The Curious Case of SM

Devika

Invisibilia, is a podcast that delves into how human behavior is controlled by various subliminal forces that shape our ideas, beliefs and assumptions. Hosts Lulu Miller and Alix Spiegel bring together narrative storytelling and science to provide fresh perspective about these invisible guiders in our lives. Episode two of Invisibilia, ‘Fearless’, focuses on one of our most critical emotions - fear - and the rare case of a woman who is unable to feel fear at all.

Fear is an emotion that we are biologically programmed to feel. It dictates various aspects of our lives and also narrows down the circle of our experiences. But is it possible to not experience something that has evolutionarily been critical for our survival? It turns out, around 400 people on earth have been identified with the inability to feel fear (Miller & Spiegel, 2015). Formally known as the Urbach-Wiethe disease, this rare genetic disorder causes calcium buildup in the amygdala - the part of the brain responsible for processing fear. This calcification biologically inhibits an individual to feel fear. The condition has two main symptoms: an extremely hoarse voice and small bumps around the eyes. But what does the life of someone with Urbach-Wiethe look like? Let us find out!

The hosts of the show had the opportunity to interact with an individual who with having Urbach-Wiethe, is able to lead a normal life. For confidentiality reasons, she is referred to as ‘SM’. As you may imagine, living without fear is extremely dangerous. If SM were to be threatened, her brain would not register the fear that would immediately arise in you or me. This particular reason is why scientists have been careful about guarding her identity - to protect her from being taken advantage of. Having said that, Miller and Spiegel were lucky enough to send a list of questions to Daniel Tranel, a researcher who has been studying SM for the past twenty years. His observations show that SM’s amygdala was completely calcified during childhood, which is why her brain fails to signal any kind of fear to the rest of her body. Apart from being the mother of three children, SM has normal intelligence levels and shows no problem regulating other emotions. When Tranel asks her if she has a sense of what it would be like to be afraid and feel fear, SM replies, “No, not really.” She adds, “I wonder what it's like, you know, to actually be afraid of something.” (Miller & Spiegel, 2015). Since this podcast provides first-hand voice recordings of SM, it is hard to miss the hoarseness of her voice - a glaring symptom of Urbach-Wiethe. Other factors such as the stories that SM recounts, also prove that the portrayal of this condition is quite accurate. But what have researchers learned from the curious case of SM and how did they derive any conclusions?

To test this condition, Tranel and other scientists have performed all kinds of experiments, with the goal to instigate fear. They have exposed her to terrifying snakes, which resulted in SM being restrained from playing with ones that could actually be harmful to her! They tried to condition a fear response by randomly assaulting her with the sound of a jarring horn, which resulted in no response at all. Furthermore, when asked to draw a face with a fearful expression, SM was unable to conjure up any image whatsoever. These failed attempts prove that SM seems to be emotionally blind to the experience of fear. In order to live life to the best of her ability, she relies on other paths such as logic, to help her make the right choices.

The unusual case of SM leads one to ponder upon how life would be without fear. The inability surely makes one more prone to terrible things in life, as the concept of danger will not exist. However, the brain will not register these fear-inducing events as frightful or terrible. On the other hand, the ability to feel fear makes one less prone to danger as they are aware of its consequences. The downside is that this can bring about huge amounts of unnecessary worry and anxiety. In other words, a life full of fear and a life without fear both come with certain implications. This odd bargain leads to the following dilemma: is it better to have a ‘fearful’ or ‘fearless’ life?

References

Miller, L & Spiegel, A. (Host). (2015, January 16). Fearless [Audio podcast]. Reterieved from https://www.npr.org/programs/invisibilia/377515477/fearless