Like other animals, humans learn to fear harmful events, such as being attacked by a dog. But the ability to learn fear in the absence of direct experience — for example, by being told a story about a neighbour who has been attacked by a dog — is distinctively human. Fear causes more blood to flow to the amygdala, a small almond-shaped structure located deep in the cortex of the brain. In the April
Phelps et al examined activity in the human amygdala using functional magnetic resonance imaging in combination with a task called instructed fear. Subjects were presented different coloured boxes and told that they may receive an electric shock when a particular colour was presented. They were told to expect no more ...
