Wednesday's TV Highlights: Alan Alda has his head examined on 'The Human Spark'
GRAY MATTER: 'The Human Spark' uses high-tech imaging techniques provide a glimpse inside the head of host Alan Alda at 8 p.m. on KCET. wnet.org / PBS
The New Adventures of Old Christine: Christine's (Julia Louis-Dreyfus) promising romance with her therapist-boyfriend (Eric McCormack) threatens to be derailed by her old flame (Blair Underwood). Clark Gregg and Hamish Linklater also star (8 p.m. CBS).
Mercy: A newlywed cancer patient undergoes a risky course of treatment, and after a man wakes up from 10 years in a coma he decides to confront the woman he loves (8 p.m. NBC).
American Idol: Auditions continue in Orlando, Fla., with Kristin Chenoweth as a guest judge (8 p.m. Fox).
Gary Unmarried: Gary (Jay Mohr) faces a tough decision after he and his girlfriend and boss (Brooke D'Orsay) take their relationship to the next level, forcing him to fret over whether it's a wise move to put his dream job on the line for the sake of a relationship that may not pan out (8:30 p.m. CBS).
Criminal Minds: A rash of teen suicides in a small Wyoming town draws the focus of Rossi and Hotchner (Joe Mantegna, Thomas Gibson) and the rest of the BAU team, who wonder whether the deaths may be linked by the Internet. Paget Brewster, Shemar Moore and Matthew Gray Gubler also star (9 p.m. CBS).
Modern Family: Mitchell (Jesse Tyler Ferguson) plants an idea in Jay's (Ed O'Neill) head that one of his old buddies (Chazz Palminteri) may be gay, which leads to Jay noticing a bunch of "signs" for the first time (9 p.m. ABC).
Human Target: Winston and Chance try to protect a client they have never met from an assassin on a passenger plane in this new episode (9 p.m. Fox).
Great Performances at the Met: The episode "The Audition" takes viewers behind the scenes at the Metropolitan Opera's National Council Auditions (9 p.m. KCET).
Ghost Hunters International: The team travels to Australia, to investigate the Quarantine Station, imagined to be Australia's most haunted area (9 p.m. SyFy).
Dog the Bounty Hunter: Dog and his team are pursuing a fugitive who has a short fuse and could react violently to being caught. Dog does his best to prepare his people for anything, but they still wind up being surprised in this new episode (9:30 p.m. A&E).
Toddlers & Tiaras: This new episode heads to Florida for the Little Miss Glitz pageant (10 p.m. TLC).
Baby Boy: Tyrese Gibson plays a young man who has a hard time meeting his responsibilities as a father, which his background hasn't prepared him for. Ving Rhames, Omar Gooding and Snoop Dogg also star in director John Singleton's 2002 drama (7:45 p.m. Cinemax).
College basketball: Wake Forest at North Carolina (4 p.m. ESPN); South Florida at Cincinnati (4 p.m. ESPN2); Baylor at Kansas (6 p.m. ESPN2).
Pro basketball: The Utah Jazz visit the San Antonio Spurs (6 p.m. ESPN); the Chicago Bulls visit the Clippers (7:30 p.m. FS Prime).
Tennis: Australian Open, second round, from Melbourne, Australia (8 p.m. and midnight ESPN2).
Photo: wnet.org / PBS