AU2019101169A4 - Method of TMS for Extinction about Early Traumatic Memory - Google Patents

Abstract

Abstract: Individuals will experience strong traumatic memories after traumatic events such as earthquakes, car accidents, or loss of loved ones, the most common of which is fear memory. In this experiment, a multi-sensory compound stimulation model (electric stimulation + picture) was used as the conditional stimulus, and the skin electrical response was used as the index of fear response. The effect of retrieval-extinction paradigm on the conditional fear extinction was tested. In addition, high-frequency rTMS was introduced as a treatment.To explore the therapeutic effect of TMS on conditional fear, with the aim of providing new measures for the treatment of PTSD. Preparallon A Study of 77ranscraiaI Mim Ret i c St i iulati Ur (TMS for Khoul 7rasurnaic ZM1eowy on Orne 'sEarly stage A Extinction andForgetting of Fear Memoey B Spontaneous recovery acquisition extinction remantest acquiston extinction remain test Gxt fro I mmed 2hrs 24 hrs C RA)WW B Rebulding acquisition extinction remantest (C*UtexA) (ContextB) acquisition extinction remantest CD (I)9I ContetA Contxt B UfteIn Ufein Context Figure1I

Description

Method of TMS for Extinction about Early Traumatic Memory

FIELD OF THE INVENTION

Individuals will experience strong traumatic memories after traumatic events such as earthquakes, car accidents, or loss of loved ones, the most common of which is fear memory. In this experiment, a multi-sensory compound stimulation model (electric stimulation + picture) was used as the conditional stimulus, and the skin electrical response was used as the index of fear response.

BACKGROUND

Traumatic (fear) memory is defined as a memory that causes the individual's mental, emotional, cognitive and physiological abnormalities, and it is the core memory type of PTSD (Post-traumatic stress disorder) carries when it damages individuals' psychological and cognitive functions. PTSD or traumatic memory is a psychiatric disorder that can occur in people who have experienced or witnessed a traumatic event such as a natural disaster, a severe accident, a terrorist act, war/combat, rape or other violent personal assault. One general PTSD interpretation model based on Bapulov's classical conditioning theory described traumatic memory as a conditional fear memory. Other essays acclaimed traumatic memory affects individual memory, attention and neurophysiological mechanisms, etc. Among them, the abnormal

2019101169 11 Oct2019 processing of memory is most prominent, as shown by intrusive memory (perforation) and blank memory. Flashback, an inescapable memory, refers to the wounded events vividly break into the patient's mind, inescapable memory. Characterized by repeated, unavoidable traumatic experiences, those stimulate associated with traumatic events (triggered) can cause the patient to experience the pain of trauma again, accompanied by increased alertness, such as nightmares, panic reactions, and lack of concentration. Blank memory is characterized by memory avoidance, memory incoherence, and selective forgetting, i.e., the inability to recall details related to injury events. Brain regions associated with fear memory retrieval are as follow. The amygdala is an essential brain region for the formation of regressive memory. The formation and regression of fear memory depends on the involvement of the amygdala, but this does not mean that the regression will erase the fear. Memory traces on the amygdala. The ventromedial prefrontal cortex (vmPFC) is considered to be the key brain region for emotional response inhibition, and is also involved in decision-making, self-control, and moral judgment. vmPFC plays an important role in the process of individuals controlling and regulating their emotional responses according to specific social contexts; individuals with ventral medial prefrontal lobe defects in early development may exhibit antisocial behavior and moral judgment functional impairment in adulthood ( Boes et al., 2011). The

2019101169 11 Oct2019 hippocampus is associated with the vmPFC and the amygdala, and serves as a task to regulate the expression of fear, and the situation is important for the fear to subside, while the hippocampus is associated with conditional fear involving environmental cues.

Transcranial magnetic stimulation, TMS, is a type of mental stimulation that uses an attractive field to cause electric flow at a specific area of one's brain. TMS was at first used to explore nerve conduction, and a device for brain mapping, as a test for neuronal systems, and as a modulator of brain function. Clinically, brain stimulation has been found to improve the side effects of depression. However, because of the multifactorial idea of the intercession, the general viability of TMS for the treatment of depression stays unclear. In any case, TMS is still early in its development; however, since being FDA-cleared (Food and Drug Administration-cleared) for Significant Misery in 2008 in the U.S. has turned into a standard treatment while it is being refined. Concentrates, for example, this one which explores TMS reaction and indicators will direct future clinical practice, and permit the interpretation of neuroscience investigation into treatment conventions which target systems associated with wretchedness, PTSD and different conditions. There are some research is finding the use of TMS to be beneficial with individuals dealing with substance abuse disorders as well as with some of the symptoms of pervasive developmental disorders like Asperger's or

