Temporal dynamics of emotion regulation : a fMRI study of neural activity and functional connectivity

Emotion regulation strategies are thought to have differential impact on emotional experience as a consequence of when and how they interact with the emotion-generative process. These differences are thought to be reflected in the dynamics of the neural systems underlying emotion generation and emotion regulation. However, few studies of neural activity have hitherto been undertaken directly contrasting different emotion regulations strategies, and none have investigated the temporal dynamics of connectivity in emotion regulation. Therefore, the current study investigated the temporal dynamics of neural activity and functional connectivity during performance of cognitive reappraisal and expressive suppression. These strategies are thought to differ in when in the emotion generative process they are active. These differences are hypothezised be reflected in different temporal signatures and neural substrates. To investigate this 39 subjects of both genders underwent fMRI scanning while regulating their emotional response to 15 second disgust-inducing film clips using these strategies. Contrary to earlier findings, the current study found suppression- and reappraisal-related activity in both Early (0-5) and Late (10-15) periods of the film. The results concur with previous studies in indicating that Reappraisal is subserved by two distinct top-down appraisal systems, that affect the both perceptual and affective bottom-up appraisal systems. Suppression in turn was indicated to be two distinct networks, one motor control network and one conflict monitoring network hypothezised to be involved in mediating the conflict between the inhibitory motor control and prepotent emotional response patterns. The temporal dynamics and connectivity patterns were interpreted as supportive of this hypothesis. Further evidence was found that both of these strategies are characterized by activity in a region of the brain implicated in emotion-related control in a wide variety of studies. This is interpreted as evidence for the existence of a core emotion regulation network centred on the Inferior Frontal Gyrus, that affords emotion- related regulation through the setting of reference states for other, task-specific, control networks