Researchers chose 120 passages from across all seven Harry Potter books . These passages were read by participants while in an fMRI scanner . Each was rated on how negative or positive , and how arousing they were . The researchers then compared the ratings of each passage to a control group that didn't have any knowledge about what had happened before reading it.
Researchers chose 120 passages from across all seven Harry Potter books . These passages were read by participants while in an fMRI scanner . Each was rated on how negative or positive , and how arousing they were . Scans revealed passages rated high for arousal activated parts of the brain associated with emotion , including the left amygdala .