How can the vagus nerve enhance our ability to recognize emotions?
For the first time, as suggested by Charles Darwin and Stephen Porges, my colleague Roberta Sellaro and I proved that the vagus nerve (X cranial nerve) is involved in reading the emotions of others.
In a nutshell, our results are based on the idea that mammals are the only vertebrates that possess a myelinated vagus and that optimal social interaction, which includes the recognition of emotion in faces, is modulated by the vagus nerve. To stimulate the vagus nerve we used a novel non-invasive technique called transcutaneous (through the skin) vagus nerve stimulation. When the vagus nerve was stimulated compared when it was not (sham stimulation), people were better at recognizing other’s emotions in a task that requires participants to assess someone’s emotions based on images of the eye region (“Reading the Mind in the Eyes” test).
Our results are not only interesting for healthy people but they may be exciting from a clinical point of view as well, given that people suffering from depression and autism (conditions in which the vagus nerve is not working properly) have trouble in reading the emotions of others. Enhancing the ability to decode the affective mental state of others might be helpful for people suffering from these pathologies by diminishing social ambiguity and promoting social communication.
Colzato, L. S., Sellaro, R., & Beste, C. (2017). Darwin revisited: The vagus nerve is a causal element in controlling recognition of other's emotions. Cortex, 92, 95-102.