Close-up threats that invade your personal space activate the brain’s primitive ‘survival instinct’ and are more likely to trigger PTSD than those that are further away, study says
- Researchers saw evolutionary older parts of the brain activated for near threats
- But those at least ten feet away activated problem-solving areas of the organ
- They said the research may offer new methods for treating PTSD sufferers
Threats that invade your personal space and activate the brain’s ‘survival instinct’ are more likely to trigger PTSD, a study has warned.
Researchers made the find after asking 49 participants to lie inside an MRI machine and watch a virtual reality headset, that showed them either walking through a dark alleyway or bright tree-lined street.
As they watched avatars then appeared at a distance of either two or ten feet, and gave them a slight electric shock.
Brain scans showed nearby avatars were ‘more frightening’ and engaged an evolutionary older part of the brain, the limbic and mid regions, while the faraway ones activated ‘higher-order’ problem-solving areas.
The response triggered by the ‘survival’ circuitry also proved harder to extinguish, the researchers said, and was triggered even after the avatars stopped producing shocks.
Participants watched videos where avatars appeared at a distance of either two or ten feet (as shown above). Researchers then monitored how their brains responded
‘Clinically, people who develop PTSD are more likely to have experienced threats that invaded their personal space, assaults, or rapes or witnessing a crime at a close distance,’ said study author and psychology professor at Duke University, Kevin LeBar.
‘They’re the people that tend to develop this long-lasting memory.’
Talking about the results, he said: ‘We think that the cerebellum might be an interesting place to intervene. Clinically, it’s a new interventional target.’
‘If you can somehow get rid of that persistent threat representation in the cerebellum, you might be less likely to reinstate (the fear) later on.’
The researchers hope their study, published in the Proceedings of the National Academy of Sciences, will lead to new methods for treating PTSD.
The team also found that memories of danger from nearby avatars were harder to extinguish
The experiments for the study took place over two days, with shocks given when threat avatars appeared on the first day.
This was then repeated on the second day, before shocks were removed to identify whether brain’s continued to identify threats and how long for.
The 3D virtual reality experience was fitted with backgrounds and ambient sounds to make the experience seem more realistic.