ABSTRACT

Living in a complex and dangerous world requires us to respond when met with a challenge. The term arousal is used in different ways, often to mean increasing alertness or an emotional reaction. When faced with a predator, for example, an animal reacts physically and mentally to deal with it appropriately, either fighting or escaping. Although humans living in civilization may face such threats less often than our distant ancestors, the arousal machinery of the brain is still in place. Ironically, a physical and mental reaction that evolved to prepare us for an attacking lion is the same response elicited by a college exam. Still, the arousal reaction is appropriate in some situations. But as with many disorders of the mind and brain, a normal and adaptive reaction can be overactivated and become maladaptive. Over-activation of our arousal mechanisms can result in anxiety and insomnia.