The world inside the head

There’s a widespread belief that biology can best be understood at the level of molecular interaction. Although the website of the UK Medical Research Council (MRC) proclaims that it gives a high priority to research that is likely to make a real difference to clinical practice and the health of the population, it spends the lion’s share of its budget on molecular and cellular research. That this is the right thing to do goes virtually unchallenged. Five years ago the House of Commons Science and Technology Committee published a highly critical report of the workings of the MRC, forcing George Radda, then its chief executive, into making the memorable excuse that “with hindsight we should have had more foresight.” But the committee was criticising the way in which the budget was administered rather than how the money was spent.

However, even if we put aside doubts about whether the bodies that fund medical research have achieved the right balance between basic biology and questions relevant to the care of patients, it’s surely a mistake to think that focusing on the minutest levels is the best way to reveal the workings of complicated systems. No economist wanting to make sense of global markets would think the way forward was to study the behaviour of individual shoppers. No one wanting to get to grips with how computers worked would start with the physics of semiconductors. A worm’s eye view doesn’t always provide a useful perspective. Adapting a metaphor invented by the neurobiologist Steven Rose, a visiting Martian wanting to make sense of a page of the BMJ wouldn’t make much progress if it concentrated its efforts on a chemical analysis of the paper and ink.

The human brain is a complicated machine, by any standards. Some versions of it (Newton’s, Mozart’s or Einstein’s, for example) can do breathtakingly clever things, but even the standard issue is pretty impressive. Despite the fact that the brain’s remarkable abilities must ultimately reside in the movement of molecules across membranes, it doesn’t follow that by studying these things we shall understand how it works.

Adam Zeman clearly realises this, and the strength of his book is how it ranges from the atomic to the ineffable. He has structured it as a series of different levels, starting at the smallest, a molecule of oxygen, and then increasing in size and complexity through subcellular organelle, nerve cell, neuronal networks, and brain regions. He ends ambitiously with mind and consciousness.

At the same time, each chapter tells the story of a patient: a young woman disabled by feelings of exhaustion, or a middle aged man with a compulsion to collect discarded objects, for example. These stories aren’t case reports in any medical sense. They have little clinical detail and concentrate more on the patients’ subjective feelings than on the features that might help a neurologist arrive at a diagnosis. But the device works well in giving a counterpoint to the neuroscientific explanation. The description of local neural networks, for instance, gains immediacy and relevance by being centred on the stories of two patients who experienced distortions of memory: a young woman with déjà vu and an astronomer who has an episode of transient global amnesia.

Philip Larkin famously thought that sexual intercourse began in 1963, and many biologists have a similar idea—not about sex, of course, but about their subject, which they think began 10 years earlier in 1953 when the structure of DNA was worked out. Zeman doesn’t share this delusion. He knows that the history of the scientific investigation of the nervous system stretches back a long way, and he appreciates the huge conceptual advances made by men such as Santiago Ramón y Cajal and Charles Sherrington in the 19th century and early 20th century. Another strength of the book is the way these earlier contributions are successfully incorporated into an entirely modern, if rather incomplete, account of neuroscience.

As the book unfolds it manages to convey something of the texture of the author’s everyday life as a working clinician. We hear him complaining that the NHS doesn’t allow him enough time for each patient; at the end of a clinic he is getting tired and looking forward to a holiday; he beats himself up over a missed diagnosis. It’s not exactly warts and all, but it feels honest and uncontrived. His enthusiasm for neurology and his fascination with the workings of the nervous system come across clearly.

It’s really this that makes the book worth reading. Rather few books are written about work—and why people do the jobs they have chosen and the effect that it has had on them.