(David Duprey/AP)

“This is a story of a family who made mistakes.” Thus Janet Sternburg begins her memoir of a close-knit Jewish family living in Boston.

Her grandfather, Philip, was a cold, angry man who abandoned his wife and six children not long after the only son in the family, Bennie, was diagnosed as schizophrenic. As Bennie became increasingly violent and untreatable, the family — advised by a Harvard professor of psychiatry — agreed to submit him to a prefrontal lobotomy. More than a decade later, one of Bennie’s sisters, Francie, sank into a debilitating depression — relentlessly weeping, attempting suicide — and again, the solution was seen to be a lobotomy.

While she was growing up, Sternburg accepted the lobotomies as her family’s normalcy. It was decades later, when she was an adult living in California, that it occurred to her to question why such terrible measures had been taken.

“The years came back to me when my aunt and uncle were driven to our house” for a regular visit, she writes. As the grandmother cooked and the aunts and uncles talked and played cards, the two lobotomized siblings “sat blankly on the couch — Bennie at one end, virtually unmoving, my aunt crumpled into the far corner. . . . With the sharp return of memories came the realization that even as a child I had a slight awareness . . . that something wrong had been done.” But she also knew her relatives as good and generous people. So she set out to learn what happened, and why.

White Matter: A Memoir of Family and Medicine” is Sternburg’s tale of what she discovered, put in the context of her family’s history, the currents of 20th-century psychiatry, the fallibilities of the medical profession and the painful decisions that many of us make. And while lobotomization is now a discredited procedure, her discoveries were somewhat complicated: “When I began this investigation, I assumed that lobotomies produced only zombie-like people. But I’ve learned since that they sometimes provided genuine relief to people who, to my surprise, were able to . . . say how much better they were.”