Social Intervention For Renewal Of Fear Memory

Post-traumatic stress disorder refers to a mental disorder that persists after an individual experiences or suffers a major traumatic event.The patient presented with an influx of fear memory associated with traumatic events,persistent nightmares,and abnormal alertness of high alertness.Exposure therapy is an effective therapy for the treatment of post-traumatic stress disorder,but this therapy does not completely erase the patient's fear memory,but instead forms a new recall memory during the treatment.Memory and fear memory exist at the same time and in the patient's memory structure.When the external event context changes,the patient's fear memory is easy to reproduce again.Therefore,finding a way to suppress the renewal of fear memory is of great significance for the treatment of patients with post-traumatic stress disorder.In recent years,foreign psychotherapy requires PTSD patients and family members to participate in some exercises during treatment(some using cognitive exposure therapy and requiring family participation,and some only requiring family and patients to complete specific exercises),and the treatment effect can make the patient's symptoms(such as traumatic memory flashback)are effectively improved.Therefore,we believe that the social support presented during treatment may have an inhibitory effect on the recurrence of fear of the patient,but at what time it actually worked,the previous study did not give us a hint.Considering that the fear memory renewal of animal model-analogue anxiety disorders has been widely recognized,this study used an animal model to study this issue and to explore the stage at which social support was shown to have the greatest impact on fear renewal.The present thesis mainly includes four parts as follows:The first part is literature review.First,it reviews,summarizes,and sorts out the features of fear memory formation,extinction,and renewal.Then,we searched for evidence that a large number of social company suppression of fear responses,and proposed the assumption that social company have an impact on fear renewal.Finally,it summarizes the limitations of previous studies and the theoretical and practical significance of this study.The second part is the main part of the paper,including two empirical studies.The animal model was used to simulate the fear memory renewal of patients with anxiety disorder.It included three stages:the fear memory acquisition stage(pairing with conditional stimulus and unconditional stimulus:CS-US),and the fear memory extinction stage(present of conditioned stimuli but not paired with unconditioned stimuli:CS-no US)and test Phase(only present of conditional stimulus:CS).The ABC model is a classic model of fear renewal:A represents the context of the fear acquisition phase,B represents the context of the fear extinction phase,and C represents the context of the test phase(the capital letter denotes the context one receives fear acquisition,extinction,and testing,respectively).The ACC is the control model.When the extinction context is the same as the test context,the rat would retrieve extinction memory during testing(CS-no US),and the fear memory does not reappear.The ABC model is a standard renewal model.When the test context and the extinction context are different,the rat would retrieve the fear memory(CS-US)during testing,and the fear memory will renew.The ABC paradigm needs to be compared with the ACC paradigm to show that the ABC paradigm does induce fear renewal.Considering that the renewal of the fear memory is in the test phase,in the first experiment,the rats are presented in the test phase of the ABC and ACC models with companion and without.Based on the prediction that the ABC model will induce more fears than the ACC model,we hypothesize the fear level of rat with companion is significantly lower than that rat without,that is,companion during the test phase can directly inhibit the fear renewal of rat.Considering that the context outside the extinction context is ever-changing,the rat leaves the extinction context would face the strange environment alone and its fearful memory would appear again.If social support is given during the extinction phase,the rat can be allowed to face alone the strange environment(that is,the fear of renewal is suppressed),this study is very meaningful.It is impossible that patients' relatives and friends would always around them when the patients with anxiety disorder leave the treatment environment,patients need to face a variety of strange life in the future life.Taking into account the above realities,therefore,in the second experiment,present of companion in the extinction phase of the ABC and ACC models,the test phase was the same as in Experiment 1,and predicting that the presence of partner in the extinction period could inhibit the renewal of fear in rats.The third part is the data of this study.In Experiment 