2019101169 11 Oct2019 autism. Indeed, even less outstanding is the adequacy and viability of TMS for the treatment of PTSD and GAD (Generalized Anxiety Disorder). Different roads for TMS improvement incorporate utilizing various examples of attractive heartbeats, utilizing various kinds of attractive loops to achieve further zones of the mind, consolidating TMS with different ways to deal with prime for better reactions, and treating numerous cerebrum locales for a more prominent effect to profit treatment-safe patients and those near them.TMS may turn into a favored option for extreme treatment safe conditions; however, right now, it is a promising remedial device with moderate adequacy tantamount to drugs and psychotherapy. Treating sorrow and PTSD stays testing, and commonly includes a multifaceted treatment plan.

The current mainstay of treatment for PTSD relies on psychopharmacological and trauma-focused psychological interventions. These interventions are useful, but some patients fail to respond. There are recent studies that aim to facilitate exposure-based psychological treatments applying means such as virtual reality or the partial NMDA agonist D-cycloserine. The broadly accepted neurobiological model for PTSD considers it as a stress-induced fear circuitry disorder. The ability to achieve and preserve the extinction of the acquired fear response is severed due to functional impairment in the medial prefrontal cortex (mPFC) control over the amygdala. This model has been corroborated by

2019101169 11 Oct2019 numerous animal and human studies, although challenged by some. Medial PFC hypo-activation is inversely correlated with amygdalar hyperactivation in PTSD patients versus trauma-exposed controls. mPFC activation was also found to be negatively correlated with PTSD symptom severity, while successful treatment has been associated with increased mPFC activation. One possible way to try and amend this mPFC hypo-activation is Transcranial Magnetic Stimulation (TMS). TMS enables non-invasive modulation of brain activity. In October 2008 the FDA approved TMS for the treatment of Major depression, following a pivotal study by O'Reardon et al. While in depression TMS has been widely utilized in clinical studies for almost two decades and recently also in regular clinics, very few studies of TMS in PTSD patients were published thus far. We tested the hypothesis that high frequency (excitatory) stimulation of the mPFC could facilitate extinction of the fear response to the traumatic memory.

SUMMARY

There are three primary stages for finishing the whole experiment as figure 1 shown, including the first stage — preparation, the core procedure followed by — formal experiment and the final stage — data analysis.

In the preparation stage, the first step is to measure the motor threshold (MT), during which the operator locates a precise brain region controlling

2019101169 11 Oct2019 hand movements by using a treatment cap and the TMS. Then, the magnetic stimulation should be adjusted at an appropriate level before a series of procedures to acquire the subjects’ threshold. Simultaneously, the emotional valuation of fifteen images from the internet has to be done, resulting in two neutral images of them that are most applicable to the assessment standard are chosen. According to the PAD three-dimensional emotion theory, the judgment of images requires three primary scales, including Pleasure-Displeasure Scale, Arousal-Nonarousal Scale and Dominance-Submissiveness Scale. Eventually, one showing a school scene serving as a simulated scene of school bullying, while the other displays a scenery without information about school or bullying.

After that, the formal experiment should be performed, which comprises six procedures: habituation, pain intensity rating, fear acquisition, fear extinction, TMS treatment and fear retrieval. Noticing that only fear retrieval procedure should be conducted the next day, and each subject is announced and ensured to complete the other five procedures on one day. Equipments: the Biopac 16-channel physiological recorder was necessary during the whole experiment; The Biopac electrostimulator was necessary during the Electric shock intensity assessment stage? Transcranial magnetic stimulation therapy instrument was during the TMS treatment phase.

2019101169 11 Oct2019

Habituation is a procedure in order to eliminate fear interference, ensuring that subjects don’t have fear response to experiment materials and process spontaneously. At the beginning, subjects were asked to stick the electrode pastes on their left fingers and right arm, linking to the machines. They then followed the instruction to scan the computer screen showing the selected photos.

Next follows the pain intensity rating. Subjects received electrical stimulation from weak to strong in a safe range and finally determined the maximum endurance level- unpleasant but not painful- used for fear simulation in the following phases.

After pain intensity rating, subjects started fear acquisition. In this phase, two different contexts were used, provided by photos mentioned above, presented on the computer screen. In each trial, one of the contextsselected randomly- was presented alone for four seconds. Duration of inter-trial intervals varied randomly between four to eight seconds, during which a black screen with a white fixation cross was shown. The electrical stimulation took place randomly in the context in which the photo of campus was shown (context A), simulating the scene of school violence for subjects to learn.

