Botulin injections in the facial muscles, which relax expression lines and make one’s skin appear younger as a result of a mild paralysis, have another, not easily predictable effect: they undermine the ability to understand the facial expressions of other people. This consequence, as SISSA scientists explain in a new study, depends on a temporary block of proprioceptive feedback, a process that helps us understand other people’s emotions by reproducing them on our own bodies.
By now we are all used to seeing its more or less successful results on celebrities and other individuals. Botox is an aesthetic treatment that exploit the effects of type A botulin toxin. The market for these proceedures is constantly growning. In Italia in 2014 alone, over 250,000 Botox procedures were performed. As such, it is only natural to wonder about the possible side effects of this cosmetic enhancement.
One fairly unpredictable consequence concerns the emotional domain, and in particular the perception of emotional information and facial expressions. “The thankfully temporary paralysis of facial muscles that this toxin causes impairs our ability to capture the meaning of other people’s facial expressions”, explains Jenny Baumeister, research scientist at the International School for Advanced Studies (SISSA) in Trieste and first author of a study just published in the journal Toxicon.
Baumeister’s intuition stems from a very well-known scientific theory, called embodiment. The idea is that the processing of emotional information, such as facial expressions, in part involves reproducing the same emotions on our own bodies. In other words, when we observe a smile, our face too tends to smile (often in an imperceptible and automatic fashion) as we try to make sense of that expression. However, if our facial muscles are paralyzed by Botox, then the process of understanding someone else’s emotion expression may turn out to be more difficult.
Jenny Baumeister had a sample of subjects carrying out a series of different tests assessing their understanding of emotions, immediately before and two weeks after they had had a Botox-based aesthetic procedure, and compared the measurement with a similar sample of subjects that had no treatment. Regardless of the types of measurement (judgement or reaction times) the effect of the paralysis was obvious.
“The negative effect is very clear when the expressions observed are subtle. Instead when the smile is wide and overt, the subjects were still able to recognize it, even if they’ve had the treatment”, explains Francesco Foroni, SISSA researcher who coordinated the study. “For very intense stimuli, although there was a definite tendency to perform worse, the difference was not significant. On the other hand, for “equivocal” stimuli that are more difficult to pick up, the effect of the paralysis was very strong”.
The finding confirms the assumption that, to some extent at least, “embodied” processes help us understand emotions. It also suggests that the negative influence of Botox may be manifest precisely in those situations in which this help could prove most useful.
For instance, think of a normal conversation between two individuals, where mutual understanding is vital to ensure proper social interaction: failure to pick up on emotional nuances or sudden changes in the other person’s mood can make the difference between successful communication and communication breakdown.
“Our study was devised to investigate embodied cognition. At the same time, we think that awareness of this consequence will be of use to those involved in aesthetic medicine, not least to adequately inform people seeking to undergo these treatments” commented Foroni.
Funding: Funding data not available.
Source: Federica Sgorbissa – SISSA
Image Source: The image is adapted from the SISSA press release.
Original Research: Abstract for “Deeper than skin deep – The effect of botulinum toxin-A on emotion processing” by J.-C. Baumeister and G. Papab, F. Foroni in Toxicon. Published online April 26 2016 doi:10.1016/j.toxicon.2016.04.044
Deeper than skin deep – The effect of botulinum toxin-A on emotion processing
The effect of facial botulinum Toxin-A (BTX) injections on the processing of emotional stimuli was investigated. The hypothesis, that BTX would interfere with processing of slightly emotional stimuli and less with very emotional or neutral stimuli, was largely confirmed. BTX-users rated slightly emotional sentences and facial expressions, but not very emotional or neutral ones, as less emotional after the treatment. Furthermore, they became slower at categorizing slightly emotional facial expressions under time pressure.
“Deeper than skin deep – The effect of botulinum toxin-A on emotion processing” by J.-C. Baumeister and G. Papab, F. Foroni in Toxicon. Published online April 26 2016 doi:10.1016/j.toxicon.2016.04.044