Novelty-retrieval-extinction paradigm to decrease high-intensity fear memory recurrence.

BACKGROUND: The retrieval-extinction paradigm based on memory reconsolidation can prevent fear memory recurrence more effectively than the extinction paradigm. High-intensity fear memories tend to resist reconsolidation. Novelty-retrieval-extinction can promote the reconsolidation of fear memory lacking neuroplasticity in rodents; however, whether it could effectively promote high-intensity fear memory reconsolidation in humans remains unclear. METHODS: Using 120 human participants, we implemented the use of the environment (novel vs. familiar) with the help of virtual reality technology. Novelty environment exploration was combined with retrieval-extinction in fear memory of two intensity levels (normal vs. high) to examine whether novelty facilitates the reconsolidation of high-intensity fear memory and prevents recurrence. Skin conductance responses were used to clarify novelty-retrieval-extinction effects at the behavioral level across three experiments. RESULTS: Retrieval-extinction could prevent the reinstatement of normal-intensity fear memory; however, for high-intensity fear memory, only the novelty-retrieval-extinction could prevent recurrence; we further validated that novelty-retrieval-extinction may be effective only when the environment is novel. LIMITATIONS: Although the high-intensity fear memory is higher than normal-intensity in this study, it may be insufficient relative to fear experienced in real-world contexts or by individuals with mental disorders. CONCLUSIONS: To some extent, these findings indicate that the novelty-retrieval-extinction paradigm could prevent the recurrence of high-intensity fear memory, and we infer that novelty of environment may play an important role in novelty-retrieval-extinction paradigm. The results of this study have positive implications for the existing retrieval extinction paradigm and the clinical treatment of phobia.

Contingency Reversal in Conditioned Fear Learning: The Moderated Mediation Model of Intolerance of Uncertainty and Instruction.

Objective: The study aimed to examine the roles of anxiety and intolerance of uncertainty (IU) in conditioned fear learning under an uncertain context induced by the contingency reversal of the association between the conditioned stimulus and the unconditioned stimulus (CS-US). Methods: The study sample comprised 53 participants, randomly divided into two groups: a non-instruction group and an instruction group. The experimental procedure encompassed five stages: pre-acquisition, acquisition, generalization, reversal acquisition, and reversal generalization. Our study primarily focused on analyzing a moderated mediation model. Results: In the instructed group, we observed that the reversed fear generalization response was directly influenced by the pre-reversal fear generalization response, while also being indirectly mediated by the IU factor. However, in the non-instructed group, we did not find a significant mediating effect of IU. Moreover, we noted that the mediation of IU was contingent on the instructional information. It is noteworthy that anxiety did not exhibit a discernible role in conditioned fear within the uncertainty condition in our study. Conclusion: The findings provide novel insights into fear-related phenomena, emphasizing the intricate interplay between individual traits and fear generalization under conditions of uncertainty. They contribute to understanding the mechanisms of emotional and cognitive interactions in uncertain conditions.

The influence of word concreteness on acquired positive emotion association: An event-related potential study.

The ability to acquire positive emotions from words is essential to psychological well-being. How word concreteness affects the process of positive emotion acquisition remains unknown. Here, using an evaluation conditioning paradigm, participants learned the association between pseudowords and concrete/abstract and positive/neutral words. Behavior and event-related potential data were recorded while participants performed emotional recognition tasks. Behavioral results showed that, for neutral words, concrete words were more accurate than abstract words, whereas for positive words, abstract words were more accurate than concrete words. Moreover, N1 and P2 amplitudes in the pseudowords were modulated by interacting word emotion and concreteness. Specifically, pseudowords associated with neutral concrete words elicited larger N1 and P2 amplitudes than pseudowords associated with neutral abstract words. Conversely, N1 and P2 amplitudes in pseudowords associated with positive abstract words were not significant compared to those in positive concrete words. Additionally, an emotional effect was observed when pseudowords were associated with abstract words, showing higher P3 amplitude for the pseudowords associated with positive abstract words than neutral abstract words. No significant effects were found for the pseudowords associated with positive abstract or concrete words. These findings suggest that association learning may influence the early attention processing of emotion acquisition from words, and emotional information of positive abstract words might boost positive emotion acquisition, thereby eliminating the acquisition advantage from positive concrete words.

