No more memories

Patient H.M.: A Story of Memory, Madness, and Family Secrets.By Luke Dittrich.Random House; 440 pages; $28. Chatto & Windus; £18.99.

PATIENT H.M. is probably the most famous human case-study in the history of science. In 1953 he was suffering from severe epilepsy, so he underwent a drastic surgical procedure. The medial temporal lobes, including structures called the hippocampi, were mostly removed on both sides of his brain. The procedure failed to cure him, but it did have unintended consequences. H.M. developed anterograde amnesia: from the age of 27 he never formed a new long-term memory. The moment a thought ceased to be suspended in his consciousness, it was gone. “Every day is alone in itself. Whatever enjoyment I’ve had, and whatever sorrow I’ve had.”

His great loss was an immeasurable gain for science. Studies on H.M. teased apart different types of memory and showed that the hippocampi were required for some of them, demonstrating that there is indeed functional specialisation in specific brain regions. But Mr Dittrich also shows something of the man behind the acronym: Henry Molaison. He dispels the myth that Molaison existed in a sort of nirvana, serenely content in the present. He suffered, and he was manipulated by scientists. In life, his identity was jealously guarded; in death, the dissection of his brain was streamed live on the internet.

Much has been written about H.M., but here Mr Dittrich is uniquely qualified: his grandfather, William Scoville, was the neurosurgeon who operated on him. This book is not simply about H.M., but rather uses him as a springboard to explore the history of neuroscience, from the first records of brain surgery in Egyptian writings to 20th-century psychosurgery and beyond. The story of psychosurgery—operating on the brain to treat mental illnesses—is a dark one, and his grandfather played a key role in it. “None would perform as many lobotomies as [Walter] Freeman,” Mr Dittrich writes of another leading doctor of the time, “who was as prolific as he was passionate. My grandfather, however, would come in a close second.”

Mr Dittrich has honed the narrative to a fine edge by the time his grandfather is standing over H.M.’s brain, scalpel in hand, unable to find the epileptogenic focus, the brain region responsible for the seizures. Most surgeons would simply have sewn him up again. A risk-taker might have removed the temporal lobe from one side of the brain, theoretically giving a 50% chance of removing the focus without removing too much brain tissue. But Scoville did something unexpected—something unjustifiable—in removing both temporal lobes. The personal side of Mr Dittrich’s book wonders why his grandfather did it, and what kind of a man he was. H.M.’s fate is not the book’s only shocking tale. The family secret referred to in the book’s subtitle is foreshadowed early on, but its revelation is no less powerful when it comes.