Biology 202

2006 First Web Paper

On Serendip

Panicking, sweating, restlessness, increased heart rate, and, overall, feelings of fear these are a few of many symptoms associated with anxiety disorders. Humans are entitled to their own share of anxiety episodes but for some humans these episodes are at a higher level by which their anxieties have become debilitating to their lives. There are a myriad of anxiety disorders such as compulsive stress disorder, post traumatic stress disorder, and phobias. Furthermore, I will investigate the neurobiology of phobias and find out what factors contribute to the development of a phobia in a person.

Phobias are just one example of anxiety disorders. A phobia is an intense and strong fear of something that poses little or no danger to us at all. Some interesting phobias are: heights, dogs, water, flying, blood, and even pennies. Most adults with phobias such as the ones previously listed realize that their fears are for the most part irrational but they tend to find it difficult to face or even think about facing their phobias(1). The act alone can cause some people to have panic attack or severe anxiety. To understand this specific disorder, we must look at the general picture. Some studies have suggested that there are certain genes that are related to the development of an anxiety disorder such as a phobia. Along with this, there have also been studies suggesting further research in the amygdala, which is the part of the brain that is responsible for fear responses as well as storing memories of fear. Research in this direction is valid because from what we discussed in class and from what I know, the amygdala is like a communication center between the parts of the brain that process incoming sensory signals and the parts of the brain that interpret the signals (2). So if this is the case, then how these signals are interpreted is key to finding out why people with phobias respond the way they do to certain objects, animals, or situations. A question posed by some researchers is whether or not these disorders are actually brain disorders. Perhaps, having a phobia is just the result to being conditioned to react a certain way in response to a given situation, animal or object. In an article by Lea Winterman, psychiatrist Scott Rauch explains that what researchers know about fear and the brain comes from animal research on specifically laboratory rats (3). Rauch explains the fear conditioning model as a model in which rats are conditioned to fear a neutral stimulus, like a specific tone, by pairing it with something aversive, such as an electric shock. Then researchers eliminate this fear by repeatedly playing the tone without the accompanying it with electric shock (3). This model brought back attention to the amygdala.

In Winterman's article, a New York University psychologist Joseph LeDoux, PhD, and researchers found that there is a double pathway leading to and from the amygdala. One path begins directly from a frightening sensory stimulus like seeing a dog or hearing a plane (as phobias of course) to the amygdala in just a few thousandths of a second (3). The second pathway, which is shorter and slower, first travels to the higher cortex before reaching the amygdala. This shorter pathway is apparently fast but it is not precise so the fast pathway therefore, is the early warning system for the brain and this is what leads people with phobias to experience the physical manifestations of fear such as increased heart rate, sweating, and restlessness, according to LeDoux (3).

I agree with the idea of a double pathway but I am not entirely convinced that a phobia is in result to a brain disorder, as stated before. The amygdale sends signals in response to a stimulus that poses a threat to the organism but what exactly determines whether or not a stimulus is dangerous or poses a threat to the organism? If our experiences determine what we perceive to be dangerous and what we perceive to be harmless, then how can researchers say that phobias are part of a brain disorder? I feel like the function or information processing of the amygdala stays the same among regular people and phobics, no matter the stimulus and so being a phobic does not necessarily mean that one has a brain disorder or malfunction of one of the parts of the brain like the amygdala. Instead, I think that the response or actions of the phobic has to do more with his or her personal experiences and the conscious awareness of their fear.

Treatment of some phobias seems to be the next plan of action for those who find themselves in constant fear of seeing or facing their phobias. Presently there are two general forms of treatment for anxiety disorders: anxiety disorder-medication and specific types of psychotherapy (4). For phobias, psychotherapy has been the only form of treatment to be primarily effective on phobics (4). However, Beta-blockers, such as propanolol, are commonly used to treat heart conditions but they have also been found to be effective in certain anxiety disorders, particularly in social phobia. So if one knows that he or she has a presentation coming up and are afraid of a large group of people, then your doctor may prescribe a beta-blocker that can be taken to keep your heart rate from skyrocketing, your hands from skating and sweating, and other physical symptoms from associated. This does not seem to far fetched because if Emily Dickinson is right then, if we change the way the brain responds to a stimulus then we have in turned changed behavior, so if the doctor gives the girl prescription to take, then a few hours later, her behavior will surely change. Furthermore, anxiety disorders are pretty complex situations and phobias specifically, are very tricky but with new ongoing research, we will continue to learn how certain signals are processed as compared to other signals in or near the amgydala.

Bibliography
1 The Neurobiology of Anxiety Disorders: A Preliminary Investigation , an article explaining anxiety disorders

2) National Institute of Mental Health: Anxiety Disorders., talked about the amygdala

3) Figuring out Phobias article by Lea Winerman

4). Consumer: Anxiety Disorders.


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