The phase of fear extinction started 10 minutes after, aiming for eliminating the association between context A and the electrical stimulation, namely the fear of school violence. In each trial, one of the

2019101169 11 Oct2019 contexts- selected randomly- was presented alone for four seconds, and the duration of inter-trial intervals varied randomly between four to eight seconds, the same as the last phase. The only difference was that there was no electrical stimulation.

The time when fear extinction finished, subjects were asked to do TMS treatment, which might help eliminate fear. Subjects were divided into two groups, without their awareness. In group one, subjects didn’t receive TMS treatment. Meanwhile in the other group, F4 brain regions were first located by calculating subjects’ head informations, including lengths from tragus to tragus, from nasion to inion and head circumference, measured by tape. And then we used the incontinuous theta burst stimulation (iTBS) mode for treatment, with 70 percent of subjects’ threshold, the treatment coil placed on the F4 brain region. Comparing two groups of results later in the fear retrieval phase, we will understand what role TMS plays in fear extinction.

hours later came the recall phase, whose result illustrate the return of fear. The process was exactly the same as the extinction phase. After the formal experiment stage, skin conductance responses (SCRs) were regarded as the raw data importing in MATFAB in order to do data analysis. A series of histograms and trends showing t-Test results of paired two sample for means are achieved, which were compared within each phase and inter-phases.

2019101169 11 Oct2019

DESCRIPTION OF THE DRAWINGS

Figure 1 shown, including the first stage — preparation;

Figure 2-7 shown a compares the behavior characteristics after retreat and forgetfulness, b, C, and D, respectively, represent the behavioral characteristics of spontaneous recovery, renewal, and reconstruction after subsidence.

DESCRIPTION OF PREFERRED EMBODIMENT

The theoretical model of conditional fear and its traditional exit training model

The theoretical model of conditional fear is based on Pavlov condition reflection and is one of the most important animal models to explore the processes of fear acquisition, storage, extraction, and retreat, as well as the cognitive neural mechanisms in these processes. In this model, multiple aversion stimuli (unconditional stimulation, unconditioned stimulus, US) and neutral stimulation (CS) are performed on the animals, after which conditional stimulation can trigger a fear response. However, if this condition stimulus is repeatedly presented individually and does not match the non-conditional stimulation (CS-noUS), the previously acquired response to CS fear will gradually weaken, or even disappear, this is known as the traditional retreating training mode. Traditional retreat training models are clinically an effective coping strategy for traumatic stress disorder, but in many cases, this acquired conditional fear

2019101169 11 Oct2019 response is often re-induced, showing the characteristics of spontaneous recovery, renewal, reconstruction and other fear recurrence behavior characteristics (Bouton and Stzwarentruber, 1991; Milad and Quirk, 2002; Bouton, 2002; Myers and Davis, 2007), as shown in Figure (A compares the behavior characteristics after retreat and forgetfulness, b, C, and D, respectively, represent the behavioral characteristics of spontaneous recovery, renewal, and reconstruction after subsidence).

Reconsolidation model of conditional fear memory fade

In recent years, scholars have proposed a memory reconsolidation model, arguing that solid memory can not be achieved after a single consolidation, but need to be consolidated many times to form. Even if the memory that has been stored intact for a long time, it will be temporarily returned to an unstable state after being re-extracted and activated, and a new consolidation phase will be required to be maintained, during which a new protein synthesis is required to return to a stable state, and the process is easily disturbed, which may be rewritten (rewrite) or cleared (or cleared) erase) original memory (Nader, Schafe, sledoux, 2000a; Eisenberg, Kobilo, Berman, and Dudai, 2003; Lee, Everitt, and Thomas, 2004).

There are currently two main types of memory reconsolidation activation models: one is to present a separate extraction test (an isolated remote lying trial); The other is that CS-US is rendered at the same time. Misanin, io

2019101169 11 Oct2019

Miller, and Lewis (1968) were the first to observe memory reconsolidation, and he presented condition stimulation in a separate electroshock therapy experiment after 24 h of acquired conditional fear in mice, leading to the loss of memory of the original fear. The difference between reconsolidation and consolidation is that they occur at different stages, with consolidation occurring during the formation of new memories, and reconsolidation safters occurring after the extraction of consolidated memories (Nader and Hardt, 2009). The reconsolidation lasts about 6 h, called the reconsolidation time window, in which memory has plasticity characteristics and is important for the consolidation of the original memory.

