Veteran television reporter and producer Robert Krulwich lends his intelligent and accessible manner to “Nova ScienceNOW” (7 p.m., PBS), a new series dedicated to exploring and popularizing the latest scientific theories and discoveries.

“ScienceNOW” kicks off with a provocative discussion of the notion of the “mirror neuron system.” While experimenting with monkeys, an Italian scientist learned that a particular brain neuron fired every time his subject reached for a peanut. He then observed that the same neuron also fired when the monkey merely watched a lab assistant reaching for the peanut. For that very specific part of the brain — now called the mirror neuron — “doing” and “watching” were the very same thing.

Scientists now theorize that this mirror neuron explains the ability of higher primates to learn while observing and for humans to “experience” emotions while simply taking in a tear-jerking movie or exciting football game.

Others see the ability to learn, empathize and “experience” while merely watching to be a key development in human evolution. As somebody who has to watch an awful lot of television, I began to worry about what I’m putting my mirror neurons through.

“ScienceNOW” will appear in the regular “Nova” timeslot five times throughout the year.

• Auditions continue on “American Idol” (7 p.m., Fox). This talent showcase returned last week and immediately re-asserted itself as America’s favorite network show. As expected, the audition process offered an often-amusing mix of genuinely talented and downright delusional contestants. But there were moments last week when the spirit of the proceedings turned toward the cruel and mean-spirited.

It’s one thing to laugh at the tone-deaf, it’s quite another to joke about clearly unstable participants. And Ryan Seacrest crossed a line when he repeatedly joked about singers “hearing voices” and having multiple personalities. I hate to sound like a humorless scold, but schizophrenia is a cruel reality for many of our neighbors and loved ones. It’s no joke. A show as popular and family-oriented as “Idol” shouldn’t encourage people to belittle the mentally challenged.

• Dave Foley is host to a new season of “Celebrity Poker Showdown” (7 p.m., Bravo), featuring guests Brad Garrett, Catherine O’Hara, Ray Romano, Sara Rue and Curt Schilling. What’s wrong with this picture? For all of the chuckles and banter, this is still a show about popularizing gambling, and Schilling is a professional athlete. Famous jocks, including Pete Rose, Joe Namath, Willie Mays and Mickey Mantle, have been chastised and worse for consorting with gamblers. Schilling shouldn’t touch this with a 10-foot-pole.
• “Queer Eye for the Straight Guy” (9 p.m., Bravo) jets off to London to save a musical relic from the 1980s from his own dated taste and deplorable hygiene. Graham Norton cameos.
• “Snap!: A history of the Paparazzi” (7 p.m., Discovery Times) looks at the evolution of intrusive celebrity photography, from “La Dolce Vita” to today.

Tonight’s other highlights

• Carmen Electra plays host to “AutoRox” (8 p.m., Spike), the first television awards show for cars. Kid Rock is among the musical guests featured.
• An act of compassion is misconstrued on “Gilmore Girls” (7 p.m., WB).
• A race against the clock for toxic teens on “House” (8 p.m., Fox).
• “Frontline” (8 p.m., KTWU; 9 p.m., KCPT) looks at Al Qaeda’s growing presence in Europe.
• An essay proves revealing on “Judging Amy” (9 p.m., CBS).
• New leads emerge about a long-missing boy on “Law & Order: Special Victims Unit” (9 p.m., NBC).
• A blueblood is bloodied on a drug-infested block on “NYPD Blue” (9 p.m., ABC).
• “Real Sports with Bryant Gumbel” (9 p.m., HBO) profiles Joe Buck.

Series notes

An excavation yields a corpse in a bridal gown on “Navy NCIS” (7 p.m., CBS) … Gaffes abound on “Most Outrageous Moments on Live TV 2” (7 p.m., NBC) … Michael proves distracting on “My Wife and Kids” (7 p.m., ABC) … Sparks fly at dinner on “All of Us” (7 p.m., UPN).

And nothing but the tooth on “George Lopez” (7:30 p.m., ABC) … Very physical therapy on “Eve” (7:30 p.m., UPN).

Competitive globetrotting on “The Amazing Race” (8 p.m., CBS) … A lesson in carpe diem on “Scrubs” (8 p.m., NBC) … A lesson in jealousy on “According to Jim” (8 p.m., ABC) … A missing father on “Veronica Mars” (8 p.m., UPN) … Big secrets on “One Tree Hill” (8 p.m., WB).

A reluctant gift-giver on “Committed” (8:30 p.m., NBC) … Charlie needs company on “Rodney” (8:30 p.m., ABC).

Late night

Hilary Swank, Andy Dick and Green Day appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno hosts Dennis Miller and Brian McKnight on “The Tonight Show” (10:35 p.m., NBC).

Paris Hilton, Stuart Townsend and Scissor Sisters are booked on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Craig Ferguson hosts Joe Montana, Famke Janssen and Richard Jeni on “The Late, Late Show” (11:37 p.m., CBS).