According to media reports, Botox injections are causing many actors to lose leading parts in films. Directors, including Martin Scorsese and Baz Luhrumm ("Moulin Rouge"), claim the wrinkle-ridding treatments create faces too “frozen” to express nonverbal emotion.

OK. Admit it. You felt a twinge of nonverbal emotion yourself (schadenfreude, perhaps?) at that news.

But, as the L.A. Times reported Monday, having wrinkles smoothed out by Botox (botulinum toxin type A, to be more precise) may make it more difficult to not only show emotion, but also to comprehend the emotional cues of others.

“Not only do our facial expressions reflect our emotional ups and downs,” writes psychologist and science reporter Siri Carpenter, “they appear to send crucial feedback to our brain …. Without that full feedback loop, our ability to understand — and be understood — might be constrained.”

Carpenter reports on a new study soon to be published in the journal Psychological Science. For the study, Arizona State University psychologist Arthur Glenberg and his colleagues asked 40 women about to undergo Botox treatments to read and respond to (by pressing a key) a series of 60 sentences on a computer. The women repeated the test two weeks later (when the temporarily paralyzing effect of Botox on the corrugator “frown” muscle of the forehead would be at its peak).

“After treatment,” writes Carpenter, “participants were slower to understand sentences conveying sadness or anger than they had been before treatment. There was no such change for happy sentences.”

The post-Botox delay in responding to the sentences was very slight — about one-tenth of a second, on average — but, says Carpenter, “such effects can snowball when communicating with others. ... Let’s say that, in a marital disagreement, your spouse is repeatedly just a tenth of a second too slow in responding, leaving the mounting impression of disinterest or failure to comprehend. If such delays were chronic,  Glenberg says, ‘That’s enough time for a person to get really pissed off.’”

The power of mimicking
This study adds support to the increasingly popular “embodied” theory of cognition — “that aspects of higher thought, such as language, judgment and memory, are shaped by our bodily sensations and movement,” reports Carpenter. She describes other research that shows how simply mimicking an emotional expression (like smiling) can trigger a matching emotional response (like happiness).

You can try this at home: Hold a pen in your mouth, between your teeth. Now hold it between your lips.

“In studies using this pen-in-mouth procedure,” writes Carpenter, “… people actually feel happier and respond more positively to stimuli such as cartoons when they hold a pen between their teeth [which forces a smile] than when they hold it between their lips, which forces a frown.”

Of course, the pen-between-the-teeth-makes-you-happier thing won't work until the Botox wears off.