Role of Cue Training, Context, and Stimulus Intensity on Fear Generalization in Humans.

Fear generalization is a crucial mechanism underlying maladaptive behavior, but factors influencing this process are not fully understood. We investigated the effects of cue training and context on fear generalization and how cognitive rules influence responses to different conditions. We also examined the role of stimulus intensity in fear generalization to provide insight into fear generalization mechanisms. Participants (n = 104) completed a fear emotion task with two stages: acquisition and generalization testing. Subjective fear expectancy ratings were used as outcome measures. Participants who received single threat cue training exhibited stronger fear generalization responses than those who received discrimination training with threat and safe cues. Participants who received discrimination training and used linear rules had the strongest fear response to the largest stimulus. Therefore, a safe cue may mitigate fear generalization but could increase fear responses to more intense stimuli. Altering context did not change the fear generalization response because fear generalization is mainly governed by the association between the conditioned stimulus and the unconditioned fear stimulus. The present study emphasizes the multifaceted nature of fear generalization and the importance of examining multiple factors to understand this phenomenon. These findings elucidate fear learning and provide insights needed for effective interventions for maladaptive behavior.

Game-matching background music has an add-on effect for reducing emotionality of traumatic memories during reconsolidation intervention.

Introduction: Hospital is a stressful place of employment, and a high proportion of healthcare workers, especially the ICU (Intensive Care Unit) nurses were found to be at risk of PTSD. Previous studies showed that taxing working memory through visuospatial tasks during the reconsolidation process of aversive memories can reduce the number of intrusions afterwards. However, the finds could not be replicated by some researches, indicating there may be some boundary conditions that are subtle and complex. Methods: We performed a randomized controlled trial (ChiCTR2200055921; URL: www.chictr.org.cn). In our study, a series of ICU nurses or probationers who performed a cardiopulmonary resuscitation (CPR) were enrolled and instructed to play a visuospatial music tapping game ("Ceaseless Music Note", CMN; Beijing Muyuan Technology Co., Ltd., Beijing, China) at the fourth day after CPR. The numbers of intrusions each day were recorded from the first to the seventh days (24 h×6 day), and the vividness and emotionality of CPR memories were rated at the 4th and 7th days. These parameters were compared between different groups (game with background sound; game with sound off; sound only; none). Results: The game-matching background music can have an add-on effect for single tapping game with no sound in reducing the emotionality of previous aversive memories. Discussion: We proposed that flow experience (the subjective experience of effortless attention, reduced self-awareness, and enjoyment, and may be induced by optimal skill-demands compatibility in challenging tasks) as a key boundary condition for successful reconsolidation intervention. Clinical trial registration: www.chictr.org.cn, identifier: ChiCTR2200055921.

Effects of the retrieval-extinction paradigm with abstract reminders on fear memory extinction.

Reactivated fear memories may enter an unstable state that could be interrupted by behavioral interventions such as the retrieval-extinction procedure. Studies of pharmacological interventions have shown that retrieval cues are not necessarily an exact reduplication of initial conditioned stimuli (CSs); they can instead be abstract word cues. However, the effectiveness of using abstract reminder cues in behavioral intervention procedures remains unknown, as do the conditions under which they are effective. The typicality of CS and the abstraction level of reminders are also likely to be important in the paradigm but have not been investigated to date. Here, in three experiments (n = 107), we manipulate the fear conditioning process, including single CS-unconditioned stimulus (US) and multiple CS-US connections, as well as the CS typicality and abstraction level of reminder cues, to explore the conditions for adopting retrieval-extinction with abstract reminders. The results of Experiments 1 and 2 show that the abstract cue is ineffective for use as a reminder in the procedure; this is the case for single exemplar category learning and perceptual discriminative learning, independent of the typicality of CS+ or the abstraction level of reminder cues. Only the outcome of Experiment 3, which contains multiple CS-US connections, shows no indication of fear return. The limitations of the study and possible interpretations of the results are discussed.

