“Whether this is a benefit or a detriment depends on your goals,” he says.

“For at least some emotions, if you take away some part of the facial expression, you take away some of the emotional experience,” says study researcher Joshua Ian Davis, PhD, a term assistant professor in the department of psychology at Barnard College in New York City.

Botox injections were the No. 1 nonsurgical cosmetic procedure performed in 2009, according to statistics by the American Society for Aesthetic Plastic Surgery .

June 23, 2010 -- Botox injections may do more than smooth your wrinkles and limit your facial expressions. These popular injections may also dampen your ability to feel emotions. The study findings appear in the journal Emotions .

Botox Dampens Emotions

Botox injections smooth wrinkles by paralyzing the underlying muscles that cause the wrinkles. In the new study, participants who received Botox injections self-reported less emotional response to some emotional video clips, and as a result, did not feel their emotions quite as deeply as their counterparts who received treatment with a wrinkle filler called Restylane, which does not paralyze muscles. Instead, Restylane restores volume to facial folds and wrinkles.

This dampened emotional reaction was only related to mildly emotional clips, suggesting that the strength of the emotional impulse may make a difference.

That said, those who received Botox reacted to the same to video clips after their injection as they as they did before they received the injections.

The new research set out to prove the facial feedback hypothesis. This hypothesis suggests that our facial expressions can affect our emotional experience. There seems to be some merit to the hypothesis when the effects of Botox were compared with the effects of Restylane.

More research is needed to validate and expand upon this work, Davis tells WebMD.

“We have not had a chance to specifically isolate each muscle group and determine how they relate to specific emotions," he says. “The kinds of things that would be most interesting to follow up on is to try look more closely at specific emotions and specific muscles such as frown lines, crow’s feet, smile lines.”