Beyond The Zonules of Zinn
A Fantastic Journey Through Your Brain
Not another book about the brain, surely?
There are many many books about how the brain works. Sometimes it seems like everyone who has ever thought or taught about the brain has written a book. And many of them are very good – plumbing the depths of our deeper drives; dissecting the differences between us; spewing out theories about intelligence, consciousness and mind. Some of them are not so good, but they all share the same central drive to discover how the brain works.
This book is different. I am fascinated by the richness of the story of how we studied the brain – or rather how our brain has studied itself. The earliest known written reference to the brain was probably made by the designer of the first Egyptian pyramid. The most important brain experiments were carried out in front of baying crowds in ancient Rome. And some of its most important parts were discovered by a man who also invented gin.
But there is more than just a little colour to be gained from looking at the mind this way. From the twenty-first century perspective, it is easy to forget one very important thing about the human brain. Of the fifty-or-so centuries in which we have pondered the brain, only in the last one have we been able to elucidate its inner machinations. For the previous forty-nine, we could study only one thing about the brain – its structure. So for most of that time, before electrodes and MRI scans, all we knew about the brain was how it is put together.
All this has made the brain a unique thing in our history. Like ancient voyagers we mapped and charted it long before we knew what any of its parts actually did. Because of this, the brain is full of wonderful and tantalising names, like the mysterious continents at the periphery of some medieval map – ‘here be monsters’. There are seahorses, wedding chambers, almonds, underpants, hillocks and little patches of sky in your brain, and you probably never even knew.
This book is a grand tour of the geography of your brain – its roads, rivers, and communities. And by the end you will realise that knowing how that convoluted mass inside your skull is put together is the best way to understand how it works.
Oh, and by the way, the image for part 3, below, is of me.
Part 1: A GRAND TOUR OF TERRA INCOGNITA
The Spinal Cord: Sailing from the Horse’s Tail to the Mysterious Obex
The story starts with the first recorded human speculations about the brain, dating from an eerie ancient Egyptian text probably written by Imphotep, designer of the Step Pyramid. Although his first look at the brain was tentative, he clearly realised that it did something very exciting. As the centuries passed, knowledge and understanding grew, and by the time of the Greeks and Romans, many philosophers suspected that that brain was the prime perceiver of the senses, and prime mover of the body. The realisation that this soft, friable mass, imprisoned in its bony box, is the place where we all actually are has become one of the central tenets of modern thinking. Studying the brain is a unique process: can a structure like a brain ever understand itself? Once the brain’s central place in the affairs of the body is established, I go on to explain how for almost all the time we have studied the brain, all we knew about it was its exuberantly complex structure – and because of this, most of the parts of the brain now carry fanciful and evocative names which bear no relevance to their function. Despite this, I argue that the structure of the brain is not nearly as complicated as it may seem at first sight: there are themes and trends which help to make structure the simplest way to understand the brain. This is why, by the end of this book, you will truly understand how the brain works.
Part 2: AN ASSAULT ON THE SENSES
The Brain Stem: Plunging from the Zonules of Zinn into the Inner Labyrinth
Very early, natural scientists knew that studying the senses is an excellent way of studying the brain. And after Darwin, biologists have realised that the structure of the modern human brain can be explained in terms of the simultaneous evolution of our mental faculties and the sense organs with which we perceive the world. And the brain stem is where senses and evolution meet. There is a wonderful story here, dating back to the first mud-grubbing creatures who ever tried to hear, see or smell the environment around them. All backboned animals share the basic layout of our brain, yet they adapt its basic elements to suit their lifestyles … and the story ends with the immensity of human intellect. I use this approach to answer such questions as why smells evoke déjà vu, what makes us fall asleep, why our eyes are wired up backwards, why dolphins sing chords, and why some people think other people’s names have distinctive smells. The brain stem is the centre of our existence – keeping us alive, firing our visceral lusts, connecting our skull-imprisoned selves to the world outside. Buttocks, blindsight and black stuff – the brain stem has it all.
Part 3: WHERE ALL THE MIND MAY BE FOUND?
The Cortex: Soaring above the Islands of Calleja and the Radiations of Zuckerkandl
The cerebral cortex is the iconic image of the human brain – two huge corrugated hemispheres which epitomise the intellectual superiority of our species. Or do they? All backboned animals have this part of the brain, and in some of them it bigger and more convoluted than ours. The human brain has no unique, distinctive anatomical structure denied to other animals. So where is the uniqueness of the human mind? The third part of the book looks at how we have studied the writhing cortex – from the early experiments, electrically stimulating the living cortex in conscious humans, to cutting edge molecular dissection of the essence of fear, learning and memory. Although much of what we think of as distinctively human is up here in the cortex, in some ways this part of the brain is nothing more than an overblown smell-interpreting centre. Maybe all that separates us from the beasts is the sheer size of our cortex, and the strain this has put on the evolution of the human race. At the end of the book, having mustered fifty centuries of understanding of the brain, I take the opportunity to tackle the nature of consciousness: whether it can ever be defined, how it is engineered into our three-pound minds, where it came from. I also discuss what it will be like when your consciousness switches off – as you die.
