A lot of people say they aren’t scared of anything, but the reality is every body is scared of something. Everybody, except a woman known as SM.
SM had a rare illness that caused damage to the part of her brain associated with fear. The amygdala “is involved in many of our emotions and motivations, particularly those that are related to survival”. In the same way that pain is a warning sign in attempt to protect you from danger, fear is a function of protection. Without fear you would constantly place yourself in dangerous situations with out responding to an impulse of survival.
The Amygdala- the area of the brain responsible for fear
The damage to SM’s amygdala caused her to lose the ability to feel fear. Scientists tested her on several simulated and real life situations such as being held up at gunpoint, watching scary movies, watching domestic violence. SM felt no fear what so ever in any of these situations. Scientists naturally would predict that with the loss of a functioning amygdala, SM would never feel fear again.
Yet, one day SM had a panic attack. The panic attack was brought on in an experiment where SM inhaled a small amount of carbon dioxide that created a short feeling of suffocation.
The fact that SM felt fear from a panic attack without an amygdala “illuminates some of the brain’s most fundamental processes and may have practical value in the study of panic attacks.” Additionally, it suggests that there may be an alternative center for fear responding to internal threats- such as suffocation or a heart attack.
This study is particularly fascinating because it shows just how little we know about ourselves and the world around us. It illuminates the flaws in our apparent definitive knowledge and encourages further research and speculation about what we know concerning the brain.
Link to Main Article:
http://www.nytimes.com/2013/02/04/health/study-discovers-internal-trigger-for-the-previously-fearless.html?ref=science
Link to additional Articles:
http://biology.about.com/od/anatomy/p/Amygdala.htm
Link to Picture used:
http://commons.wikimedia.org/wiki/File:Amygdala.png
ilikebioha
Henroid I think what you said is interesting and i wondered if SM could feel “learned fear”. Unfortunately, according to this article, http://www.psychologicalscience.org/index.php/news/releases/the-amygdala-and-fear-are-not-the-same-thing.html
,there is no way to test it. it claims that, ” the amygdala seems to be doing something more subtle: processing events that are related to what a person cares about at the moment.” So if you were to monitor the amygdala to see if learned fear would activate it, you wouldn’t actually be able to tell if that is what’s activating it.
sayrest4
I wonder how this disorder affects feelings such as phobias. Since phobias are fear, it would only be logical to think that they stem from the Amygdala. Maybe through studying people such as her we can find the root of these odd and often irrational fears.
http://www.apa.org/monitor/julaug05/figuring.aspx
sciencegirl025
Great article. It makes me think about what would happen if the malfunctioning of the amygdala lead to an increase in sensing fear, instead of a decrease in being scared. Check out this interesting article: http://inside-the-brain.com/tag/overactive-amygdala/ it describes symptoms of many people who have over active amydalas leading to increased anxiety and fear.
explodingllama342
It’s amazing what damage to the brain can do, especially since effects vary depending on location. For example, some brain injuries cause severe personality changes, turning friendly and outgoing people into angry and introverted individuals.
http://www.psychologytoday.com/blog/professor-cromer-learns-read/201203/after-brain-injury-the-dark-side-personality-change-part-i
biorob
I think this is a very interesting article. Ironically, I think that having damages related to the amygdala would be scary. I wonder what other events would cause SM to have another “panic attack.” Maybe because the carbon dioxide caused her to have a choking sensation set off another trigger in the brain. Fear can be very useful though, as stated in this article (http://news.discovery.com/human/psychology/fear-fearless-brain-emotion.htm). I guess if you physically cannot be afraid, what could you possibly be afraid of?
henroids
Fear can bring the nature vs. nurture debate into play. How much of your fear is learned and how much is natural? If you grow up taught to be afraid of falling, do you have a subconscious fear of heights or is the fear of falling natural? Is fear contagious? If you are watching a movie at home is is less scary than watching the same movie in theaters where you’re surrounded by people who might be terrified of the movie, causing you to become scared? These are some of the questions that scientists are trying to understand about emotions and nature vs. nurture.
Read more at: http://www.scientificamerican.com/article.cfm?id=factoring-fear-what-scares