Season 2 of HBO’s Enlightened finds Laura Dern as fortysomething executive Amy Jellicoe conspiring with an egotistical Los Angeles Times muckraker (Dermot Mulroney) to bring down her corporate overlords. Well-meaning but hopelessly naive — “I’m like the Julian Assange of Riverside,” Amy boasts without a drop of irony — she is quickly in over her head.

“She’s missing so many pieces,” says Dern, 45, shaking her head with weary sympathy. “Poor Amy.”

Decked out in an elegant black cap-sleeved dress at a swanky restaurant off Central Park, Dern is noticeably more sophisticated than her on-screen counterpart. But there are moments when the line between the actress and her creation are less distinct — in the way she gesticulates using her entire torso, hunching her shoulders forward to emphasize a point, or in the passion with which she speaks about the benefits of Transcendental Meditation and the horrors of genetically modified foods.

“What if Lucy became Norma Rae?”

That’s the question Dern used when she pitched Enlightened to HBO, but it’s also an apt summary of her acting style and three-decade career. Conceived while her parents, Diane Ladd and Bruce Dern, were filming Roger Corman’s outlaw biker flick The Wild Angels, Dern claims to have watched the decidedly more wholesome I Love Lucy nearly every day of her life.

Her unique ability to combine these diverse influences — timeless physical comedy meets the risk-taking, socially conscious ethos of 1960s and ‘70s Hollywood — is evident throughout her work, including Alexander Payne’s scathing abortion satire, Citizen Ruth, and now Enlightened, which began its second season on Sunday (9:30 p.m.) and last year won her a Golden Globe.

It’s not surprising that Dern sees her character as a hero, albeit a misguided one. In Season 1, Amy suffers an explosive emotional breakdown at the office, a blandly sinister health-and-beauty conglomerate. She returns from a month in treatment blissed out and determined to change the world — a mission that proves easier said than done.

“The world is changing fast because of noble Amys,” Dern says. “She believes something about herself that I wish for all people, and that is we are all entitled to a voice.”

Co-created by Dern and Mike White, Enlightened premiered in 2011 to positive reviews, but its tricky tone — it’s somehow earnest and cynical at the same time — and a vexing protagonist made it a tough sell for some viewers.

Dern isn’t fazed by the mixed reaction to her character — by now, she takes it as a sign she’s doing something right.

A formative experience was the polarized response to David Lynch’s Wild at Heart, which won the Palme d’Or at Cannes in 1990 and starred Dern, Ladd and Nicolas Cage. “Half the audience is booing at us, screaming, ‘How dare you?’ And half the audience is giving us a standing ovation. And I thought, ‘Oh, I’m making a great movie. This is awesome,’” Dern recalls. “I was raised by folks who trained me well for this terrain.”

Dern’s parents divorced when she was still a baby, and she spent much of her childhood in the care of her “magnificent Alabaman grandmother” while they were off making films with the likes of Hal Ashby and Roman Polanski. During a visit with her mother on the set of Martin Scorsese’s Alice Doesn’t Live Here Anymore, Dern was asked to be an extra, and a star was born.