Regional brain responses to pleasant and unpleasant IAPS pictures: different networks.

PURPOSE

The purpose of this study was to investigate the brain circuitry involved in the processing of both positive and negative emotions in normal healthy subjects.

METHOD

we have recruited 15 healthy volunteers (9 males and 6 females, age range 30-60). In this block-design fMRI study, we compared the blood oxygen level dependant (BOLD) signal change as response to pleasant and unpleasant IAPS pictures, each compared to a neutral condition.

RESULTS

Pleasant pictures versus neutral condition contrast demonstrated significant activation (p(FDRcorrected) <0.05) in bilateral pre-frontal cortex (PFC), anterior and posterior cingulate gyri and temporal lobe. Unpleasant pictures relative to neutral condition exhibit significant activation (p(FDRcorrected) <0.05) in amygdala, hippocampus, parahippocampal gyri, temporal lobe, visual cortex, fusiform gyri, PFC and anterior cingulate gyrus.

CONCLUSION

Amygdala is mainly involved in the processing of negative emotions. Although an overlap in regions involved in the processing of pleasant and unpleasant IAPS pictures exists, the neural network for each is unique.