Psychometric properties of the post-traumatic stress disorder checklist for DSM-5 (PCL-5) in Chinese stroke patients.

BACKGROUND: Stroke is a devastating disease and can be sufficiently traumatic to induce post-traumatic stress disorder (PTSD). Post-stroke PTSD is attracting increasing attention, but there was no study assessing the psychometric properties of the PCL-5 in stroke populations. Our study was conducted to examine the psychometric properties of the PTSD Checklist for DSM-5 (PCL-5) in Chinese stroke patients. METHODS: This was a cross-sectional observational study conducted at our hospital. Three hundred and forty-eight Chinese stroke patients came to our hospital for outpatient service were recruited. They were instructed to complete the PCL-5 scales and were interviewed for PTSD diagnosis with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5). The cutoff scores, reliability and validity of the PCL-5 were analyzed. RESULTS: PCL-5 scores in our sample were positively skewed, suggesting low levels of PTSD symptoms. The reliability of PCL-5 was good. Exploratory and confirmatory factor analyses indicated acceptable construct validity, and confirmed the multi-dimensionality of the PCL-5. By CFA analysis, the seven-factor hybrid model demonstrated the best model fit. The PCL-5 also showed good convergent validity and discriminant validity. Receiver operating characteristic (ROC) analyses revealed a PCL-5 score of 37 achieved optimal sensitivity and specificity for detecting PTSD. CONCLUSIONS: Our findings supported the use of PCL-5 as a psychometrically adequate measure of post-stroke PTSD in the Chinese patients.

Effectiveness of repetitive transcranial magnetic stimulation combined with a brief exposure procedure for post-stroke posttraumatic stress disorder.

The incidence of posttraumatic stress disorder (PTSD) following stroke ranges from 6.5 % to 25 %. Presently few studies have focused on its treatment. Repetitive transcranial magnetic stimulation (rTMS) is often applied as a rehabilitation method after stroke, and it also represents a novel approach to PTSD. The aim of this study was to explore the effect of rTMS (or combined with a brief stroke re-exposure) on treating post-stroke PTSD. Sixty participants with post-stroke PTSD were randomly assigned into three groups (rTMS + brief exposure group, TMS + BE; rTMS alone group, TMS; sham treatment group, ST) and received 10 sessions of treatment accordingly over two weeks. Changes in PTSD symptoms (Impact of Event Scale-Revised, IES-R) were evaluated at pre-treatment (T1), the end of the first (T2), and the end of the second treatment week (T3). At the three-month follow-up (T4), a PTSD interview and IES-R assessment were given. Results showed that from T1 to T3, IES-R (and its intrusion subscale) scores of TMS + BE group and TMS group were significantly lower than the ST group, and the effect remained at three-month follow-up. The treatment effect was comparable between TMS + BE group and TMS group at T3, however, it was better for TMS + BE group than TMS group at T2, indicating a brief exposure promotes the effect of rTMS. At follow-up, the rates of PTSD were lower in TMS + BE group and TMS group than ST group. In conclusion, rTMS can effectively treat post-stroke PTSD and the effects may be accelerated by combining a brief exposure procedure. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100043444.

Succinic Ester-Based Shape Memory Gelatin Sponge for Noncompressible Hemorrhage without Hindering Tissue Regeneration.

