How botulinum toxin affects nonverbal communication: a visualisation using artificial intelligence

The use of botulinum toxin is becoming exceedingly popular (Figure 1), particularly among younger people. Botulinum toxin works against wrinkles by relaxing facial muscles, and it may also profoundly affect facial expressions. Facial expressions are an important part of a person's individuality. They are not only important for feeling emotions and expressing them, but also for interpersonal communication.

The author raised the question: will we still understand one another if we can no longer fully use facial expressions in non-verbal communication?

This question was explored by running a standardised and protocolised routine of 18 facial expressions before and 2 weeks after full facial injections with botulinum toxin (Figure 2). Facial expressions were read out from high-resolution video using (1) facial emotion-reading software (i.e. artificial intelligence) and (2) the human eye (Figure 3).

While the subject made the same effort to express emotions before and after botulinum toxin, the outcomes were clearly different. Depending on the readout (i.e. emotion-reading software or the human eye), clear inabilities to display disgust or a genuine smile (‘Duchenne smile’) were detected after botulinum toxin treatment (Figures 4 and 5). Some discrepancies were noted between the two different readouts, demonstrating the subjective and complex nature of emotions, and, perhaps, the complex nature of the effects of botulinum toxin thereon.