Neural Mechanism Of Enhanced Response Inhibition Capacity In Lovers

Romantic love manifests from an integration of behaviors,cognitions,and emotions associated with the desire to enter or maintain an intimate relationship with a specific person.Previous studies have shown that romantic love can improve individuals' mental ability,performances on vocabulary decision-making tasks,also can alleviate the negative effects of negative stimuli,and even relieve pain.Resting functional magnetic resonance imaging(f MRI)studies have shown that compared to single group,there is a significant increased functional connectivity of social cognitive networks in love group.This suggests that romantic love may enhance individuals' social cognitive control ability.Response inhibition means the suppression of inappropriate or unwanted behaviors that interfere with the behavior,cognitive,or social emotional goals that are currently desired to be achieved.Being able to change the automation of a particular situation in a timely manner and stop the ongoing response due to the momentary changes in the plan is an important feature of flexibility and adaptability.Emotion is one of the important factors that affect the ability of response inhibition.Emotional stop signal task(e SST)is one of the main paradigms to explore the interaction between emotion and response inhibition.Previous studies have shown that,compared to the successful suppression of neutral emotional facial stimulation,the stop signal reaction time(SSRT)of the successful suppression of neutral emotional facial stimulation is longer,that is,sad face emotional stimulation can damage individuals' ability of inhibition response.From the above discussion we know that romantic love can alleviate the impact of negative stimuli,and sad emotional face(also as a negative stimulus)can damage one's ability of response inhibition.Then,can romantic love alleviate the interference of emotional stimuli on the ability of response inhibition? In other words,compared with subjects in single group,do subjects in love group show a stronger ability of response inhibition in the condition of sad stimulation?Until now,there is no research exploring the interaction among romantic love,emotional information and response inhibition.Thus,this study used an e SST task combined with the functional magnetic resonance imaging technique to explore the performance and neural mechanism of response inhibition in the presence of sad stimulationIn study one,we use emotional stop signal task to examine the impact of romantic love on the ability of response inhibition of sad stimulation.The material of the experiment contains 40 pictures of sad faces(20 male and 20 female)and 40 of the neutral face(20 male and 20 female)which was selected from the Chinese Affective Picture System.A total of 88 undergraduate students in the Southwest University were enrolled,including 44 in love group(21 female and 23 male),44 in single group(19 female and 25 male),to perform the e SST task.The within-group variable is emotional type of face(sad Vs.neutral),the between-group variable is the condition of love(love group vs.the single group),the dependent variable is the stop signal response reaction(SSRT)and the go signal reaction time(Go RT).The results showed that SSRT in the love group was significantly lower than that in the single group during sadness-related trials,and there was no significant difference in SSRT between the two groups during the neutral trials.No matter in the condition of sad or neutral stimulation,there is no significant difference of Go RT between the two groups.Furthermore,we divided the love group into two subgroups: early stage love(from 1 to 8 months,N=23)and longer periods love(from 9 to 18 months,N=20).Exploring the effect of different stage of love relationship,we found SSRT of lovers in early periods group was shorter than that in longer periods group and single group,but no significant difference was found between the latter two groups.The study showed that romantic love could improve the ability to inhibit the response to sadness-related stimuli,which is mainly appeared in the early stages of love.In study two: we use emotional stop signal task to examine the neural mechanism of the impact of romantic love on the inhibitory ability to sadness-related stimuli.40 undergraduates participated in this experiment(love group: 23 people;single group: 17 people).The experimental design is similar to study one.After the whole brain activation analysis,we found that,compared to neutral stimuli,sadness-related inhibitory control significantly increase the brain activations areas as follows: right caudate nucleus,right dorsolateral prefrontal cortex(DLPFC),right medial superior frontal gyrus(extending to right anterior cingulate cortex,ACC),right medial orbitofrontal cortex(m OFC)and so on.Between group analysis suggests that compared to single group,during sadness-related trials,love group reveal significant increase brain activations areas which are related to inhibitory control(such as left inferior frontal gyrus,IFG),also conclude left amygdala,left parahippocampal gyrus,left hippocampal and so on.Study three: using psychophysiological interactions(PPI)to study the differences between lovers and singles on different valence related brain functional connectivity.We select two brain activations(right dorsolateral prefrontal cortex)which are related to inhibitory control in study two.The results suggest that during different emotional valance inhibitory control progress,compared to single group,love group show a significant increase intense functional connection: between right dorsolateral prefrontal cortex and right left inferior frontal gyrus,between right dorsolateral prefrontal cortex and right pre-supplementary motor area.This study draws the following conclusions:(1)Under the condition of sadness,romantic love could improve individual response inhibitory ability.Specifically,on the performance of the emotional Stop signal task(e SST),under the condition of the sadness-related Stop signal,the SSRT of the love group is significantly lower than that of the single group,which means an improved response inhibitory capacity,this improvement effect mainly appeared in the early stages of love.(2)Under the condition of sadness,romantic love could enhance activating brain areas which are related to inhibitory control(such as IFG)or emotion regulation(such as amygdala),the improved inhibitory capacity in lovers maybe related to activities of these brain areas.(3)Under the condition of sadness,romantic love lead to increased levels of functional connectivity in inhibitory control related brain regions(between right dorsolateral prefrontal cortex and right left inferior frontal gyrus,between right dorsolateral prefrontal cortex and right pre-supplementary motor area).The increased functional connectivity in these brain areas may enhance response inhibitory capacity in lovers.