Witnessing Fear in Others Can Physically Change the Brain

Summary: A new study reports traumatic experiences can alter the brain, leaving people more vulnerable to psychological problems.

Source: Neuropsychopharmacology.

Scientists at the Virginia Tech Carilion Research Institute have found that witnessing trauma in others may alter the way information flows in the brain and it may lead to PTSD implications.

Negative emotional experience leaves trails in the brain, which makes us more vulnerable. Traumatic experiences, even those without physical pain, are potential risk factors for mental disorders.

Post-traumatic stress disorder(PTSD) is an anxiety disorder that can develop in some people after they go through a shocking, scary, or some traumatic event. Most people who live through traumatic events do not develop the disorder, but about 7 or 8 out of every 100 people will experience PTSD at some point in their lives.

According to a 2008 RAND Corp. analysis of multiple studies on post-traumatic stress and depression in previously deployed service members, people who came to know about a fearful incident, such as a gunfire exchange, were just as likely to experience post-traumatic stress disorder as the people who originally had lived through the incident.

In previous studies, the researchers at the Virginia Tech Carilion Research Institute, discovered that rodents who observed stress in their counterparts but did not experience it firsthand developed stronger than normal memories of their own traumatic experiences — a behavioral trait related to some humans who experience traumatic stress.

Based on the study results, the researchers examined whether the part of the brain responsible for empathizing and understanding the mental state of others, called the prefrontal cortex, physically changes after witnessing fear in another.

Lei Liu, a postdoctoral researcher in the lab, assessed transmission through inhibitory synapses that controls strength of the signals arriving in the prefrontal cortex from other parts of the brain in mice who had observed a stressful event in another mouse.

According to the researchers, this findings may possibly allow more communications via the synapses in the deep cellular layers of the cerebral cortex, but less so in the superficial ones. It’s not yet completely understood how the circuits have altered, only that they have indeed changed.