The Amygdala’s Role in Experiencing Fear
By: Muhammad Talha Moazzam, PS 101 A9, December 14 2014
Introduction:
Fear is one of the most basic and powerful emotions that animals, including human beings, possess. Fear is an unpleasant emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat. If a fear becomes so great that it starts interfering with a person’s daily life, it could mean that the person is suffering from a fear or an anxiety disorder.
Research on emotion has become a popular topic as a result of the successful discovery of the mechanisms involved with the expression of fear (LeDoux, 1998). One of the most repeatable findings is the fields of psychology and neuroscience is that the amygdala,
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For all categories presented, she always rated at the lowest level and her PANAS-X score for fear was extremely low as well but she did experience other emotions (Feinstein et al. 2010). Despite the lack of comparative data, the patterns observed indicated that SM could not experience fear at all (Feinstein et al. 2010). The fact that SM failed to fear such a variety of fear inducing things could make one believe that she just never encountered such stimuli during the critical period of her life. However that was not the case, as when she was questioned, she recalled several events that fit into the fear inducing category. These included being held on gunpoint, almost being killed in a domestic violence incident, death threats etc (Feinstein et al. 2010). Further investigation of her background led to the discovery that she was from an area where a lot of criminal actions took place and her lack of understanding of fear caused her to be the victim of several criminal incidents. SM reported not being scared during these events but she did feel angry and upset (Feinstein et al. 2010). Coming out of such harsh conditions unscathed led the researchers to believe that SM was immune to the effects of PTSD (Post Traumatic Stress Disorder) (Feinstein et al.
Fear. Fear Is not just being afraid of that Clown that just follows you around on halloween night scaring everybody in sight. Fear is the emotion in the back of your mind that torments you every waking moment. It tells you what to say and keeps you from letting things out, even when sometimes the best thing for you is to let it out. “Fear is the little death that brings total obliteration.” quoted by unknown.
Signal processing within the amygdala is further regulated by interactions with a network of external structures. In particular, the dMT and its projections to the CeL have been demonstrated to play a role in fear memory retrieval. Notably, the dMT is assumed to be extensively modulated by opioids considering its innervation with opioidergic fibers and the high expression levels of MORs. Previous studies have reported the MOR system in the PVT, as part of the dMT, to be involved in managing physical pain. Moreover, social pain, which describes social rejection, being excluded or not being liked by others and which is associated with symptoms of anxiety and depression, appears to involve the MOR system in the PVT (Hsu et al). However, so far a direct implication of
Fear is an emotion that many people around the world for many years have dealt with. Fear can sometimes be harmful, but, on the other hand, many people also believe that fear is not always a harmful emotion. Fear can help keep one safe from danger. However, certain amounts of fear can cause harm to the body. It all just depends on how well you deal with it.
Fear is a feeling created in a response to a perceived danger. Fear can produce pleasure, heighten awareness, be in the form of phobia, a fear of the unknown and an instinctual response to danger.
Fear is something everyone feels at some point in their life. Fear is a feeling that your body produces in dangerous, threatening, or scary situations. It is the ability to identify danger and make a choice to either confront that fear or flee from the situation.Why do we human act in strange ways when reacting to fear in a negative way. Fear is a rash feeling that cause affect on humans. Fear would negatively affect people in ways to make them to unrashinal things. Positive things that can come out of fear is being alert and being more self aware.
What is fear? According to kidshealth.com, fear is one of the most understood human feelings. It is computerized into the nervous system and works like an instinct. Starting as small babies, humans
The amygdala is the name of the collection of nuclei found in the frontal portions of the temporal lobes in the brains of all primates (the term Amygdala derives from the Greek word, αμύγδαλο or amýgdalo meaning almond). This collection of nuclei is a small almond shaped structure located on either side of the thalamus at the lower end of the hippocampus in the limbic system which is located in the frontal portion of the temporal lobe. Considering the human brain is bilaterally symmetrical, there are two amygdalae, both located in relatively the same place, but one in the left side of the brain, and one in the right side of the brain. Although this structure is merely as big as an almond, there are vast amounts of functions that begin and travel
When a person develops PTSD, the amygdala has stored the sights, sounds, and smells associated with the event. If one or more of these stimuli are encountered, the amygdala will trigger a danger signal and prepare the body. The amygdala is believed to have a primary role in hypervigilance, which can be protective when a person is in a potentially dangerous situation. However, for those with PTSD, this can be counterproductive, since the amygdala remains overactive and interferes with sleep or being able to lets one’s guard down in a safe situation.
