The brains of soldiers who are continuously exposed to trauma on the battlefield may undergo adaptations that make them more vigilant against possible threats, according to a new study published in the journal Molecular Psychiatry. The findings also showed that these changes may persist long after veterans have returned home.

For the study, researchers from Radboud University in the Netherlands took brain scans of soldiers both before and after they went off to war in Afghanistan. Participants were also asked to fill out surveys about their experiences in combat.

The results showed that soldiers who were exposed to the trauma of combat experienced alterations to the neural circuitry of areas of the brain associated with vigilance and threat perception. These changes made them more aware of potential threats, possibly allowing them to respond faster. These changes persisted for at least two months after soldiers returned home.

While none of the participants developed post traumatic stress disorder during the course of the study, the researchers believe that there may be a connection between the condition and the effect they observed. They are currently working on further investigations to study this potential link.