The ability to simultaneously acquire objective physiological measures of emotion concurrent with fMRI holds the promise to enhance our understanding of the biological bases of affect and thus improve our knowledge of the neural circuitry underlying psychiatric disorders. However, the vast majority of neuroimaging studies to date examining emotion have not anchored the examination of emotion-responding circuitry to objective measures of emotional processing. To that end, we acquired EMG activity of a valence-sensitive facial muscle involved in the frowning response (corrugator muscle) concurrent with fMRI while twenty-six human participants viewed negative and neutral images. Trial-by-trial increases in corrugator EMG activity to negative pictures were associated with greater amygdala activity and a concurrent decrease in ventromedial PFC activity. Thus, this study highlights the reciprocal relation between amygdalar and ventromedial PFC in the encoding of emotional valence as reflected by facial expression.

Although the co-occurrence of negative affect and pain is well recognized, the mechanism underlying their association is unclear. To examine whether a common self-regulatory ability impacts the experience of both emotion and pain, we integrated neuroimaging, behavioral, and physiological measures obtained from three assessments separated by substantial temporal intervals. Our results demonstrated that individual differences in emotion regulation ability, as indexed by an objective measure of emotional state, corrugator electromyography, predicted self-reported success while regulating pain. In both emotion and pain paradigms, the amygdala reflected regulatory success. Notably, we found that greater emotion regulation success was associated with greater change of amygdalar activity following pain regulation. Furthermore, individual differences in degree of amygdalar change following emotion regulation were a strong predictor of pain regulation success, as well as of the degree of amygdalar engagement following pain regulation. These findings suggest that common individual differences in emotion and pain regulatory success are reflected in a neural structure known to contribute to appraisal processes.