Yoga unites body and mind, and while she led meditations and could do a headstand, Lee's lifelong negative body image plagued her.

NPR: Review: Om Is Where The Heart Is

And no body language coach would miss the often-tweeted-upon expression that Romney needs to be aware is his biggest negative body language signal.

FORBES: What Their Body Language Coaches Are Telling the Presidential Candidates

"It's painfully obvious that girls' negative body image can come directly from seeing their moms look critically in the mirror and complain, " says Berman.

CNN: Is it harder to raise boys or girls?

Djokovic exhibited more negative body language after Berdych held serve at 5-5, staring up at his coach in apparent disbelief, but the Serb quickly refocused, sending down some solid serves to take the set to a tie-break.

BBC: Novak Djokovic makes short work of Berdych in Melbourne

Over time, she's able to push out negative thoughts about her body and let in supportive ones.

NPR: Review: Om Is Where The Heart Is

John Coplans, on the other hand, chose Type 55 film (which yields a black-and-white positive and negative) in the 1980s to record his own stolid nude body in interlocking blocks of hairy flesh, self-portraits that owe something to Henry Moore and Philip Guston.

WSJ: The Polaroid SX-70 as Sexy Tech | Frances Lehman Loeb Art Center | By Richard B. Woodward

And the tests used to diagnosis hepatitis and HIV are based on the body's immune system response to infection, so some results could have come back negative prematurely.

CNN: Dozens of Okla. dentist's patients positive for hepatitis

Those waves reflect off the body to transmit a three-dimensional image of the passenger that looks like a fuzzy photo negative.

CNN: TSA trying new airline passenger screening machines