experiments are well devised and the results, of small explanatory value, at least measure the phenomenon. Not for the first time does Zimmer suggest that despite our best efforts, the brain has impenetrable secrets.
Monkeys are fairly good at working with numbers, but the edge of the human animal resides in the human capability to deal with precision on the one hand and with symbolic inferences on the other.
The speed of thought has become an outmoded expression although the variability is great. “In some ways evolution has fine-tuned our brains to run like a digital superhighway, but in other ways it has left us with a Pony Express.”
The longest piece revolves around Ray Kurzweil, the visionary computer specialist who has announced a future of immortality on the installment plan and whose pronouncements are as much substantial as silly. He is a baffling figure that Zimmer cannot altogether dismiss. Other researchers in related fields have coincidently achieved certain parts of his design and Zimmer is exceptionally gifted in describing their accomplishments against the background of Kurzweil’s extravagant fancies, many of which despite their prophetic power resemble the musings of a quack.
The study of the brain today does not permit definitive conclusions. It is intriguing to see what is being done and the how of it is fascinating. I have spent most of my reading in e-books lately and find that the standards are not as good as for the printed book. In Brain Cuttings many expected words are left out with no major effect on the readability, but I found Zimmer’s reference to a zebra fish that seemed to be some kind of bird unsettling.
Zimmer introduces each piece with a broad consideration, almost a stage setting, as a background to his description of contemporary scientific research and thought. He has written a book that makes every reader feel smarter than is probably true and he does this with ease and elegance. An enjoyable book.
About the Author: Bob Williams is retired and lives in a small town with his wife, dogs and a cat. He has been collecting books all his life, and has done freelance writing, mostly on classical music. His principal interests are James Joyce, Jane Austen and Homer.