Monfils et al. (2009) applied traditional retreat training to the reconsolidation time window, proposing the practice intervention paradigm for extracting retreat, based on the principle that traditional retreating training can change the fear price of CS and place it in the reconsolidation time window (by presenting a separate extraction test scan (an isolated test) trial), which puts memory in an unstable state), thus forming a new CS non-fear effect, rewriting the initial fear memory, weakening memory traces and channels, and blocking the fear response. Reconsolidation is an adaptive update mechanism. By re-consolidating, new information can be incorporated into the original memory, so entering new information in the re-consolidation window may

2019101169 11 Oct2019 permanently rewrite fear memory (Schiller et al., 2010). Based on animal experiments, Schiller et al. (2010) applied the behavioral model of cancellation to human subjects. In the experiment, they used 3 groups of subjects, one control group, and two reconsolidation time windows (10 min). ; 6 h) of the experimental group, Two conditional stimuli (CS+, CS-). During the acquisition phase, CS+ matched a slight shock and CSdid not follow any stimulus. After 24 hours, the patients were regressed and lifted, and 24 hours after the regression, the re-recession training was performed. The whole process was treated with the skin electrical response as a fear reaction index. Results The spontaneous recovery of fear in the experimental group was much lower than that in the other two groups. The fear reconstruction was tested 1 year later. The 10 min experimental group showed no fear reconstruction effect, but the 6 h time window showed strong contrast with the control group. The fear reconstruction effect.

In real life, there may be more than one clue to cause a fear reaction, but multiple, each of which may potentially cause recalls and trigger fear responses. Therefore, it is important for the clinical application to verify whether the withdrawal is clue specific. The researchers believe that the efficacy of the paradigm of the withdrawal behavior is similar to that of drug interference in the reconsolidation time window, which is a

2019101169 11 Oct2019 neurological characterization that changes the fear memory by a significant time-dependent molecular mechanism induced by CS-no US. The above experiments showed that the fear memory was trained to fade in the re-consolidation time window, preventing the spontaneous recovery and reconstruction of fear, and that the effect was longer,' and that this treatment selectively affected the extraction condition stimulation without affecting the fear memory of non-extraction condition stimulation. At the same time, it can be concluded from the experiment that the selection and clue of the point in time within the time window of re-consolidation play an important role in extracting the fading paradigm.

The measurement principle of the motion threshold (MT)

Before initiation of any TMS treatment, the correct stimulation intensity for the procedure needs to be established, and the stimulation intensity of the TMS therapeutic procedure is based on every patient's sensitivity, which is also known as the patient's motor threshold (MT) or RMT (resting motor threshold).

With the TMS therapy system, the first criterion of MT is measured by the observance of a visible muscle twitch of the whole palm or figures. Especially, Thumb, index figure or middle finger shows significant twitch after stimulation of the primary motor cortex (Brodmann area 4), known as Ml, the primary region of the motor system and majorly works in association with other motor areas on brains of humans that is located in

2019101169 11 Oct2019 the dorsal portion of the frontal lobe. In terms of the second criterion, it is the correct region of the primary region of the motor system if the intrinsic hand muscles in the motor area on the opposite hemisphere in half of the whole stimulations. For example, the right hand of a patient should be observed if the five out of ten stimulations affect his or her left hemisphere. Then, the lowest possible stimulation intensity with a significant visible twitch of the hand represents the patient's motor threshold value.

Moreover, there is the other method that is able to measure MT by observing the peak and trough of the wave displaying on the screen of TMS equipment. For the accuracy of the measurement, the measurement electrodes are required to be worn on the two parts of the patient's hand the thumb abductor muscle and the wrist joint. The measuring electrode worn on the thumb abductor muscle is the positive electrode, and the measuring electrode worn at the bony prominence of the wrist joint is the negative electrode. At the interface of the MT measurement, TMS's program can automatically calculate the difference between the peak and the trough of the wave generating by the patient, and get the MT.

The practical operation of defining MT

In order to begin a motor threshold determination procedure, turn on the motor evoked potential (MEP) model on the TMS machine and attach the figure-of-eight coil on the patient's head is necessary. Besides, for the

2019101169 11 Oct2019 motor threshold determination procedure, one will need a treatment cap as an assistant position system to locate the approximate area where Ml is situated. For patients who are anxious about the procedure, applying a few stimulations to the back of the arm is helpful to get the patient familiar with the stimulation.

Before the next step of measuring MT, the operator needs to be sure that the treatment cap fits the patient's head snugly and correctly. There are two different methods of fitting the treatment cap in the correct position: the 10-20 international placement system or a built-in TMS navigation system.

1. The 10-20 international placement system

The 10-20 international placement system is the most widely used method to describe the placement of electrodes at specific intervals along with the head, and initially, it consisted of 21 electrodes, which is most prevalent at EEG study. In other researches, this method is used to specify the cerebral cortex and make a precise orientation.

