Distance to threat the stranger had affected the fear response in the brain

Psychologists have found that fear caused by the spatially close events (appearance of a dangerous stranger), activates a different zone than if the threat is in the distance. In the first case, the Association with danger before being formed, slowly fades and it is easier restored. Similar threats are sustained activation of the cerebellum, which is not weakened during extinction and identifies the quick recovery of fear at the recurrence of the situation. Article published in the journal Proceedings of the National Academy of Sciences.

Fear as a mechanism of recognition of potential threats is necessary for survival — it allows us time to react to danger and select defensive strategy. However, sometimes traumatic events cause an exaggerated reaction and lead to mental disorders — phobias or post-traumatic stress disorder. To better understand how it occurs and how to treat these disorders, it is necessary to study the mechanisms of fear.

The memory of the traumatic events most often studied in the following way: impose a conditional stimulus (e.g. a particular sound) and then — traumatic unconditioned stimulus (usually electric shock). After that there is an Association of a conditional stimulus with the unconditional, and the next time the animal or person will be afraid of harmless sound.

The lack of the usual method lies in the fact that it is difficult to transfer to a trauma in real life, the conditional stimulus is presented only once and briefly, and the proximity of the unpleasant event is difficult to vary. However, it is knownthat the closer a person is to what is happening and the more involved, the greater the risk of developing post-traumatic stress disorder.

Scientists from Duke University under the direction of Kevin Labar (LaBar Kevin) investigated the fear response in the brain in almost real-life conditions using virtual reality. 49 volunteers were placed in an fMRI scanner and shown a series of scenes through VR glasses. Study participants walked through the virtual passage between two walls, and from time to time in front of them suddenly appeared one of the four virtual people.

Two of the strangers became a “threat”, and the remaining two “safe”. It’s not the appearance (for different volunteers “threat” became different men), and that in half of the cases simultaneously with the appearance of “dangerous” men the participants were zapped on the wrist is uncomfortable, but not painful. One of the two persons in each category were very close (60 centimeters), and the second at a distance of three meters. Immediately after the male study participants noted the likelihood of a shock on a four-point scale. Just every stranger appeared ten times, and in total the volunteers received ten shocks.

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