Fear and panic in humans with bilateral amygdala damage

Decades of research have highlighted the amygdala's influential role in fear. We found that inhalation of 35% CO2 evoked not only fear, but also panic attacks, in three rare patients with bilateral amygdala damage. These results indicate that the amygdala is not required for fear and panic, and make an important distinction between fear triggered by external threats from the environment versus fear triggered internally by CO2.