A study has revealed that if a person gets to know something serious from his/her loved one or even strangers like a gunfire exchange, it can lead to change in information flow in the brain leading to post traumatic disorder.
Scientists in the study, published in Neuropsychopharmacology, found that fear in others may change how information flows in the brain.
Post-traumatic disorder is a kind of stress disorder which can develop in some people after experiencing a shocking, scary or dangerous event, says the National Institute of Mental Health.
"Negative emotional experience leaves a trace in the brain, which makes us more vulnerable," said lead study author Alexei Morozov from Virginia Tech Carilion Research Institute in the US.
"Traumatic experiences, even those without physical pain, are a risk factor for mental disorders," Morozov added.
The team observed that most people who live through dangerous events, do not develop the disorder but there are chances of 7-8 out of 100 people suffering the post-traumatic disorder at some or the other point in their lives.
"PTSD doesn't stop at direct victims of illness, injury, or a terrorist attack; it can also affect their loved ones, caregivers, even bystanders -- the people who witness or learn about others' suffering," Morozov stated.
It was further examined whether prefrontal complex, part of brain responsible for empathizing and understanding mental state of others, changes physically after witnessing fear in others.
Lei Liu, a post-doctoral researcher in the lab, measured transmission through inhibitory synapses that regulate strength of the signals arriving in the prefrontal cortex from other parts of the brain in mice who had witnessed a stressful event in another mouse.
"Liu's measures suggest that observational fear physically redistributes the flow of information," Morozov said,
"And this redistribution is achieved by stress, not just observed, but communicated through social cues, such as body language, sound, and smell."