To find the area of the scalp above the motor cortex, first, identify the location of nasion and inion. The nasion is the intersection of the frontal bone and to nasal bones on the skull, which can be determined as the most profound depression on the midline between the nose and forehead. The inion is the most prominent projection of the occipital bone at the lower rear part of the skull. Measure the distance between the nasion and

2019101169 11 Oct2019 inion along the midline of the head. It is about the halfway point between these two landmarks where the Cz mark is located.

Second, the operator has to measure the distance between two tragi of each ear and determine the line passed through the approximated halfway point between the nasion and the inion. The intersection point, also known as the vertex, of two measured distance, is the Cz mark, which should be found at around the center of the head skull, the halfway point between the two tragi and between the nasion and the inion.

According to the opposite principle mentioned in the above paragraphs, the motor cortex for the right hand is located at the left and front side of the vertex. On the contrary, the motor cortex for the left hand is located to the right and front side of the vertex. It is one point on the offside of the patient's head five centimeters lateral to the vertex along the distance between the two tragi of ears and the other point along with the midline five centimeter anterior to the vertex. Between the two points, there is a line that the rough MT area for the contralateral hand is located. After that, the coil should be applied to the patient's head as a treatment means. The optimal coil orientation for finding the MT is achieved by keeping the coil at an angle of 45 degrees to the midline with the center of the coil in contact with the scalp. Such that the plane of the surface of the coil is tangential to the curvature of the head. This orientation is obtained by keeping the straight edge of the marking plate parallel to the cap midline.

2019101169 11 Oct2019

After that, the patient's head is placed by the center of the coil at the midpoint of the dotted line. Also, the process of searching for the MT is by delivering single stimulations while moving the coil in small increments along the line while continuously observing the hand for a twitch. The operator then starts the stimulation with an intensity of 40 to 50%. If no response, it should be a gradual increase in the intensity until a response is observed. A random interval between the single stimulations of between three to seven seconds is acted. Once the location of the most robust response is found, incrementally lower the intensity to find the lowest possible value where at which is still observed in half of the whole (five out of ten) stimulations. The stimulation intensity value is the individual patient's MT.

2. The Brainsight TMS navigation system

The Brainsight TMS navigation system is a comprehensive tool that enabling a TMS coil to be located over a specified target location based upon an individual’s image generating from fitting a big database of numerous skull patterns. The generating image on the TMS screen is a 3D curvilinear reconstruction of the brain. The system is Effectively assisting the operator to locate the specific location of the brain and save time that is wasted in the inaccurate search for the location.

The first step for computer-based navigation is to put a headband with Positioning balls on the head of the patient. Then, the Positioning pen

2019101169 11 Oct2019 captured by the navigation system is used to locate the nasion and two tragi before drawing the structure of the skull by the same pen. It is about 500 point of drawing the whole skull can make sure the system recognizes and fit the skull structure.

After the brain image displaying on-screen, the ideal location is marked, and the coil can fit a more precise position of MT. Observation of twitches is needed for the final decision of the MT. It is as complete the same as the following procedure of 10-20 international placement system since the deviation only occurs on the roughly orientated process between two methods.

It is necessary to ensure the whole navigation system, especially the Light-sensing camera, be able to capture the positioning balls on all equipment used and on the headband. The capture-checking function is inner the navigation system that displaying green light for ‘captured’ and red light for ‘capture-losing.’

Procedure

Participant participants. One participant understood the wrong experimental task, and one participant failed to acquire the fear, so the effective test was 4. Subjects were right-handed, with no physical illness and mental disorder, normal vision or corrected visual acuity, no color blindness, no hearing impairment, and had not participated in similar situational experiments

2019101169 11 Oct2019 before. Normal work and rest were maintained during the two days of the experiment to rule out the deviation of the experimental subjects. Before the start of the experiment, the participants were told that during the experiment, a slight electric shock will be applied to the arm. The use and strength of the electric shock instrument are scientifically assessed and will not cause any harm to the human body. If there are any symptoms in the experiment, you can terminate the experiment at any time. All information and data related to the subject will be kept strictly confidential. The subject must sign the informed consent form after understanding the situation.

Participants were randomly assigned to two groups, TMS treatment group and behavioral control group.

Research design

This study used experimental method. Mixed design. The inter-group variables were treated by two kinds of experimental treatments (TMS treatment group, behavioral control group), that is, two methods were used to intervene in fear memory; the intra-group variables were experimental time variables, that is, all subjects were subject to conditional fear acquisition. The dependent variable of the experiment is the level of fear response of the subject.

