| Reappraisal has been demonstrated to be an effective emotion regulation measure to cope with hard times in daily lives. It changes emotional responses through transforming the meaning of emotion-eliciting situations mentally. A model was proposed with respect to the neural bases of this strategy, pointing to the regulatory influences from cognitive control processes in prefrontal cortex (PFC) to emotion-related structures in limbic areas. In fact, increasing amount of imaging studies have being offering support to the model in the following decade. But in this study we focused not only on emotion regulation, but on the impacts of "resting" and "habitual usage" on emotion regulation.Both resting-state and task fMRI (functional magnetic resonance imaging) researches have revealed overlapping neural systems supporting emotion regulation (referring to "reappraisal" in the following text). Further, several studies have showed that resting connection between brain regions involved in emotion regulation and processing can be altered by preceding emotion-inducing stimulus. However, no study tries to answer how resting functional connectivity between PFC and limbic areas can make preparation for subsequent emotion regulation. This is of great significance as it is helpful to know more about the neural bases of emotion regulation and it can enrich our understanding of the complex "resting-functional" association. Further, anxiety is one of the major concerns of mental health showing abnormal neural systems supporting emotion regulation both during rest and in task. But to what extent anxiety will interface with this "resting-functional" association remains unknown with regard to emotion regulation. To this end, study one aimed to test whether functional connectivity within emotion regulation system at resting state can predict neural activity in the following emotion regulation task. Further, how this association can be modulated by trait anxiety was also of interest. In study two, we wanted to know whether habitual suppressor can reduce their negative feelings with cognitive reappraisal and its neural bases, as habitual suppression relates to difficulty in regulating emotion. In the present study, thirty-one participants differing in trait anxiety were directed to perform an emotion regulation task after an fMRI scanning lasting for 8 minutes, but two of them were discarded as they reported invalid data. This task asked them to either "Reduce" or "Maintain" their emotion produced by the upcoming aversive pictures; and then they rated their negative affection using a 4-point scale. Results showed that individuals with high-trait anxiety (HTA) can reduce their negative affection consciously as low-trait anxiety (LTA) do, exerting regulatory influences from dorsomedial PFC to insula. Moreover, it is interesting to find that resting dorsomedial PFC-insula coupling was able to predict their connection in the following emotion regulation task while ruling out the effect of depression, with a positive trend in high-trait anxiety while a negative trend in low-trait anxiety group. Further analysis showed that HTA group had lower dorsomedial PFC-insula connection at resting state while stronger connection in the emotion regulation task than LTA. Bases on the correspondence of human brain during activation and rest, It is supposed that resting frontolimbic connection may facilitate the recruitment of prefrontal cortex for regulating negative affection in high-trait anxiety. On the contrary, individuals with low anxiety are equipped with well functioning frontolimbic system. In this way, there is no need for them to pay much effort to control negative emotion in facing with aversive stimuli. This study differentiates the neural systems supporting emotion regulation in healthy individuals with different anxiety. Study two revealed that it is difficult for habitual suppressor to reduce negative affections through cognitive regulation. This may bring them into certain affective disorders. |
