The Neural Mechanism Underlying The Relationship Between Memory Motivated Inhibition And Emotion Regulation

In our daily life,we often strived to forget painful memories,which benefited to maintaining a healthy emotional state and optimistic attitude,but also to improving our work efficiency.Similarly,In past studies,more and more experimental evidence has shown that people could suppress unpopular memories to weak memories.Researchers called these phenomena memory motivated inhibition.This effect of forgetting was known as the ability of memory inhibition.In order to study this ability in the laboratory,researchers designed two experimental paradigms:directed forgetting paradigm and memory inhibition paradigm.The capacity of emotion regulation is indispensable for mental and physical healthy.When faced with the stimulus that triggered negative emotion,individuals would employ a wide variety of emotion regulation strategies.Perhaps the most well studied strategy is cognitive reappraisal,which involves changing one's interpretations of affective stimuli in order to change or reduce their emotional impact.Compared with other regulation strategies,such as suppressing emotion expressive behavior,reappraisal was the most flexible and effective means of diminishing the negative impact of an aversive event.From previous studies,it can be found that emotions are mainly derived from internal information and external stimuli.The internal information mainly referred to the individual memory.For example,when people recalled the significant events with emotion in the past,the emotion could be restore or extend.External stimulation mainly referred to the stimulation that can affect individual emotion,such as meeting a rope in the forest would produce fear.The emotion was not only response to the stimulus itself,but also come from memories about stimulus(such as individual being bitten by a snake in the past).So,emotions,whether they're internal or external,were all about memory.lt follows that people may be able to regulate emotion by regulating their memories.Similarly,in the process of cognitive reappraisal,individuals often needed to suppress the original explanation(memory)of the stimulus before generating new adaptive explanation,so as to achieve the purpose of emotional regulation.It could be seen from the process that cognitive reappraisal involved memory motivated inhibition.Recently,Anderson(2018)integrated previous fMRI task states studies on memory motivated inhibition and cognitive reappraisal,and found that the process of memory motivated inhibition overlaps with part of the brain region during the process of cognitive reappraisal,indicating that memory motivated inhibition and cognitive reappraisal had similar neural basis.Although these evidences showed that memory motivated inhibition and emotional regulation were closely related,no studies directly explore the relationship.Therefore,it was necessary to study the relationship between memory motivated inhibition and emotional regulation.Therefore,this study intended to explore the relationship between memory motivated inhibition and emotional regulation from the perspective of behavioral and neural mechanisms through three studies.Study 1 focused on the behavioral relationship between memory motivated inhibition and emotional regulation.We collected the directed forgetting paradigm(DF),Emotion Regulation Questionnaire(ERQ)and demographic information as behavioral data for each participant,and explored the relationship between a memory motivated inhibition and emotional regulation.The results showed that there was a significant positive correlation between negative memory inhibition and cognitive reappraisal score,but no significant correlation between negative memory inhibition and expressive suppression;Meanwhile,no significant correlation between neutral memory inhibition score and expressive suppression and cognitive reappraisal score.At the same time,the regression analysis found that the ability of negative memory inhibition can significantly predict the cognitive reappraisal score.The results showed that the correlation between memory inhibition and emotional regulation was due to the significant correlation between negative memory inhibition and cognitive reappraisal.Therefore,in the following imaging analysis,we only focused on the neural basis of the relationship between negative memory inhibition and cognitive reappraisal in emotional regulation.The purpose of study 2 was to investigate the brain structural basis of the relationship between negative memory inhibition and cognitive reappraisal.Previous studies had suggested that the process of cognitive reappraisal involves the process of memory inhibition,and ability of memory inhibition contributed to the success of cognitive reappraisal.Therefore,in this study,we took negative memory inhibition as the independent variable and cognitive reappraisal as the dependent variable,focusing on the neural mechanism of the influence of negative memor inhibition on cognitive reappraisal.In this study,each subject scanned structural image.The brain regions related to the motivated inhibition of negative memory were obtained by calculating the correlation between the regional gray matter volume and the ability of negative memory inhibition.The structural basis of the influence of the negative memory inhibition on cognitive reappraisal was studied through the mediating effect analysis.The study found that the right middle frontal gyrus(rMFG)has significant positive correlation with the motivated inhibition of negative memory.The results suggested that negative memory inhibition plays a role in cognitive reappraisal through rMFG gray matter volume.The purpose of study 3 was to explore the functional basis of the relationship between inhibition of negative memory and cognitive reappraisal.In this study,the resting states functions imagine data were collected.The structural brain region rMFG obtained from the second study was used as the region of interest to make functional connectivity(FC)at the whole brain level.The correlation between the negative memory inhibition ability and the FC strength between rMFG and other brain regions was calculated.Finally through the mediating effect analysis to delve into the functions basis of negative memory inhibition effecting on cognitive reappraisal.The results showed that the FC strength of rMFG and four brain regions including the right insula was significantly positively correlated with the ability of negative memory inhibition.Interestingly only the strength of FC between rMFG and the right insula was also significantly positively correlated with cognitive rreappraisal scores.The mediating effect analysis showed that the FC strength between rMFG and right insula was part of the mediating factor between negative memory inhibition ability and cognitive reappraisal.The results of this study suggest that negative memory inhibition played a role in cognitive reappraisal through the FC between rMFG and the right insula.Combined with the three researches,it can be found that there is a positive correlation between the ability of negative memory inhibition and cognitive reappraisal in behavior.Negative memory inhibition affected cognitive reappraisal by rMFG gray matter volume and FC between rMFG and the right insula.These results suggests that the motivated memory inhabitation are significantly related to emotional regulation in behavior and neural mechanisms.This study not only directly prove the hypothesis of previous studies,but also deeply explored the neurologic evidence of the relationship.It provides a new perspective of memory motivated inhibitation to understand emotion regulation,and is of great significance to construct cognitive neural model of emotion regulation.