Emotions are incredibly complex; there one of the fundamental parts of our humanity – everyone experiences them every day – yet scientists know surprisingly little about them. A big reason for this is that the brain is so incredibly complex. A hundred billion neurons firing every minute is quite a bit, and it’s difficult – to say the least – to measure all of that activity in real time. However, there are collections of neurons in the brain – nuclei – that both relate to different types of emotions and are large enough to be removed, either accidentally or through noninvasive magnetic impulses.
One of these is the amygdala, the main control center for fear response. Fear is the oldest emotion; it’s helped keep our species alive for millennia by directing us away from harmful situations, and it makes sense that it would have its own dedicated area of the brain. When the amygdala is removed, animals, including humans, show a remarkable reduction in fear response. There’s one example I remember of a women who had her amygdala removed because of a tumor: she was walking home late at night when a man pulled a gun on her and asked for all her money. Because she didn’t have any fear response, she just walked right up to him and slapped him; he was so unnerved that he ran away.