Read this: More recently, scientists have started to focus on measuring changes in brain activity related to sexual arousal, by using brain-scanning techniques. A study on how heterosexual and homosexual men's brains react to seeing pictures of naked men and women has found that both hetero- and homosexual men react positively to seeing their preferred sex, using the same brain regions. The only significant group difference between these orientations was found in the amygdala, a brain region known to be involved in regulating fear.

What does the amygdala region of the brain do?
What is the answer? (If it cannot be answered, return "unanswerable")
known to be involved in regulating fear.