Amy Ellis Nutt is a science writer at The Washington Post where her beat is the brain.

Breakthroughs in our understanding of the human brain have often come at the expense of patients: Psychology students continue to learn about the origins of memory from the case of H.M. In 1953, surgeons relieved Henry Molaison of his epileptic seizures by removing part of his brain. At the same time, however, they unwittingly rendered him amnesic. Molaison’s loss was science’s gain: We now know the hippocampus is where memories are processed.

John Elder Robison wasn’t the victim of a surgical mistake, but there was a gap in his life of which he was keenly aware and which made social relationships, even encounters with strangers, monumentally challenging. He was awkward, couldn’t read physical cues in other people and was emotionally detached during even the most stressful situations. In one incident from years earlier, he relates how he was driving late at night when he encountered a scene in the middle of a deserted road: a man’s legs sticking out from under a car. One of the front tires lay on its side, next to a rusty old bumper jack that had clearly broken or been dislodged. The man was obviously crushed to death, and six feet away his friend sat cross-legged, rocking back and forth, in shock. Robison asked the man, “What’s going on?” No answer. He repeated the question. Still no answer. Eventually he decided to walk down the road and knock on a door. “Call the cops. . . . There’s a wreck out there, and someone’s dead,” he said to the first one who answered. When the door closed in his face, Robison returned to the scene of the accident, said nothing more to the man rocking beside his dead friend, then sat in his car and waited for the police. To anyone his behavior would have seemed bizarre and surreal, but as Robison writes, “Being emotionally blind isn’t the same thing as being uncaring or amoral. . . . It’s just that my senses and abilities were limited, so I didn’t always do what they expected.”

In his first memoir, “Look Me in the Eye: My Life With Asperger’s” (2007), readers learned that this blind spot (as well as Robison’s gift for all things engineering) was probably related to being on the autism spectrum. Robison’s famous sibling, author Augusten Burroughs, who first wrote about their family in his own best-selling memoir, “Running With Scissors,” once humorously described his older brother as having “the emotions of an IBM laptop computer.”

In his astonishing, brave new book, “Switched On,” Robison’s yearning for completeness leads him to volunteer for a scientific experiment that aims to change his brain for the better. After giving a talk about his first book, Robison is approached by a postgraduate fellow in the lab of Harvard neuroscientist Alvaro Pascual-Leone. She tells him about a new clinical trial Pascual-Leone is about to launch at Boston’s Beth Israel Deaconess Medical Center.

"Switched On: A Memoir of Brain Change and Emotional Awakening" by John Elder Robison (Spiegel & Grau)

One theory of autism is that there is an imbalance in the brain’s connections, making some mental tasks confusing and difficult, and others enormously easy. For Robison those easy tasks have involved using his astounding engineering skills to design and run sound systems for rock bands in the 1970s and ’80s (he built the fire-breathing, rocket-launching guitars famously used by KISS). Later, he built electronic toys and games for Milton Bradley and eventually power systems for a laser manufacturer. Most recently, he has restored high-end foreign automobiles. Far more challenging tasks for him: reading other people and understanding their state of mind.

Pascual-Leone wanted to test whether trans­cranial magnetic stimulation, a tool occasionally used to treat depression, could rebalance the brain circuits in individuals with Asperger’s, allowing them to better read people.

Beginning in 2008 and extending over several years, Robison underwent 20 TMS sessions at Beth Israel, hoping the machine’s focused pulses of magnetic energy would give him the ability to do just that. Although 17 of those sessions seemed to alter nothing, three were transformative, resulting in a nearly euphoric awakening.

In prose that is sometimes workmanlike but always clear and precise, “Switched On” details Robison’s discovery of his rich new emotional life. At one point, as he drives home after a session, listening to music from his iPod, he is transported into the past. “All of a sudden, I wasn’t in my car. I wasn’t even in my body. All my senses had gone back in time, and I stood backstage listening to the Tavares brothers singing soul music in a dark, smoky club.” More than a sharpened acuity of his senses is at play, he writes. “Now the experience was richer and deeper, with an added layer of feeling.”

For Robison, it is the beginning of a breathtaking discovery of an emotional dimension that had been missing in his life, and a hunger for more. He hears the smile in someone’s voice, sees sadness in a stranger’s eyes and is taken aback by the mocking tone in a friend’s joke. Aspects of daily living most people never pay attention to are suddenly revelatory. Even his own voice, he writes, “became more expressive, with more tonal change and more change in rhythm or prosody.” At the garage where he restores cars, he writes about “a greater sense of comfort and feeling of connectedness, especially when customers started to describe problems with their cars.” It’s an extraordinary transformation. “I found myself sympathizing with our clients and asking how they felt — with no prompting.”

Robison is exhilarated but chastened. The downside of being better connected to others is recognizing the limitations of those relationships, especially with his wife, whose chronic mental illness had barely registered with him before his treatments: “The TMS opened me up to receiving the feelings of others, and when I was at home with her, I felt like I was being crushed beneath the weight of her depression.”

“Switched On” reads like a medical thriller and keeps you wondering what will happen next. “TMS took away my emotional innocence,” Robison writes, and the effects, the reader knows, could be myriad. Will the euphoria diminish when the experiment ends? Will Robison’s brain be changed permanently? And can TMS help his autistic son the way it seems to help him? Not all these questions are answered, but that’s okay. Robison, who understands that changes in how he experiences others do not mean he’s no longer autistic, takes readers for a ride through the thorny thickets of neuroscience and leaves us wanting more. He is deft at explaining difficult concepts and doesn’t shy from asking hard questions. This is a truly unusual memoir — both poignant and scientifically important. What TMS means for other autistic individuals remains to be seen. What it meant for Robison, good and bad, was life-changing.

Switched On
A Memoir of Brain Change and Emotional Awakening

By John Elder Robison

Spiegel & Grau. 296 pp. $28