Researchers have discovered that the mere sight of someone who appears to be contagious can trigger an immune response, according to a study published in Nature Neuroscience. Using virtual reality avatars, scientists found that participants' immune systems mobilised when they saw faces displaying signs of viral infections, such as skin rashes.
In the study, 248 healthy individuals wore VR headsets and were shown avatars with neutral expressions, signs of infection, or fearful expressions. The team measured responses through button-pressing tasks, EEG tests, and fMRI brain scans. Results indicated that participants reacted more quickly to avatars with infection cues, even when they appeared far away, and brain regions involved in threat detection showed altered activity.
Blood tests revealed activation of innate lymphoid cells (ILCs), early immune responders, when participants viewed infectious avatars. This activation was similar to that seen in individuals who had received an influenza vaccine. The authors noted that the behavioural system for avoiding disease is "exquisitely sensitive" to cues of sickness.
Dr Esther Diekhof of the University of Hamburg, not involved in the study, said it aligns with previous research on responses to potential contagion threats. However, Prof Benedict Seddon of University College London cautioned that it remains unclear whether these responses help fight actual infections, as the immune system may take longer to respond to real pathogens.