Shape memory sponges are very promising in stopping the bleeding from noncompressible and narrow entrance wounds. However, few shape memory sponges have fast degradable properties in order to not hinder tissue healing. In this work, based on cryopolymerization, a succinic ester-based sponge (Ssponge) is fabricated using gelatin and bi-polyethylene glycol-succinimidyl succinate (Bi-PEG-SS). Compared with the commercially available gelatin sponge (Csponge), Ssponge possesses better water/blood absorption ability and higher mechanical pressure over the surrounding tissues. Moreover, in the models of massive liver hemorrhage after transection and noncompressive liver wounds by penetration, Ssponge exhibits a better hemostasis performance than Csponge. Furthermore, in a liver regeneration model, Ssponge-treated livers shows higher regeneration speed compared with Csponge, including a lower injury score, more cavity-like tissues, less fibrosis and enhanced tissue regeneration. Overall, it is shown that Ssponge, with a fast degradation behavior, is not only highly efficient in stopping bleeding but also not detrimental for tissue healing, possessing promising clinical translational potential.

Neuroticism and fear of COVID-19 during the COVID-19 pandemic: Testing the mediating role of intolerance of uncertainty and sense of control among Chinese high school students.

Since the COVID-19 pandemic broke out in 2019, neuroticism has been proven a predictor of fear of COVID-19 infection. However, only few studies have been conducted on the factors affecting the relationship between neuroticism and this kind of fear. The present study is aimed at analyzing the role intolerance of uncertainty (IU) and sense of control (SOC) play in relation to neuroticism and the fear of COVID-19. We conducted a cross-sectional study in Guangdong and Guangxi provinces, China, and we collected complete datasets from 792 high school students. The main results can be described as follows: (a) individuals with high neuroticism tended to have higher intolerance of uncertainty (IU) and a lower sense of control (SOC); (b) IU and SOC played a mediating role between neuroticism and fear of COVID-19, and a serial mediation effect was found between these factors; (c) after controlling for both IU and SOC, the effect of neuroticism on fear was no longer significant. The results suggested a critical role of IU and sense of control in the causal relationship between neuroticism and fear.

Stimulus diversity increases category-based fear generalization and the effect of intolerance of uncertainty.

Fear generalization refers to conditioned fear responses extending to related stimuli and fear overgeneralization is a key feature of pathological anxiety. Along with perception similarity, conceptual relations affect fear generalization. We investigated whether stimulus diversity-an important principle of category-based induction-influences fear generalization. Induction studies have shown that generalization from a premise involving diverse instances is stronger than that from non-diverse instances. We adopted this framework for fear learning and established two groups. The diverse group developed fear in response to diverse instances from one category, while the non-diverse group acquired fear of non-diverse instances from the same category. An effect of stimulus diversity was observed in shock-expectancy ratings, with the diverse group displaying higher fear generalization than the non-diverse group. We also tested whether intolerance of uncertainty (IU) might affect the difference in fear generalization between the two conditions. Individuals with higher IU showed reduced difference in fear generalization between two conditions, mainly driven by heightened fear generalization to novel stimulus with ambiguous threat levels in the non-diverse condition. This study helps illustrate the mechanisms behind differential category-based fear generalization and provides a potential explanation for why higher IU individuals may develop anxiety disorders following trauma.

Early Safety Discrimination Under Uncertainty in Trait Anxiety: An Event-Related Potential Study.

Detection of safety-threat signals during uncertainty is an important mechanism of developmental anxiety disorder (AD). Although extensive research has focused on the detection of uncertain threat signals in anxious individuals, relatively little attention has been given to the identification of safety signals during uncertainty, which is an important way to relieve anxiety in individuals with AD. To investigate this phenomenon, 16 subjects with high trait anxiety (HTA) and 16 with low trait anxiety (LTA) completed a modified cue-target task in certain and uncertain stimulus blocks. In the uncertain block, the cue was followed by a threat picture or safety picture in 20% of trials, respectively; in the certain block, the cue could be followed by a threat picture or a safety picture on 100% of trials. Behavioral responses and event-related potentials (ERPs) were recorded. The ERP results demonstrated that LTA participants exhibited larger P2 amplitudes in the detection of safety cues than of threat cues during the uncertain block, whereas HTA participants showed significant P2 amplitudes between the safety and threat cues during the certain block, impairing the detection of safety stimuli during uncertainty. However, all participants exhibited greater N2 amplitudes following threat cues in certainty or uncertainty conditions. These findings pertaining to the P2 amplitude suggested distinctive attentional biases between HTA and LTA individuals, whereas the N2 amplitude showed association learning in uncertain conditions, compensating for safety-threat detection in HTA individuals.

