Oliver Sacks, who died on August 30, was a longstanding contributor of thirty essays to The New York Review of Books. His last published article, below, appears in the Review’s September 24 issue.


Royal Library, Windsor Castle

Detail of a drawing by Leonardo da Vinci, circa 1510–1511

Walter B., an affable, outgoing man of forty-nine, came to see me in 2006. As a teenager, following a head injury, he had developed epileptic seizures—these first took the form of attacks of déjà vu that might occur dozens of times a day. Sometimes he would hear music that no one else could hear. He had no idea what was happening to him and, fearing ridicule or worse, kept his strange experiences to himself.

Finally he consulted a physician who made a diagnosis of temporal lobe epilepsy and started him on a succession of antiepileptic drugs. But his seizures—both grand mal and temporal lobe seizures—became more frequent. After a decade of trying different antiepileptic drugs, Walter consulted another neurologist, an expert in the treatment of “intractable” epilepsy, who suggested a more radical approach—surgery to remove the seizure focus in his right temporal lobe. This helped a little, but a few years later, a second, more extensive operation was needed. The second surgery, along with medication, controlled his seizures more effectively but almost immediately led to some singular problems.

Walter, previously a moderate eater, developed a ravenous appetite. “He started to gain weight,” his wife later told me, “and his pants changed three sizes in six months. His appetite was out of control. He would get up in the middle of the night and eat an entire bag of cookies, or a block of cheese with a large box of crackers.”

“I ate everything in sight,” Walter said. “If you put a car on the table, I would have eaten it.” He became very irritable, too, he told me:

I raged for hours at inappropriate things at home (no socks, no rye bread, perceived criticisms). Driving home from work a driver squeezed me on a merge. I accelerated and cut him off. I rolled my window down, gave him the finger, and began screaming at him, and threw a metal coffee mug and hit his car. He called the police from his cell. I was pulled over and ticketed.

Walter’s attention assumed an all-or-none quality. “I became distracted so easily,” he said, “that I couldn’t get anything started or done.” Yet he was also prone to getting “stuck” in various activities—playing the piano, for example, for eight or nine hours at a time.

Even more disquieting was the development of an insatiable sexual appetite. “He wanted to have sex all the time,” his wife said.

He went from being a very compassionate and warm partner to just going through the motions. He didn’t remember having just been intimate…. He wanted sex constantly after his surgery…at least five or six times a day. He also gave up on foreplay. He would always want to get right to it.

There were only fleeting moments of satiety, and within seconds of orgasm, he wanted intercourse again and again. When his wife became exhausted, he turned to other outlets. Walter had always been a devoted and thoughtful husband, but now his sexual desires, his urges, spread beyond the monogamous heterosexual relationship he had enjoyed with his wife.

It was morally inconceivable for him to force his sexual attentions on a man, woman, or child—Internet pornography, he felt, was the least harmful answer; it could provide some sort of release and satisfaction, even if only in fantasy. He spent hours masturbating in front of his computer screen while his wife slept.

After he started viewing adult pornography, various websites solicited him to purchase and download child pornography, and he did. He became curious, too, about other forms of sexual stimulation—with men, with animals, with fetishes.1 Alarmed and ashamed of these new compulsions, so alien to his previous sexual nature, Walter found himself engaged in a grim struggle for control. He continued to go to work, to go out socially, to meet his friends for meals or movies. During these times he was able to keep his compulsions in check, but at night, alone, he gave in to his urges. Deeply ashamed, he told no one of his predicament, living a double life for more than nine years.

Then the inevitable happened, and federal agents came to Walter’s house to arrest him for possession of child pornography. This was terrifying, but it was also a relief, because he no longer had to hide or dissimulate—he called it “coming out of the shadows.” His secret was exposed now to his wife and his children, and to his physicians, who immediately put him on a combination of drugs that diminished—indeed, virtually abolished—his sexual drive, so that he went from insatiable libido to almost no libido at all. His wife told me that his behavior instantly “reverted back to loving and compassionate.” It was, she said, as if “a faulty switch was turned off”—a switch that had no middle position between on and off.


I saw Walter on several occasions in the time between his arrest and his prosecution, and he expressed fear—mostly of the reactions of his friends, colleagues, and neighbors. (“I thought they would point fingers or throw eggs at me.”) But he thought it unlikely that a court would view his conduct as criminal, in view of his neurological condition.

On this point, Walter was wrong. Fifteen months after his arrest, his case finally came to court, and he was prosecuted for downloading child pornography. The prosecutor insisted that his so-called neurological condition was of no relevance, a red herring. Walter, he argued, was a lifelong pervert, a menace to the public, and should be put away for the maximum term of twenty years.

The neurologist who had originally suggested temporal lobe surgery and had treated Walter for almost twenty years appeared in court as an expert witness, and I submitted a letter to be read in court, explaining the effects of his brain surgery. We both pointed out that Walter’s condition was a rare but well-recognized one called Klüver-Bucy syndrome, which manifests itself as insatiable eating and sexual drive, sometimes combined with irritability and distractibility, all on a purely physiological basis. (The syndrome had first been recognized in the 1880s, in lobectomized monkeys, and subsequently described in human beings.)

The all-or-none reactions that Walter had shown were characteristic of impaired central control systems; they may occur, for example, in parkinsonian patients on L-dopa.2 Normal control systems have a middle ground and respond in a modulated fashion, but Walter’s appetitive systems were continually on “go”—there was scarcely any sense of consummation, only the drive for more and more. Once his physicians became aware of the problem, medication readily brought it under control—albeit at the cost of a sort of chemical castration.

In court, his neurologist emphasized that Walter was no longer subject to his sexual urges, and that he had never actually laid hands on anyone other than his wife. (He also noted that, among more than thirty-five cases on record of pedophilia associated with neurological disorders, only two had been arrested and charged with criminal behavior.) In my own letter to the court, I wrote:

Mr. B. is a man of superior intelligence and a real moral delicacy and sensibility, who at one point was driven to act out of character under the spur of an irresistible physiological compulsion…. He is strictly monogamous…. There is nothing in his history or his current ideation to suggest that [he] is a pedophile. He poses no risk to children or to anyone else.

At the end of the trial, the judge agreed that Walter could not be held accountable for having Klüver-Bucy syndrome. But he was culpable, she said, for not speaking sooner about the problem to his doctors, who could have helped, and for persisting for many years in behavior that, by supporting a criminal industry, was injurious to others; “yours is not a victimless crime,” she emphasized.

She sentenced him to twenty-six months in prison, followed by twenty-five months of home confinement and then a further five-year period of supervision. Walter accepted his sentence with a remarkable degree of equanimity. He managed to survive prison life with relatively little trauma and made good use of his time in jail, establishing a musical band with some fellow inmates, reading voraciously, and writing long letters (he often wrote to me about the neuroscience books he was reading).

His seizures and his Klüver-Bucy syndrome remained well controlled by medication, and his wife stood by him throughout his years of prison and home confinement. Now that he is a free man, they have largely resumed their previous lives. They still go to the church where they were married many years ago, and he is active in his community.

When I saw him recently, he was clearly enjoying life, relieved that he had no more secrets to hide. He radiated an ease I had never seen in him before.

“I’m in a real good place,” he said.