Italian scientists were able to reduce physiological indicators of fear by transcranial magnetic stimulation of the prefrontal cortex. To do this, they trained volunteers to fear the shock at the sight of a particular image, and the next day, showing the room again, non-invasive stimulated dorsolateral part of their prefrontals crust. On the following day the electrical activity of the skin — an indicator of autonomic nervous system and physiological marker of fear was reduced. As I write , scientists in the journal Current Biology, this reduction in fear is regulated by exposure to memories of threat through the prefrontal cortex.
Fear is one of the oldest emotional States, which largely determine the evolution of individual organisms: it is the fear allows you to avoid potentially dangerous stimuli and, therefore, increase the survival rate. However, modern man’s fear is not always desirable and useful sense: often this feeling is irrational and can significantly reduce quality of life. In many ways, so neuroscientists and psychologists have for a long time looking for ways to save people from fear, and this task helps psychotherapy: she, however, takes quite a lot of time.
Another potentially effective method — stimulation is responsible for the feeling of fear parts of the brain. The fear of many is governed by the work of memory: reminiscences about the threat (or any other terrifying object, not necessarily the objectively dangerous) allow a person, on the one hand, to avoid undesired stimuli, and with another — to show a defensive response, if the meeting did take place. For working memory, in turn, responds to the cerebellum, because the cerebellum — the structure deep to reach it using non-invasive methods are not so simple. That is why for the targeting of unwanted memories that cause a sense of fear, you need to find another way — for example, stimulation of the frontal lobes.
Giuseppe di Pellegrino (di Guiseppe Pellegrino) from the University of Bologna decided to focus on the dorsolateral part of the prefrontal cortex — the area responsible for emotional response and potentially regulate unwanted memories, including fearful. For this, they held a three-day experiment, which was attended by 84 people.
On the first day of the experiment, the participants were shown images of two rooms: when the volunteers “fell” in the first room, their wrists lightly electrocuted (the second room was a control in her shock didn’t hit). On the second day, the participants again were shown the room, and ten minutes after the presentation stimulated or dorsolateral portion of the prefrontal cortex (left and right) using transcranial magnetic stimulation (TMS) or parietal lobe (for control conditions). On the third day, the scientists repeated the experiment, which was conducted on the first day: I showed participants two rooms.
Fear of the participants, the scientists measured through the assessment of electrical activity of the skin — physiological indicator of activation of the autonomic nervous system (including in response to a threatening stimulus). By this measure, all participants were able to learn the connection between the room and the shock on the first day: the second day at the sight of the room the electrical activity of their skin increased (p < 0.05), which means that they actually felt fear.
On the third day, however, the electrical activity of the skin was significantly (p < 0.05) below — but only among those participants who stimulated the dorsolateral part of the prefrontal cortex (as in right and left hemisphere). The test stimulation of the occipital lobes and absence of stimulation at all to such an effect is not given.
Given the fact that TMS-regulation of fear worked in the case of reconsolidation memories (that is, when they are caused by external stimulation), the researchers suggested that stimulation of the prefrontal cortex was affected by it in memory, making the memories about the threat not so bright and, consequently, reducing fear of it.
To forget the unwanted memories and you can own, without the help of magnetic stimulation. Last year, scientists foundthat the brain spends more effort, and such enhanced processing of memories actually helps to get rid of them.