While the amygdalae are probably most famous for their association with fear, I can't help but wonder about the enormous ripple effect that would occur if it were altered in various ways. Observations have been made, of course (monkeys and partial encephalectomies, a woman with lipoid proteinosis), but the emotions and behavior observed hold further implications: memory formation. The amygdala is crucial to evaluation of events' emotional significance, and also appears to be responsible for the influence of emotion on perception. It's the emotional arousal, not the importance of the information, that helps memory. Consider beta blockers--drugs that have an effect on anxiety, among other things--and their possible implementation for memory modulation.
Without the amygdalae--or with altered amygdalae--what would the hippocampus have to put into context and sequence during memory formation? Would traumatic experiences and repressed memories cease to exist? On a grander scale: how has the amygdala affected evolution? Facial expression recognition, art, poetry, all kinds of expression?