Reviews and comments
Publication of Zonules led to the following:
Radio Interviews: To the Best of Our Knowledge (USA, nationally syndicated, 23 Feb 09).
Television appearances: Bettany Hugh’s Ancient World: Alexandria (More4).
Reviews and comments
The book was selected to be in The Booklist Online’s Top 10 Science Books 2008, and the Confessions of a Science Librarian blog’s Best Science Books 2008 Booklist:
Absorbing...[Bainbridge's] witty journey from spinal cord through brain stem to cerebral cortex, ending with a cautious chapter on the "deceitful spectre" of consciousness, is unashamedly personal...Despite the complexity of the human brain, Bainbridge seeks to convince the non-specialist that it is, in fact, "simpler than you might have thought."...Highly informative and historically minded.
Andrew Robinson, The Lancet
‘Engaglingly vivid’: The success and joy of David Bainbridge's book is to make such unusual names a spur to interest. His explanations also benefit from his knowledge of development and his ability to make cross-species comparisons. … This book does an excellent job of introducing the layout of the brain in an easily digestible form through describing the history of its discovery while celebrating quirkiness in its nomenclature and the eccentricities of early anatomists. … Bainbridge has an accessible style and a vivid turn of phrase. … This book is enjoyable to read and provides an excellent contribution to making some of the apparently bizarre structure and functioning of the brain accessible to the lay reader.
M. W. Brown, Times Higher Education Supplement
On the evolutionary trail, he describes how primitive drives (such as hunger, sex and sleep) evolved into higher functions, including memory, learning and emotions. Gender differences, brain size, intelligence and even bizarre teenage behavior all have underpinnings in neural anatomy. Bainbridge marvels at how the fragile sheet of the cerebral cortex organizes our sensations, leading naturally to consciousness. In contrast to philosophical speculations on consciousness, Bainbridge focuses on neural hardware. Distilling seven leading theories of consciousness, he argues that consciousness is material, not mystical—something “our brain does.”
He also injects … humor into the narrative flow, which he makes so intelligible as well as absorbing that perhaps his next book should be a primer for popular-science writers.
Ray Olson, ilovelibraries.org
David Bainbridge is establishing a reputation for clear, popular science writing, laced with imaginative flair and good humour, plus the essential skill of good story-telling. It is a reputation this book is likely to enhance.
Human Givens Journal
Isaac Asimov's nonfiction writing on science was famously marked by a seemingly effortless clarity amid complex ideas, a personal passion and experience, and a general infectious glee in the marvels of the cosmos. The same qualities shine through in David Bainbridge's Beyond the Zonules of Zinn. Vibrantly communicating his own sense of wonder at the intricacies of the human brain, the author handily escorts the reader through an anatomical and evolutionary labyrinth… The chapters on vision are typical of Bainbridge's ability to parse the intricate machinery of nerves and neurons, lenses and retinas, but perhaps his most endearing trait is the juvenile delight he takes in the various gruesome abnormalities and diseases of the mind.
Paul DiFilippo, Barnes & Noble Review
The book's relaxed pace, interesting tangents and broad coverage make this book eminently suitable for anyone curious about the brain.
In this wonderful exploration of the brain … Writing in prose that is precise, descriptive, and engaging, he offers vibrant depictions of neuroscientists’ discoveries and the brain’s evolution.
Candice Kai, starred review, Library Journal
In Beyond the Zonules of Zinn, David Bainbridge takes readers on an entertaining and engaging tour of the human brain and nervous system. A clinical anatomist at England’s Cambridge University, Bainbridge explains how early scientists tried to describe almost every crease and canal of the brain with strange and fantastical names before they had any idea of what the various structures actually did.
In all, I can find really no fault in this book… Instead of merely presenting the anatomy, its histology, and function, as you could find in so many neuroanatomy texts, he places all of this knowledge in light of what was known, or thought to be know, throughout history. In all of this he doesn’t assume any level of knowledge, and explains all that is needed to continue the journey… It really is quite beautiful, evolution, and being shown by a veterinarian where we fit in the story of life makes the development of the story that much more amazing.
Beyond The Zonules of Zinn made me laugh and parts of it were so - well, I'll just say it the way I said it to my daughter and her father when I insisted on reading parts of it aloud to them - "...f---king incredible, I can't explain it, you have to let me read this to you!".
A wonderfully accessible book of brain function and structure.
M. Vasudeva, Amazon.com
It was structured as a trip - an exceedingly fantastic voyage - up the spinal cord and into the brain, discussing the extraordinary features which occur seemingly at every millimeter along the way. … I am penning this short article because it not only lived up to expectations, but surpassed them in terms of wit, humour, graceful writing, and, above all, interest and knowledge. I urge all who are inquisitive readers, to buy the book.
Dick Jenssen, Amazon.com
See also: Ginger Campbells’ Brain Science Podcast #32 at: www.brainsciencepodcast.com