Prefrontal cortex modulation of mood and emotionally induced facial expressions: A transcranial magnetic stimulation study

Repetitive transcranial magnetic stimulation (rTMS) can serve as a tool to experimentally test hypotheses of prefrontal cortex (PFC) modulation of emo tions. The present study used rTMS to test whether self-rated mood and emot ionally induced facial expressions are hemispherically lateralized dependin g on their valence, as indicated by previous studies. Healthy volunteers un derwent mood self-rating and computerized analysis of emotionally induced f acial expressions before and after rTMS of left or right PFC. Facial expres sion analysis revealed lateralized changes of facial expressions after rTMS , whereas changes of subjective mood ratings did not shaw a hemispheric lat eralization. On the basis of this study, the authors propose to combine rTM S and facial expression analysis for further studies of the cortical modula tion of emotions in humans.