Book review: The three-pound enigma

The Three-Pound Enigma: The Human Brain and the Quest to Unlock Its Mysteries, by Shannon Moffett. Algonquin Books of Chapel Hill, 2006.

This overview of the current state of brain science is both entertaining and informative. Each chapter covers a particular facet of the sprawling field: neurosurgery, cognitive neuroscience, neuroethics (itself a multi-faceted field), sleep and dream studies, etc. Moffett, a medical student at Stanford, hung out with some of the top researchers and thinkers in neuroscience, which gives the book the feeling of a series of good conversations with curious minds (e.g., Christof Koch and Francis Crick on the search for the neural correlates of consciousness, John Gabrieli on memory, Daniel Dennett on the nature of consciousness). The book is also filled with interesting tidbits of information, like why you shouldn’t go into an fMRI machine if you’ve ever worked in a machine shop, how the video game Tetris was used to study dreaming and memory, and the story of how Francis Crick and his wife Odile met. I really enjoyed the feeling that I was getting to know some of the personalities behind the research I read about. And while some of the information was not new to me, I learned a surprising amount about how the brain works and how research on the brain proceeds.

The chapters are interspersed with a series of “interludes”, brief descriptions of the brain at various stages of life, starting at three weeks after conception and ending with death. These were probably the most educational for me, because my knowledge of brain anatomy, and in particular brain development, is far from complete. The one that stands out most in my mind described the chemistry of how synapses fire; it’s one of the longer interludes and took a little effort to follow. The payoff came at the end:

The significance of the foregoing, and the reason to have waded through it at all, is that–as Francis Crick pointed out–as far as we can tell, every thought (wondering what you’ll have for lunch or what you’ll wear tomorrow), every desire (for glory, for that hottie you see at the gym, for a peanut-butter sandwich), and every experience (of reading this book, for instance–of your hand on the page, the quality of the light you are reading by, the feeilng of your breathing) that you have or have ever had is nothing but the opening and closing of those ion channels and the release and uptake of those neurotransmitter molecules. One of the great philosophic questions forced upon us today is how that knowledge could or shoudl change our concept of what it means to be human.

Now, I have long believed that we have no immaterial souls, no consciousness beyond what arises out of the activity between our ears, so this is not exactly news to me, but somehow reading the detailed description of how it works at the level of the calcium and potassium channels really brought home to me how wonderful a thing it is that from such small chemical events such a rich variety of experiences can arise.

The interludes were integrated well into the rest of the content; the last one in particular, about brain death and the difficulties that sometimes arise in determining when it has occurred, fits in very neatly after a chapter on neuroethics. And overall I thought there was a good balance between the parts about brain anatomy and physiology, the discussions of what consciousness is and how we can learn about it, and the explorations of human behavior and experience. If you are squeamish and if, as I do, you read while you eat, be aware that the book opens with a description of an autopsy and the first chapter is about brain surgery. The brain surgery chapter in particular, interesting as it was, gave me a mild case of the heebie-jeebies; I really don’t like to think about how vulnerable the brain is and how many things can go wrong with it.

In a number of places Moffett refers to her web site,, which has links to demos of some of the things she describes. (Follow the “Web content” link. Given the fluidity of the web, some of the links no longer work.) Far and away the most entertaining was the link to a video made by Daniel Simons that illustrates the limits of our attention to our surroundings. (Go to The video shows people in white shirts and people in black shirts passing basketballs around; it’s a bit of a crowded scene, but when you watch the video, do your best to focus on the passes from one white-shirted player to another white-shirted player and count them. Then watch the video again without focusing on anything in particular. Anything else I could say would be a spoiler.)