The behavioral control subjects were treated in the same laboratory using the same experimental procedure as compared to the TMS treatment

2019101169 11 Oct2019 group. In order to avoid the impact of the experimental materials on the subjects, all materials in the experiment will be balanced.

Research tools (1) Neutral stimulation experimental materials two assessed neutral mood picture materials were used as the conditional stimulates in this study. The brightness and size of the pictures are the same. The background of the picture is black and the location is in the center of the computer screen.

campus scene pictures and 4 irrelevant scene pictures were selected before the start of the experiment, and 10 healthy non-testees were asked to assess four dimensions' level(emotional arousal, average pleasure, emotional dominance and relevance to the group (reminiscent of school violence)) to minimize the likelihood that the image itself would affect the subject. All the images selected were unfamiliar to the participants before. Through the paired sample t test, the final selection of emotional arousal, average pleasure, and emotional dominance was not significantly different (p>0.05), and the correlation degree was significantly different (p<0.05) of a campus scene picture and 1 Unrelated scene pictures as experimental materials. The picture of the campus scene will be accompanied with unconditional stimulation (electrical shock), as CS+. And the other conditional stimulus will not be accompanied with any unconditional stimulation, as CS-. Unconditional stimulation used an

2019101169 11 Oct2019 electric stimulator to shock the right arm of the subject to cause a fear reaction. The electric shock intensity is assessed in advance according to the tolerance of each subject, and is controlled within the acceptable range of each subject and does not cause harm to the human body. The duration of each shock was 500ms.

(2) Measurement indicators

Physiological indicators: skin electrical response

Skin conductance response (SCR): is an epidermal potential that reflects the functional status of the sympathetic ganglia and can be induced by endogenous or exogenous stimuli. It is the main measure of conditional fear response measured in this study. The bioelectric 16-channel physiological recorder (model MP 150) was used during the experiment to record the skin conductance responses (SCR) signal (Lonsdorf et al., 2017). In the experiment, the finger of the test was first wiped with medical alcohol, and then the Ag/AgCl electrode was fixed to the end of the left index finger and the middle finger of the subject, and the other port of the electrode was connected to the EDA100C module of the physiological recorder. The sampling rate was 500 Hz. The analysis software uses the AcqKnowledge 4.2 software that comes with the Biopac 16-channel physiological recorder.

Program

2019101169 11 Oct2019

The experimental procedure is divided into three stages: preliminary preparation stage, experimental operation and data analysis.

Electric shock intensity assessment stage: Before the official start of the first day of the experiment, each participant was required to receive a shock intensity assessment to ensure that the strength made the subject feel uncomfortable but tolerable. The range of electric shock intensity is 10—50 V. The tester needs to give a 0-10 rating for the electric shock after receiving the electric shock (0 is comfortable, 8 is extremely uncomfortable but can endure, 9 is painful and can not stand it)). The shock intensity assessed as level 8 was selected as the shock intensity of the entire experimental procedure. The duration of each shock is 500ms, and the shock intensity of the test is no longer changed in each subsequent experimental session.

In the formal experiment, all materials were presented by Matlab 2013a, and the experiment lasted for 2 days. The schematic diagram of the study is shown in the figure.

The experimental materials were programmed on the same computer screen using Matlab software (to avoid interference, the subjects wore earplugs before starting). First, the white gaze point · is presented for 4000ms in the center of the screen, and then the conditional stimulus CS is randomly presented for 4000 ms. If CS+ appears with US, the US duration is 500 ms and then disappears together. The trial interval (ITI) is

2019101169 11 Oct2019

4000-8000ms, and the screen displays a white gaze point “·” during the interval, ensuring that the skin value of the subject can be reduced to the standard level (as shown).

The formal experiment is divided into 2 days. The first day is the habituation stage, the fear acquisition stage, the extinction stage and the TMS treatment stage. The second day is the memory recall stage. The whole experiment is performed by the left hand connected to the physiological recorder to collect the skin electricity, the right arm. Connect the electric stimulator.Before the start of the formal experiment, the experimenter first explained the instruction to the participant in detail, and ensured that the subject understood the meaning of the instruction and entered the acquisition and extinction stages of the first day. Before the formal experiment began, the subjects first practiced the graphics, opened the AcqKnowledge 4.2 software and Matlab 2013 version and run the program. The air of the physiological recorder electrode was calibrated. After the baseline level, the participant's left index finger was connected with the middle finger. Physiological recorder, the right arm is connected to the electrical stimulator. Enter the subject information and run the habituation phase. CS+ and CS- each presented 3 rounds, randomly presented alternately, with a presentation time of 4000 ms and a stimulation interval of 4000-8000 ms. Inform the participants to pay attention to them, no need to respond, and do not issue any guiding

2019101169 11 Oct2019 instructions to the subjects. The habituation stages of the two groups were identical.

