Studying screams of terror, David Poeppel of New York University and colleagues have concluded that human screams of terror produce a sound that is unlike any other made by humans, and contains properties that are not found in any other type of human speech: male or female, adult or child. Using fMRI, they found that screams that were rougher more effectively activated the amygdala, which contains the brain’s fear circuits. By comparison, most other sounds tend to activate only the auditory cortex of the brain, at least initially. In addition, people seem to report the direction from which a scream originated more accurately than other non-terror sounds. The researchers theorize that the brain is uniquely tuned to screams. These unique properties may explain how our brains recognize and react to a scream so quickly, and could help develop a new generation of alarm systems, for one thing.