SM was born in 1965 and experienced acute epileptic seizures from a young age. Initially, it was thought that he had a brain tumor causing epilepsy, but further investigation revealed that the seizures were due to bilateral atrophy in the medial temporal lobe, specifically in the amygdala.
One of the most intriguing aspects of SM was that he did not recognize fear, regardless of the stimuli he was exposed to. Despite normal intelligence and preserved cognitive functions, SM struggled with emotional information processing and specifically recognizing fear in others.
Researchers attempted to induce fear in SM through various means, including exposure to snakes and spiders, visits to haunted locations, and watching horror movies. Despite these efforts, SM showed no signs of fear and even displayed curiosity and excitement in situations that would typically evoke fear in others.
Another aspect of SM’s unique case was his inability to draw or recognize fear in visual representations. While he could describe fear theoretically, he consistently drew images of a crawling baby when asked to depict fear. This contrasted with his ability to accurately identify and express other emotions through drawings and descriptions.
A 2010 study conducted on SM highlighted the impact of a rare disease, Urbach-Wiethe, which caused calcium deposits in the amygdala, leading to damaged cells in this part of the brain. The study shed light on the role of the amygdala in processing fear and emotional stimuli. Despite SM’s lack of fear response, researchers could observe the impact of emotional memory mechanisms and the brain’s ability to prioritize stimuli based on past experiences. Understanding cases like SM’s could offer valuable insights into fear processing and potentially lead to innovative treatments for fear-related disorders.
Overall, SM’s case highlights how rare diseases can affect specific areas of the brain leading to unique neurological symptoms such as an absence or impaired recognition of emotions like fear. The study conducted on SM provides important information about how our brains process emotions like fear and how rare diseases can disrupt this process.
Furthermore, it is fascinating how despite not being able to recognize or experience
