Learning to fear

Brain activity predicts when a fearful event will become a lasting fear memory, reports a study published online this week in Nature Neuroscience. This study may provide a basis for understanding how fear memories are strengthened and kept - a process that may go wrong in anxiety conditions such as post-traumatic stress disorder.

Merel Kindt and colleagues report that they can predict future fear memories by looking at patterns of brain activity during fearful experiences. During magnetic resonance brain imaging, participants saw pictures of faces and houses, some of which were followed by a small electric shock. Weeks later, people returned to the lab and the authors measured their fear responses to the pictures they had been previously seen. The authors report that this later fear memory was associated with more similarity in the patterns of brain activity when people looked at pictures shown with shocks, regardless of whether these were faces or houses. Those who had strong fear responses showed a greater similarity in their responses to the different images associated with shocks during the initial scanning session than those who had weak fear responses.