The Effect of Parental Phubbing on Depression in Chinese Junior High School Students: The Mediating Roles of Basic Psychological Needs Satisfaction and Self-Esteem.

Objective: To reveal the relationship between parental phubbing, basic psychological needs satisfaction, self-esteem, and depression and to explore the impact of parental phubbing on depression. Methods: A total of 819 junior high school students responded to the parental phubbing scale, basic psychological needs satisfaction scale, self-esteem scale, and depression scale in combination. Results: (1) Parental phubbing was significantly correlated with satisfaction of basic psychological needs, self-esteem, and depression. (2) Parental phubbing can not only be used to directly predict depression in junior middle school students but also has an indirect impact on depression through three pathways: a separate mediating effect on basic psychological needs satisfaction, a separate mediating effect on self-esteem and a chain mediating effect on both. Conclusion: Parental phubbing is a risk factor for depression, which can negatively affect the mental health of junior high school students.

The influence of social pain experience on empathic neural responses: the moderating role of gender.

Empathy for pain, the ability to share and understand the pain of others, plays an important role in the survival and development of individuals. Previous studies have found that social pain experience affects empathy for pain, but potential gender differences have not been considered. The stage of information processing during which gender is most likely to play a moderating role has yet to be clarified. In the current study, we set up two groups (social pain experience priming: social exclusion group; positive social interaction experience priming: social inclusion group) with a Cyberball game paradigm. We recorded the electrophysiological responses when participants were completing an empathy task. An early frontal P2 and N2 differentiation between painful stimuli and neutral stimuli was observed and females showed larger P2 amplitudes than males. At the P3 stage, in the social exclusion group, males showed similar parietal P3 amplitudes for painful and neutral stimuli, while females showed smaller P3 amplitudes for painful stimuli. At the central-parietal late positive potential (LPP) stage, females in the social inclusion group showed larger LPP amplitudes for painful stimuli than males. Our results suggest that gender plays a significant moderating role in how social pain experience affects empathy for pain during the late cognitive processing stage. Experiment 2 was designed to investigate the cognitive mechanism behind the results for the P3 component in females and the results partially confirmed our speculation. This study provides a neurophysiological basis for the dynamic gender differences in the effects of social pain experience on empathy for pain.

Is Acquired Disgust More Difficult to Extinguish Than Acquired Fear? an Event-Related Potential Study.

This study used the classical conditioned acquisition and extinction paradigm to compare which of the two emotions, acquired disgust and acquired fear, was more difficult to extinguish, based on behavioral assessments and the event-related potential (ERP) technique. Behavioral assessments revealed that, following successful conditioned extinction, acquired disgust was more difficult to extinguish. The ERP results showed that, at the early stage of P1, the amplitude of conditioned fear was significantly smaller than that of conditioned disgust, and both were significantly different from the amplitude under neutral conditions; at the middle stage of N2, the difference between the amplitudes of conditioned disgust and conditioned fear disappeared, but they were still significantly different from the amplitudes of conditioned neutral stimuli; at the late stage of P3, the difference between conditioned disgust and conditioned neutral stimuli disappeared, but the difference between conditioned fear and neutral stimuli remained, suggesting that acquired fear was more difficult to extinguish than acquired disgust in terms of how the brain works.

Establishing a Counter-Empathy Processing Model: Evidence from Functional Magnetic Resonance Imaging.

