Brain Functional Basis Of Subjective Well-Being And Its Relationship With Emotional Processing

Since ancient times,happiness has always been the eternal pursuit of mankind.Happiness plays a positive influence on people's development.For example,happiness individuals are more creative than unhappy individuals,have more satisfied marriages and good interpersonal relationships.Everyone wants to be happy,but not everyone can get the same level of happiness.Subjective well-being(SWB)refers to the emotional and cognitive evaluation of an individual's quality of life.A large number of studies at home and abroad that have explored the factors affecting individual difference in SWB found that,a variety of cognition,motivation,and emotional processing processes(such as self-reflection and emotional regulation)are also related to individual difference in SWB,except for objective factors(such as age,gender,culture,education level,income level,etc.).The brain plays an important role in emergence and change of happiness.In recent years,with the development and maturity of neuroimaging technique,more and more researchers are beginning to examine the neural correlates of SWB.Existing researches have shown that SWB is closely related to the structure and function of the default mode network(DMN),frontal-parietal network(FPN)and salience network(SN).However,previous studies have mainly focused on structural magnetic resonance imaging(MRI)or resting-state functional MRI(fMRI),mostly focusing on the function of one or several single brain regions,and rarely examining the effects of interaction between multiple brain regions and even brain functional networks on individual differences in SWB.Contemporary neuroscience evidence has shown that many important psychological functions are not only located in one or a few separate brain regions,but rather require closely coordination and collaboration between multiple brain regions.Therefore,it is necessary to study the basis of brain function network connection of SWB.In addition,the brain itself is dynamic.With the continuous updating and advancement of neuroimaging data analysis methods,such as the application of dynamic functional network connectivity(dFNC),researchers can explore the relationship between brain dynamic characteristics and psychological behavior on a more subtle time scale.Therefore,combining the static and dynamic functional connectivity analysis to explore the brain functional basis of SWB is very helpful for comprehensive understanding of the neural mechanism of SWB.Moreover,the differences in the way of emotional processing are one of the important reasons for the individual differences in SWB.The negative emotional processing paradigm is the most commonly used method in the studies of the neural mechanism of SWB.In the past,most of the related research only focused on the results of local brain activation during emotional processing,and less on the characteristics of brain functional network connectivity in different levels of SWB in the process of emotional processing.Therefore,exploring the brain functional connectivity of different levels of SWB in the process of negative emotional processing can help to provide neuroscience evidence and theoretical gudience for the future practice of promoting SWB.The present study aimed to explore the relationship between individual differences in SWB and large-scale brain network dynamic connectivity patterns in resting-state and the brain activity patterns in negative emotional processing,starting from resting-fMRI and task-fMRI respectively.In the experiment 1,386 college students were recruited to participate in this experiment.All subjects completed the SWB questionnaire and resting-fMRI data acquisition.Firstly,static and dynamic functional connectivity analysis were performed on the resting-fMRI images,and then the static functional connectivity strength and the dFNC index were correlated with SWB score.The results showed that static functional connectivity between anterior DMN and SN is negatively correlated with SWB score.SWB score is negatively correlated with the fractional of time spent and the mean dwell time in state 4 in the brain dynamic process.SWB score is positively correlated with the number of transition between states.The state 4 is characterized by strong within-network connectivity(within the DMN and within the FPN)and weak cross-network connectivity(among the DMN,SN and FPN).The dFNC results were well replicated with different analysis parameters and further validated in an independent sample and all SWB-related states showed high similarity.These findings suggested that SWB is closely related to the dynamic interaction among DMN,FPN,and SN during resting-state fMRI.In the experiment 2,162 college students were recruited to complete an in-scanner negative emotional processing task and SWB questionnaire,which is same as the experiment 1.And then task-fMRI techniques were used to explore the differences in brain activity patterns between individuals with different levels of SWB during emotional processing process.Firstly,the differences in brain activation under emotional faces conditions and shape control conditions were compared from the local brain activation perspective.The results showed that the amygdala and the inferior frontal gyrus were more active under emotional face conditions than shape control conditions,which is consistent with previous studies.Then,multiple regression analysis was conducted on the differences in brain activity patterns between different task conditions and SWB score.The results found that the activities of right posterior cingulate cortex,left inferior temporal gyrus,and left angular gyrus were positively correlated with SWB score.Second,the brain functional network connectivity map(Power 264)was used to analyze the whole-brain functional connectivity patterns during task-fMRI.The first step was compared the differences in the whole-brain connectivity patterns between emotional face conditions and shape control conditions.The results found that compared with control conditions,functional connectivity between DMN and high-cognitive network or/and low-perception network was stronger while functional connectivity within DMN was weaker under emotional face condition.Then,multiple regression analysis was performed on the differences in brain network connectivity patterns between different task conditions and SWB score.The results showed that functional connectivity that are positively correlated with SWB score area mainly between DMN and high-cognitive network,between high-cognitive network and low-perception network while functional connectivity that are negatively correlated with SWB score are mainly within DMN and within low-perception network.These findings suggested that SWB is closely related to functional interaction between brain regions involved in self-reflection,executive control,emotional regulation,and reward processing during the process of negative emotional processing,revealing that individuals with high levels of SWB may be more proactive in using emotional regulation,behavioral inhibition,and reward processing skill to reduce negative emotional experiences.In summary,the experiment 1 and 2 all found that SWB is closely related to the dynamic functional connectivity patterns among DMN,control network,emotional salience network that are mainly involved in self-reflection processing,emotion regulation and executive control process from resting-state brain spontaneous activity and task-induced brain activity respectively,providing neuroimaging evidence for differences in SWB individuals in a variety of cognitive,motivational,and emotional processing processes.Additionally,the brain functional connectivity pattern was characterized by strong between-network connectivity and weak within-network connectivity,revealing that individuals with high-levels of SWB often exhibit more effective and flexible information exchange and communication between networks,which plays an important role in the application and practice of promoting individuals' SWB in future.