In the fear acquisition phase, the basic operation is the same as above. After entering the subject information, run the Learning phase. CS+ and CS- each appear 20 times, randomly appearing alternately, with a presentation time of 4000 ms and a stimulation interval of 4000-8000 ms. There were 8 cases in CS+ with electric shock US, 12 times without electric shock US, and the electric shock ratio was 40%. CS- is not accompanied by an electric shock. At this stage, the participants were required to concentrate on the computer screen. Observe the electrical response of the test skin. After the acquisition phase, the participants rested for 10 minutes.

In the fear extinction phase, the basic operation is the same as above, and the Extinction phase is run after inputting the test information. CS+ and CS- each appear 20 times, randomly appearing alternately, with a presentation time of 4000 ms and a stimulation interval of 4000-8000 ms. In this stage, the conditional stimulation was not accompanied by electric shock, and the skin electrical reaction of the test was observed.

In the TMS treatment phase, the distance between the ears of the subject, the distance from the nasal root to the occipital bulge, and the length of the head circumference were measured. The distance between the distance from the midline (X) and the distance from Vertex (Y) was

2019101169 11 Oct2019 measured using the Beam F3 Shortcut software to determine the F4 brain area. Opened the TMS instrument, selected iTBS, entered the test information, adjusted the stimulation intensity and treated for 3 minutes. In this stage, the experimental group received a stimulus intensity of 70% of the measured exercise threshold, while the behavioral control group only received pseudo-stimulation.

In the Recall phase, the basic operation is the same as above. After inputting the test information, the Recall phase is run. CS+ and CS- are presented 20 times, randomly alternately presented, the presentation time is 4000ms, and the stimulation interval is 4000-8000ms. At this stage, the conditional stimulation was not accompanied by electric shock, and the skin electrical response of the test was observed.

Results

The SCR values of the participants in each stage are as shown in the figures.

The first day of fear acquisition:

For the data in the acquisition phase, The t-test of SCR values between CS+ and CS- was significant (p<0.05).This indicate that all the subjects successfully acquired fear. The t-test of SCR values between the experimental group and the control group was not significant (p>0.05). There is no significant difference in the conditional fear learned between the two groups.

2019101169 11 Oct2019

The first day of the extinction phase:

For the data of the extinction stage, the SCR average value of the two groups of subjects in the acquisition stage was used as the skin electrical index of fear acquisition, and the SCR average value of the extinction stage was used as the skin electrical index of fear extinction, and the two values were subjected to t test. The SCR values of the acquisition stage in the experimental group and the control group were significantly different from the SCR values of the extinction stage (p<0.05), and the extincted SCR values were smaller than the acquired SCR values, which indicating that the fear extinction of the two groups was successful.

The second day of the Recall phase:

The index of fear recurrence was the average of the SCRs of all trials when the experiment was performed on the next day, and compared with the regressed SCR values. The t-test results showed that there was no significant difference in SCR between Recall stage and extinction stage in two groups (p>0.05), which indicating that there was no recurrence of fear after extinction; In the Recall stage, there was no significant difference in SCR values between the experimental group and the control group(p>0.05), which indicating that there was no significant difference in the extent of extinction between the two groups.

Discuss

2019101169 11 Oct2019

In this study, multisensory combination stimulation (electric stimulation + picture) was used as a conditional stimulus to examine the effect of retrieval-extinction a single clue (picture) on the extinctionof conditional fear memory.

The study found that both the experimental and control groups successfully completed the acquisition and extinction of fear. In the Recall test on the second day, there was no recurrence of fear in both groups, but there was no significant difference in the SCR values between the two groups, which indicating that there was no significant difference in the degree of fear extinction between the two groups. Possible explanations for this result are as follows. First, although both groups of participants succeeded in fear acquisition, the p-value could not indicate the magnitude of the effect, which means that the specific amount of fear in the two groups could not be compared. And the fear of the two groups was successfully extincteded, but it was not possible to specifically compare the degree of fear of the subject's . It should be considered to further analyze the effect amount. Second, because the acquisition method and the extinction method are relatively simple, the subject may have fatigue effect during the experiment, which affects the skin electrical value. Third, when the subjects were treated with TMS, the location of the F4 brain region may not be accurate, or the subjects in the

2019101169 11 Oct2019 control group were more sensitive, even if they received pseudo-stimulation, it may have a certain effect.

