The 9/11 attacks in the New York impacted the psychological processes of those who were not directly exposed to them, finds a new study.
The study, which focused on college students in Massachusetts, found that even those who were not directly connected to New York or Washington showed increased stress responses related to the attacks.
Ivy Tso from the University of Michigan and her colleagues' study took place within one week of the attacks.
The participants were shown a series of 90 pictures, 30 of which contained images of the attacks while the others were defined as either 'negative' but not related to the attacks, or 'neutral'.
The team then measured the brain activity of the participants to detect signs of anxiety and stress.
"The results of our study indicate that participants' brainwave responses during processing of the images deviated from normal in proportion to their self-report distress level directly related to the 9/11 attacks," said Tso.
These stress-related neural deviations are analogous to the clinical phenomena and abnormal cognition observed in individuals with PTSD (e.g., diminished attention, hypervigilance, suppression of unwanted thoughts).
The study has been published in the Journal of Traumatic Stress.