One study also discovered that there was a disconnect between the amygdala and prefrontal cortex, which normally helps an individual override or minimize the fear response.Īside from the fear felt when someone with a phobia meets their nemesis, these individuals are also in a heightened state of arousal they always expect to see their trigger, even in situations where it is not particularly likely to appear. Given our understanding of the amygdala’s involvement in the fear response, it is unsurprising that there is a link between phobias and heightened activity in this region. While there are still many questions left unanswered, scientists have uncovered some of the neural events that underpin phobias. In general, however, the origin of a phobia is tricky to unravel - after all, most people who witness someone falling off a bridge do not develop a phobia of bridges, so there is more to it than simple experience. Sometimes, the origin can be relatively easy to understand: someone who witnesses someone falling off a bridge might later develop a phobia of bridges, for instance. There is no hard-and-fast reason a phobia will develop both genes and the environment can be involved. They can attach to pretty much anything and significantly impact people’s lives. As mentioned earlier, phobias are often an irrational and overactive fear of something that, most often, cannot cause harm. Medical professionals class phobias as an anxiety disorder. The authors of the study hope that their findings might one day help design ways to treat people with anxiety disorders and phobias who can become paralyzed with fear. Messages that run along these paths cause an animal to freeze with fright. The researchers found a bundle of fibers that connect one region of the cerebellum, called the pyramis, directly to the PAG. The cerebellum is also sent sensory information, which it uses to help coordinate movement. The PAG receives various types of sensory information about threats, including from pain fibers. It is generated by cross talk between the periaqueductal gray (PAG) and the cerebellum. Sometimes, staying motionless is the best plan for instance, if you are a small mammal or if you are well-camouflaged, staying still could save your life.Ī 2014 study identified the neurological root of the freezing response. When frightened, most animals freeze for a few moments before they decide what to do next. The idea of our bodies preparing to fight or fly makes good sense from a survival standpoint - but how would freezing be of any use? An animal that simply stands rooted to the spot would make an easy snack for a predator, you might think. So, we get to experience the rush of fear before our more reasonable brain centers dampen it down. This partly explains why people enjoy watching scary movies their sensible “thinking brain” can overpower the primal parts of the brain’s automated fear response. If the hippocampus and prefrontal cortex decide that the fear response is exaggerated, they can dial it back and dampen the amygdala’s activity. They help us understand whether our fear response is real and justified or whether we might have overreacted somewhat. inhibit the production of tears and salivation, explaining the dry mouth that comes with a frightīoth the hippocampus - a brain region that is heavily involved in memory - and the prefrontal cortex, which aids high-level decision making, also help control the fear response.reduce activity in the stomach and intestines, which explains the feeling of “butterflies” in the stomach.Circulating cortisol turns fatty acids into energy, ready for the muscles to use, should the need arise.Ĭatecholamine hormones, including epinephrine and norepinephrine, prepare muscles for violent action. The body also releases cortisol in response to ACTH, which brings about the rise in blood pressure, blood sugar, and white blood cells. The pituitary gland then secretes adrenocorticotropic hormone (ACTH) into the blood.Īt this time, the sympathetic nervous system - a division of the nervous system responsible for the fight-or-flight response - gives the adrenal gland a nudge, encouraging it to squirt a dose of epinephrine, also known as adrenaline, and other catecholamines into the bloodstream. The pituitary gland is where the nervous system meets the endocrine, or hormone, system. The amygdala signals the hypothalamus, which then activates the pituitary gland. It plays an important role in the processing of emotions, including fear. The fight-or-flight response begins in the amygdala, which is an almond-shaped bundle of neurons that forms part of the limbic system.
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