The brain and body are far more proactive in fighting infections than previously thought. A groundbreaking study published in Nature Neuroscience, a leading academic journal under Springer Nature, shows that the brain can detect potential sources of infection in the surrounding environment and prime the body’s immune defenses in advance—even before any physical contact, and even within virtual reality scenarios. This discovery highlights a dynamic, active collaboration between the brain and body to combat infections.
Traditionally, threats from predators trigger the "fight-or-flight" response, but pathogens like bacteria and viruses pose a more silent risk. Contact with pathogens triggers immune responses, including rapid innate immune cell activity and slower adaptive immunity. However, little was known about how the brain and immune system coordinate before an infection actually occurs—until now.
Led by Camilla Jandus and Andrea Serino from the University of Lausanne, Switzerland, the research team designed a virtual reality experiment involving 248 healthy young adults. Participants were exposed to virtual human faces: some showed visible signs of infection (such as rashes or coughing), while others displayed neutral or fearful expressions. When the virtual figures with apparent infections entered the participants’ "peripersonal space" (the close proximity around the body), the participants exhibited heightened sensitivity to touch—indicating that the brain’s peripersonal space system was on high alert.
Using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to measure brain activity, the researchers found altered activity in brain regions responsible for integrating sensory information and spatial awareness when infected-looking figures approached. This neural response was not observed when participants faced neutral or fearful faces.
Blood samples from participants further revealed that exposure to virtual infected figures was associated with increased activity markers in innate lymphocytes—key components of the immune system. This response closely resembled the body’s reaction to real infections, such as those triggered by flu vaccines, compared to control groups.
The study authors conclude that the brain can coordinate early physiological responses to potential infections, effectively priming the immune system for action. This proactive collaboration between the brain and body opens new avenues for understanding how the nervous and immune systems interact to protect against disease, potentially informing future strategies for enhancing immune readiness.