Based on the previous studies, this study used human-subjects to apply the retrieval-extinction paradigm to more complex conditional fear memories, and proved that the retrieval-extinction paradigm using a single stimulus can be attenuated to some extent by the composite. The fear response caused by the stimulus eliminates the conditional fear caused by the compound stimulus cues. However, this study does not clarify how the stimulation is coded in the process of connection learning. The two stimulation cues of electrical stimulation and picture are stored as a mixed stimulus, or as two stimuli which have a connection with the US but exist difference. When the retrieval is activated, a single cues activates one component or both components are activated. The further research is needed in these aspects.

Research significance

Due to ethical issues, in the case of unstable interventions that eliminate the paradigm, we are not directly able to take individuals with traumatic experiences as subjects. Therefore, in the study we used the conditional fear paradigm to simulate trauma to achieve the transition from basic research to clinical research.

2019101169 11 Oct2019

In addition, the use of high-frequency rTMS as a treatment in this study. Repeated transcranial magnetic stimulation (rTMS) as a new physical therapy technology, has received extensive attention in psychiatry in recent years, and it has good clinical effectiveness and safety . FDA has approved it for the treatment of depression. Previous studies have explored the clinical efficacy of high-frequency rTMS combined with paroxetine in military PTSD, providing new measures for the treatment of military PTSD. This study explores the therapeutic efficacy and safety of TMS in the treatment of fear responses caused by other traumatic events. Research limitations

Limitations of experimental materials. In the experiment, electrical stimulation was used as an aversive stimulus, and the fear of electrical stimulation was easy to get used to. The subjects were accustomed to the intensity of electrical stimulation after a period of experimentation. Therefore, the resulting conditional fear reaction may not be obvious. It may also cause the subject to reduce the discrimination of neutral conditional stimuli.

The method of subsidence needs to be changed. Better methods of regression of traumatic memory should be explored, such as the use of imaginary exposure instead of repeated presentation of image stimuli. Because the subject has a fatigue effect on the repeated rendering of the picture, it may lead to a decrease in the SCR value. Therefore, in this test,

2019101169 11 Oct2019 it is necessary to further test whether the result of the extinction is caused by the experimental operation or the fatigue effect of the subject.

The accuracy of the positioning of the brain area. Due to the uniqueness of the subjects, we were unable to completely ensure the accurate positioning of the brain regions of each subject. Therefore, the accuracy of the determination of the threshold of the subjects needs to be further verified. Therefore, we should explore more precise positioning methods. Outlook

The retrieval-extinction paradigm is a major breakthrough in basic research in recent years. It is a new intervention paradigm aimed at “erasing” fear memory based on the theory of memory re-consolidation. At present, foreign scholars have more research on the cancellation of the paradigm of CS, but the research results are controversial. Some studies have found that the CS retrieval-extinction paradigm can rewrite the conditional fear memory and prevent the recurrence of fear (Schilleretal., 2010). And otherstudies found that the paradigm failed to prevent the recurrence of fear (Costanzi et al., 2011; Kindt & Soeter, 2013). It can be seen that the intervention effect of CS retrieval-extinction paradigm is not stable. Therefore, it is especially important to re-examine the intervention effect of CS retrieval-extinction and explore the boundary conditions of its effects. Compared with the traditional extinction paradigm, CS retrieval-extinction can eliminate the fear and reduce the recurrence rate

2019101169 11 Oct2019 of fear memory and traumatic memory. It is a new paradigm of trauma intervention that needs attention in the future, and its effect needs to be further tested in clinical practice. Cause compared with laboratory experiments, clinical problems are more complicated. For example, the CS that induces PTSD is more complicated, the US intensity is greater, the fear formation time is longer, and the individual response is stronger. Complex reality factors increase the difficulty of clinical research, and the introduction of the retrieval-extinction paradigm into clinical practice is an urgent research direction.

And the technique of transcranial magnetic stimulation also provides us with a relatively non-invasive treatment. Although the therapeutic effect was not effectively explored in this experiment, according to previous research results and literature review, repeated transcranial magnetic stimulation may enhance synaptic plasticity, or improve neuroelectrophysiology and cerebral cortex excitability by promoting synaptic remodeling. Or to regulate the level of neurotransmitters to improve cognitive function, so in the future you can consider the use of transcranial magnetic stimulation or the use of transcranial magnetic stimulation combined with other treatments (drugs, counseling, etc.) to treat PTSD.

Claims (2)

1. Method of TMS for extinction about early traumatic memory, wherein said theoretical model of conditional fear is based on Pavlov condition reflection and is one of the most important animal models to explore the processes of fear acquisition, storage, extraction, and retreat, as well as the cognitive neural mechanisms in these processes.

2. According to claim 1, wherein two main types of memory reconsolidation activation models: one is to present a separate extraction test; the other is that CS-US is rendered at the same time.