Fear is a complex emotion that roots deeply in the human heart, forming an instinct to avoid danger and protect oneself from harm. However, excessive fear can diminish the quality of life.
Fear is a complex emotion that roots deeply in the human heart, forming an instinct to avoid danger and protect oneself from harm. However, excessive fear can diminish the quality of life.
The amygdala, located in the brain’s temporal lobe, is known as the “fear center.” Although scientists have long recognized the amygdala’s crucial role in processing fear signals, its specific function in human fear recognition remains unclear. Recently, American researchers have explored this mystery.
This research was conducted by Adrian, a professor of psychology and neuroscience. He observed a 38-year-old woman suffering from a rare genetic disorder that damaged her amygdala, impairing her ability to recognize fear expressions in others.
He showed the woman and other volunteers a series of images depicting various emotional expressions, including a fearful face and a joyful face. Typically, people with normal brain function tend to gaze directly into the eyes, especially when faced with fearful expressions. However, the woman was unable to instinctively focus on the eyes and instead stared blankly at the images, concluding that there was nothing particularly expressive in the faces shown.
Notably, when reminded to pay attention to the eyes in the images, she could identify which person was in a state of fear. However, her ability to do so was fleeting; she required constant reminders to focus on the eyes of the depicted individuals.
Researchers concluded that while the damaged amygdala could not direct the visual system to collect information, its ability to process visual signals remained intact. In other words, apart from analyzing the signals from the eyes, the amygdala also alerts individuals to pay attention to the eyes of others.
The more sclera (the white part of the eye) is exposed, the easier it is to intimidate
Researchers at the University of Wisconsin (USA) took the investigation further and discovered that on the faces of individuals expressing fear, the sclera is more exposed.
During the experiment, researchers showed volunteers a series of emotional images and simultaneously used an MRI machine to measure their brain activity. Results showed that the amygdala of volunteers reacted only to wide-open eyes due to fear, with no reaction to the pupils or iris. The level of amygdala response was directly proportional to the size of the exposed sclera. Researchers speculated that the variation in scleral size could be the only “fear” signal that the amygdala could recognize and respond to.
Seeking New Treatment Methods for Phobias
Appropriate fear can help individuals avoid danger and protect themselves from harm. However, fear of objects or situations that do not typically frighten ordinary people can be troublesome, confusing for others, and even severely impact daily life and work. Therefore, understanding the brain’s mechanisms for recognizing and alleviating fear could liberate those who are overwhelmed and haunted by their phobias.
Neuroimaging studies indicate that even if other parts of the brain are focused on certain situations, perhaps unaware that they are attending to a terrifying object, the amygdala remains vigilant at every moment, warning of impending danger! For instance, if a photo of a face displaying an emotion briefly appears on the screen and is then replaced by a neutral face, participants in the experiment would claim to have only seen a neutral expression. Meanwhile, the amygdala senses the need to increase its activity when the emotional face appears, returning to normal when the neutral face is shown.
The amygdala plays a crucial role in recognizing and alleviating fear, especially during the initial phase of the process. If there were a drug that could influence the amygdala, it might provide a therapeutic effect for phobias and panic attacks.
