2010 Volume 28 Issue 1 Pages 17-27
It is widely believed that the amygdala plays the central role for emotion processing. However, most evidences have been derived from fearful stimuli, and there have been less evidence that the amygdala respond to other emotions particularly to positive emotions such as happiness. To investigate whether the amygdala plays the central role for emotion processing in general, 10 right-handed healthy participants (2 males and 8 females, 24.5±2.1years old) were passively shown morphed dynamic emotional facial expressions (happiness, anger, sadness, and neutral) while they were scanned on an event-related fMRI. Whole-brain fMRI results revealed greater activation within the right amygdala, left globus-pallidus, and medial prefrontal cortex during viewing both angry and happy faces compared with the neutral face. However, these activations were not observed during viewing sad face. These results suggest that the amygdala plays the central role in processing not only negative but also positive emotions and that the amygdala is not activated by threat signals as has often been suggested. More detailed investigation will be necessary for sad emotion.
