Psyc 1001
Brain Mechanisms of Fear Extinction: Historical Perspectives on the Contribution of Prefrontal Cortex
Francisco Sotres-Bayon, Christopher K. Cain, and Joseph E. LeDoux
What brain regions are involved in regulating behavior when the emotional consequence of a stimulus changes from harmful to harmless? One way to address this question is to study the neural mechanisms underlying extinction of Pavlovian fear conditioning, an important form of emotional regulation that has direct relevance to the treatment of human fear and anxiety disorders. In fear extinction, the capacity of a conditioned stimulus to elicit fear is gradually reduced by repeatedly presenting it in the absence of any aversive consequence. In recent years there has been a dramatic increase in research on the brain mechanisms of fear extinction. One region that has received considerable attention as a component of the brain’s extinction circuitry is the medial prefrontal cortex (mPFC). In the present article, we review the historical foundations of the modern notion that the mPFC plays a critical role in emotional regulation, a literature that was largely responsible for studies that explored the role of the mPFC in fear extinction. We also consider the role of the mPFC in a broader neural circuit for extinction that includes the amygdala and hippocampus. Key Words: Emotion, conditioning, history, amygdala, hippocampus, exposure therapy over, a major approach to the treatment of emotional disorders involves the promotion of extinction (Barlow 2002; Craske 1999; Foa and Jaycox 1999; Wolpe 1968). Elucidation of the extinction process and how the brain mediates this process could thus lead to better understanding of, and therapies for, emotional disorders. In this introductory article, we will briefly discuss the nature of extinction and then consider the historical origins of contemporary work on the brain mechanisms of extinction. We concentrate on extinction of learned fear, because much of the recent
Francisco Sotres-Bayon, Christopher K. Cain, and Joseph E. LeDoux
What brain regions are involved in regulating behavior when the emotional consequence of a stimulus changes from harmful to harmless? One way to address this question is to study the neural mechanisms underlying extinction of Pavlovian fear conditioning, an important form of emotional regulation that has direct relevance to the treatment of human fear and anxiety disorders. In fear extinction, the capacity of a conditioned stimulus to elicit fear is gradually reduced by repeatedly presenting it in the absence of any aversive consequence. In recent years there has been a dramatic increase in research on the brain mechanisms of fear extinction. One region that has received considerable attention as a component of the brain’s extinction circuitry is the medial prefrontal cortex (mPFC). In the present article, we review the historical foundations of the modern notion that the mPFC plays a critical role in emotional regulation, a literature that was largely responsible for studies that explored the role of the mPFC in fear extinction. We also consider the role of the mPFC in a broader neural circuit for extinction that includes the amygdala and hippocampus. Key Words: Emotion, conditioning, history, amygdala, hippocampus, exposure therapy over, a major approach to the treatment of emotional disorders involves the promotion of extinction (Barlow 2002; Craske 1999; Foa and Jaycox 1999; Wolpe 1968). Elucidation of the extinction process and how the brain mediates this process could thus lead to better understanding of, and therapies for, emotional disorders. In this introductory article, we will briefly discuss the nature of extinction and then consider the historical origins of contemporary work on the brain mechanisms of extinction. We concentrate on extinction of learned fear, because much of the recent