Where the Past Begins: Memory and Imagination

by Amy Tan

process that is significant to me as a writer: in heightened situations, the vagus nerve releases a hormone, norepinephrine, into the part of the brain known as the amygdala, where the strongest emotional memories and their original reactions are stored. The more fearful the experience the greater the surge of norepinephrine into the amygdala, and that increases the amygdala’s ability to store vivid, more strongly felt, lasting memories. They are called visceral reactions for a reason: the viscera react subconsciously when memory of the traumatic moment rises, often unexpectedly. For assault victims, the popped balloon instantly brings back the moment they were shot. This is not where you’ll find happy memories of birthday parties or trips to the zoo—unless the birthday cake exploded and the lion escaped the cage and ate your ear. In the amygdala reside the horror stories of our lives: the worst experiences we’ve had. This is memory lane for people with post-traumatic stress disorder.