OBJECTIVE: Happiness, sadness, and disgust are three emotions that
differ in their valence (positive or negative) and associated action
tendencies (approach or withdrawal). This study was designed to investigate
the neuroanatomical correlates of these discrete emotions. METHOD: Twelve
healthy female subjects were studied. Positron emission tomography and
[15O]H2O were used to measure regional brain activity. There were 12
conditions per subject: happiness, sadness, and disgust and three control
conditions, each induced by film and recall. Emotion and control tasks were
alternated throughout. Condition order was pseudo-randomized and
counterbalanced across subjects. Analyses focused on brain activity
patterns for each emotion when combining film and recall data. RESULTS:
Happiness, sadness, and disgust were each associated with increases in
activity in the thalamus and medial prefrontal cortex (Brodmann's area 9).
These three emotions were also associated with activation of anterior and
posterior temporal structures, primarily when induced by film. Recalled
sadness was associated with increased activation in the anterior insula.
Happiness was distinguished from sadness by greater activity in the
vicinity of ventral mesial frontal cortex. CONCLUSIONS: While this study
should be considered preliminary, it identifies regions of the brain that
participate in happiness, sadness, and disgust, regions that distinguish
between positive and negative emotions, and regions that depend on both the
elicitor and valence of emotion or their interaction.