How do we understand what other people feel? Somehow, we can ‘read’ the emotions on faces of other people, some easy, some hard. Not all people can understand this nonverbal language. Can we help them improve this ability with a novel brain stimulation?
Autistic persons have problems communicating with others and understanding others’ emotions. For example, they often cannot understand what other people feel by looking at their faces and mimics, which makes the interaction with other people difficult.
Surprisingly, neuroscientists recently discovered that some autism symptoms may be caused by a low activity of the vagus nerve. This so-called ‘wandering’ nerve directly connects the brain with the majority of organs, like heart, stomach and even guts. Scientists found that emotionless face and lifeless speech can be the symptoms that the vagus nerve is not active enough.
So, is there a way to make the vagus nerve work better? Few decades ago, scientists invented a special device, called VNS, which can stimulate the vagus nerve. Initially doctors used it only to treat people with epilepsy, but many studies have shown promising results for different disorders. However, in the past this device had to be implanted, so patients had to undergo a surgery, which could cause side-effects.
Fortunately, a new portable version of this stimulating device, called tVNS, was invented. It looks pretty much like a small headphone and is very handy in everyday life. Recent studies showed that this device has almost the same efficacy as the implanted one, so it can be used for the stimulation. To stimulate the vagus nerve a person just has to put it inside a certain part of his or her left ear. Of course, both ears have the small branch of vagus nerve inside, but studies show that stimulating the right ear can affect heart, which can be dangerous.
Some neuroscientists propose that this portable stimulating device can help patients with autism. In a few experiments, scientists studied how well people can recognize emotions from the photos of somebody’s eyes. They also measured the level of activity of the vagus nerve. They found that people with more active vagus nerve understand the emotions of other people better.
In one very recent study, neuroscientists tested if such stimulation of the vagus nerve can change how healthy people recognize emotions. People had to name the emotions of the eyes while their vagus nerve was stimulated. Indeed, stimulation improved emotion recognition, but only in some images. Results showed that only with easily recognizable emotions stimulation helped, while with the difficult ones stimulation had no effect. This might mean that the vagus nerve indeed modulates how we understand the emotional states of other people, but it is involved in recognizing patterns relevant for the immediate reaction, like fight or flight. At the same time, subtle nuances of social communication are not so vitally important, so they do not demand an immediate response.
In conclusion, recently invented device for the vagus nerve stimulation can increase our ability to recognize the most important social cues and improve how we understand the emotions of other people. This technique can help people with autism to understand the emotions of others better. So, it can help them to lead richer and more comfortable social life.
Winner of the 2017 blog competition for the course Neuromodulation.