1,the fear level of the four groups of rats in the fear acquisition phase was only affected by the number of electric shocks(F(3,72)=67.82;p<.001;?p2=.739).After two days of extinction,the fear level of the experimental rats was significantly reduced(F(1,24)=34.46;p<.001;?p2 =.58).The rest were not significant,ensuring that the level of fear in rats is similar before entering renewal test.Rats with a companion during baseline of test were more active than unaccompanied rats(F(1,24)=9.6;p<.05;?p2 =.285).Test Phase:2(context:ACC/ABC)*2(Accompanying:With/without partner at the Test Stage)*3(Test Block:First/Second/Third Block)Repeated Measures Variance Analysis shows main effects of the context(F(1,24)=9.16;p<.01;?p2=.28),the main effects of test blocks were significant(F(2,48)=9.20;p<.001;?p2=.28),the interaction between the context and the test block was significant(F(2,48)=9.33;p<.001;?p2=.28).Further analysis found that the rat in the ABC model than the rat in ACC model showed higher fear levels from the first to the last block(all P<.05),and the first block had the greatest difference in fear levels(p<.01).This result shows that the ABC model has produced a strong renewal effect in rat,and more importantly,the interaction between companionship and context is significant(F(1,24)=5.42;p<.05;?p2=.20).The analysis showed that there was no significant difference between the companied rats and the unaccompanied rats in the ACC model(p=.74);while in the ABC model,rats with partner showed a lower level of fear than unaccompanied rats(p=.002).Experiment 2,the fear level of the four groups of rats in the fear acquisition phase was only affected by the number of electric shocks(F(3,60)=1 14.60;p<.001;?p2 =.85).After two days of extinction,the fear level of the experimental rats was significantly reduced(F(1,20)=13.92;p<.001;?p2 =.41).There was no difference in the active levels of all the experimental rats at baseline(F(1,20)=.15;p=.69).Test Phase:2(Context:ACC/ABC)*2(Accompany:with/without partner at the test stage)*3(Test Block:First/Second/Third Block)Repeated Measures Variance Analysis shows main effects of the accompany(F(1,20)=4.428;p<.05;?p2=.18).The main effect of the test block(F(2,40)=7.14;p<.05;?p2 =.26)and the interactions between the companion and test blocks were significant(F(2,40)=4.7;p=.025;?p2=.19).Further analysis revealed that the companioned rats had significantly lower fear levels than unaccompanied rat.The difference between the companied rats and the unaccompanied rats in the first block was the largest(p=.01).The main effect of the context was not significant(F(1,20)=.001;p=.97)The interactions between context and companion were not significant(F(1,20)=.02;p=.89),and the interactions between accompany,context,and test block were not significant(F(2,40)=.50.p=.56),indicating that companionship during the extinction phase may have an impact on fear,leading to insignificant main effects on both ACC and ABC context.However,although there was no difference in the level of fear in the rat tested in the ACC and ABC models,the level of fear was slightly higher.In order to rule out the removal of the partner during the test phase,the fear of the ACC model may be renew,so comparing experiment 2 and experimental ACC model without partner during test phase,it was found that there was no difference between the two group(t)=-1.48,p= 183.The discussion and conclusion constitute the last fourth part.This section explains the results of the study and draws the following conclusions:First,the ABC model successfully induced the fear renewal of the rat,and presence of the companion in the test stage can directly suppress the rat's fear renewal.If the test context is same as extinction context(ACC model),Whether or not a companion is presented,the level of fear in rats during the test phase was low and similar.Second,the extinction stage presence of company in the ABC model shows a weak inhibitory effect on the renewal of fear memory when testing rat alone.When the rats are alone in the ABC model and the ACC model during the testing phase,there was no difference in fear levels,but the fear levels were slightly higher.Third,the effect of social buffering during extinction and testing two stage yield the same inhibition effect as social buffering only during testing.Fourth,the clinical meaning of the study.According to practical situation of patients,requiring the patient's family members to help patients for completing the extinction training or cognitive training,etc.By presence of family members,spouses or friends to patient during the treatment could induce the effect of social buffering,but the inhibitory effect of social buffering is weak.It is a crucial stage to obtain social buffering in fear memory renewal when patients leave the treatment context.That is to say,it is important to establish a strong social support system for patients to recover after treatment completed.