The Application of Positron Emission Tomography to the Study of Normal and Pathologic Emotions

This report reviews six studies in which positron emission tomography (PET) was used to investigatethe neuroanatomic correlates of emotion, anxiety, and anxiety disorders. PET was used to studybrain regions that participate in film- and recall-generated discrete emotions (happiness, sadness, anddisgust), picture-generated positive and negative emotions, and normal anticipatory anxiety; participatein the predisposition to, elicitation of, and treatment of panic attacks; participate in social phobicanxiety; and participate in specific phobic anxiety. Results of these investigations suggest that thalamicand medial prefrontal regions may participate in aspects of normal emotion unrelated to its type,valence, or stimulus; that modality-specific sensory association areas and anterior temporal lobe regionsappear to participate in the evaluation procedure that invests exteroceptive sensory informationwith emotional significance; that anterior insular regions appear to participate in the evaluation procedurethat invests potentially distressing cognitive and interoceptive sensory information with negativeemotional significance; and that anterior cingulate, cerebellar vermis, midbrain, and other brain regionsappear to participate in the elaboration of normal and pathologic forms of anxiety. As a complementto other research strategies, PET promises to help determine how multiple brain regions and themental operations to which they are related work in concert to produce emotions and how they conspireto produce emotional disorders.