The two brain structures that are most frequently linked to human emotion are the amygdalas and the medial portions of the prefrontal lobes (Pinel, 2014). The amygdalas are only one section of the limbic system, it is the “almond-shaped nucleus in the anterior temporal lobe” (Pinel, 2014, pg. 70). The amygdalas have been researched more than any other section of the limbic system. The amygdalas are most commonly associated with the emotion of fear, however research is showing that the amygdalas actually play a role in “evaluating the emotional significance of situations”, whether the emotions being felt are positive or negative (Pinel, 2014, pg. 436). Even though research has shown the amygdalas play a larger role with emotions, brain imaging
What is fear? Fear is an antique and common sensation in creatures. It can be defined as the feeling that you are in danger. Fear is most likely complemented with external symptoms. When it is not defensible by the existence of real danger and when it is also complemented with a regular avoidance of the circumstances that lead to it, then we have a term referred to as a phobia.
Chronic stress is known to cause detrimental effect on various forms of learning and memory. The basolateral amygdala (BLA) plays a crucial role in modulation of stress and related physiological effects including learning. This study was designed to evaluate the effects of excitotoxic lesion and temporary inactivation of the BLA on chronic stress-induced hippocampal-dependent spatial learning using partially baited radial arm maze task. The principal neurons in the BLA were either ablated using ibotenic acid or temporary inactivated using lidocaine prior to chronic immobilization stress. Chronically stressed rats showed impaired spatial learning with declined percentage correct choices and enhanced reference memory errors. We also observed the enhanced working memory errors although it was not consistent during all the blocks. The neurotoxic lesion and temporary inactivation of the BLA prior to stress prevented the impaired spatial learning with an increase in percentage correct choices and reduction in reference memory errors compared to stress group. During the retention, lesion and inactivation of BLA prior to stress, was able to preclude the chronic stress-induced enhanced reference memory errors and poor performance. Interestingly, stress-induced spatial learning deficits were associated with enhanced plasma corticosterone levels, which were partially prevented by the neurotoxic lesion and temporary inactivation of the BLA. Further, the partial reductions in plasma corticosterone levels were correlated with prevention of spatial learning and memory deficits. These results demonstrate that amygdala modulates chronic
Fear is something that large amounts of people have encountered at least once at some point in their lives. It has been said to have caused a variety of outcomes, many of them being largely negative. Therefore, it is a common human response to react to fear by counteracting it with positivity and/or success. The idea people have of what fear is depends on the person. In the article “How Fear Works”, for example, fear is defined as a “chain reaction in the brain that starts with a stressful stimulus and ends with the release of chemicals” (Layton 1). The website “Psychology Today” defines fear another way, calling it “a vital response to physical and emotional danger” ("Fear Paranoia”). There are several other definitions people have on the
This small area is placed to receive stimuli from all the sensory cortices and other sensory areas. It is together with the hippocampus, considered a part of the limbic system. The amygdala receives input from all levels of sensory processing. From thalamus, it receives early sensory signals that have not yet been highly analyzed. A more thorough analysis of a stimulus is done in the sensory cortex that also projects to the amygdala .
Fear is the feeling when a person’s heart starts beating rapidly and they begin to sweat. Their breathing becomes raspy and knots begin to form in their stomach. Fear is a natural instinct for human beings. According to psychology today “Fear is a vital response to physical and emotional danger” (All about fear). Fear is usually due to an experience that made a person’s body react in an unfamiliar state. Fear can keep people from dangerous situations, also a set up for building confidence, and overcoming fear is an obstacle.
According to my dictionary, Fear is an unpleasant emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat. When the word "fear" comes to my mind, I think of an emotion that's caused by a bad situation. There are many things in this world that put fear in me. My greatest fears are computer viruses, thugs, sick people, and clowns. Each of these fears make me very scared and give me goosebumps.