MONDAY, Jan. 24 (HealthDay News) -- Continual exposure to stress
prompts neural activity changes in those parts of the brain that
control fear, vigilance and emotion, a new study suggests.
The finding stems from an analysis of brain scans taken among
troops recently deployed to Afghanistan, and is reported in the
Jan. 18 issue of the journal
"For the first time we can now conclude that the effects on the brain really are due to experiences in combat," study first author Guido van Wingen, of the Donders Institute for Brain, Cognition and Behaviour at Radboud University Nijmegen in the Netherlands, said in a university news release.
Van Wingen along with colleagues at the Military Mental Health
Research Centre and the Rudolf Magnus Institute of Neuroscience in
Utrecht tracked 36 soldiers who were deployed to Afghanistan as
part of the International Security Assistance Force (ISAF) mission
between 2008 and 2010.
Before and after their mission, the soldiers underwent brain
scans, which were compared with those taken among a group of
soldiers who were not deployed and had instead remained in their
barracks back in the Netherlands during the study period.
Questionnaires regarding combat experience were also completed.
The research team found that although none of the deployed
troops developed post-traumatic stress disorder, all of the
soldiers in Afghanistan had experienced a ratcheting up of activity
in the amygdala and insula regions of the brain, which are
responsible for regulating fear and vigilance.
Such increased activity appeared to last for a minimum of two
What's more, the investigators observed that neural activity in
the region of the brain that is responsible for emotional
regulation differed among the deployed soldiers. The kind of
changes that took place depended on how the soldiers
perceived the experiences to which they were exposed, the
study authors noted. For example, the degree to which a soldier
perceived a roadside bomb explosion to be a threat predicted the
degree of activity change in their brain's emotional control
For more on brain function, visit the
U.S. National Library of Medicine.