The Brain's Role in Emotion
Although technological advancements have been able to detect internal differences from one emotion to the next, it doesn't hold true for all emotions. Fear is the emotion most studied by psychologists, perhaps because it's effects are among the most pronounced out of all emotional responses. Brain research has found that the amygdala, a tiny structure in the limbic system, plays a critical role in emotion. Brain imaging scans have shown that this tiny cluster of neurons becomes activated when people view pictures of threatening faces. Researchers have found that damage to the amygdala causes people to lose their ability to distinguish between friendly and threatening facial expressions. Additional factors play a major role in emotional responses, and one of those factors is how the brain expresses and recognizes facial expressions.
Emotions that are universal, such as happiness or anger, utilize distinctive muscles to express those emotions. This implies that the neurological system that makes this possible was part of human evolution, allowing nonverbal communication through facial signals and recognition of those signals to be valuable to hunting and survival techniques.
Located in the right cerebral hemisphere, this neurological system is not your only aid in the process of enabling you to express emotion. Variations in voice projection (pitch, tone, and stress), which are also controlled by a specific neurological system housed in the right cerebral hemisphere, make it possible for you to scream or laugh.