Counter-empathy significantly affects people's social lives. Previous evidence indicates that the degree of counter-empathy can be either strong or weak. Strong counter-empathy easily occurs when empathizers are prejudiced against the targets of empathy (e.g., prejudice against outgroup members) and activates brain regions that are opposite to those activated by empathy. Weak counter-empathy may have different neural processing paths from strong one, but its underlying neural mechanisms remain unclear. In this work, we used an unfair distribution paradigm, which can reduce participants' prejudice against persons empathized with, and functional magnetic resonance imaging (fMRI) to explore the neural mechanisms underlying counter-empathy. Here, empathy and counter-empathy shared a common neural mechanism, induced by unfair distribution, in the right middle temporal gyrus. Counter-empathy activated distinct brain regions that differed from those of empathic responses in different situations. The functions of these brain regions, which included the middle frontal, middle temporal and left medial superior gyri, were similar and mostly related to emotional regulation and cognitive processing. Here, we propose a process model of counter-empathy, involving two processing paths according to whether or not prejudice exists. This study has theoretical significance and broadens our understanding of the cognitive neural mechanisms underlying empathy and counter-empathy.

Different Influences of Negative and Neutral Emotional Interference on Working Memory in Trait Anxiety.

To examine the interaction of working memory (WM) type with emotional interference in trait anxiety, event-related potentials were measured in a combined WM and emotional task. Participants completed a delayed matching-to-sample task of WM, and emotional pictures were presented during the maintenance interval. The results indicated that negative affect interfered with spatial WM; task-related changes in amplitude were observed in the late positive potential (LPP) and slow waves in both the high and low anxiety groups. We also found an interaction among WM type, emotion, and trait anxiety such that participants with high levels of trait anxiety showed an opposite neural response to verbal and spatial WM tasks compared with individuals with low trait anxiety during the sustained brain activity involved in processing negative or neutral pictures in the delay phase. Our results increase our understanding of the influence of emotions on recognition and the vulnerability of those with trait anxiety to emotional stimuli.

3D-printed cell-free PCL-MECM scaffold with biomimetic micro-structure and micro-environment to enhance in situ meniscus regeneration.

Despite intensive effort was made to regenerate injured meniscus by cell-free strategies through recruiting endogenous stem/progenitor cells, meniscus regeneration remains a great challenge in clinic. In this study, we found decellularized meniscal extracellular matrix (MECM) preserved native meniscal collagen and glycosaminoglycans which could be a good endogenous regeneration guider for stem cells. Moreover, MECM significantly promoted meniscal fibrochondrocytes viability and proliferation, increased the expression of type II collagen and proteoglycans in vitro. Meanwhile, we designed 3D-printed polycaprolactone (PCL) scaffolds which mimic the circumferential and radial collagen orientation in native meniscus. Taken these two advantages together, a micro-structure and micro-environment dually biomimetic cell-free scaffold was manipulated. This cell-free PCL-MECM scaffold displayed superior biocompatibility and yielded favorable biomechanical capacities closely to native meniscus. Strikingly, neo-menisci were regenerated within PCL-MECM scaffolds which were transplanted into knee joints underwent medial meniscectomy in rabbits and sheep models. Histological staining confirmed neo-menisci showed meniscus-like heterogeneous staining. Mankin scores showed PCL-MECM scaffold could protect articular cartilage well, and knee X-ray examination revealed same results. Knee magnetic resonance imaging (MRI) scanning also showed some neo-menisci in PCL-MECM scaffold group. In conclusion, PCL-MECM scaffold appears to optimize meniscus regeneration. This could represent a promising approach worthy of further investigation in preclinical applications.

Social Exclusion Down-Regulates Pain Empathy at the Late Stage of Empathic Responses: Electrophysiological Evidence.

Social exclusion has a significant impact on cognition, emotion, and behavior. Some behavioral studies investigated how social exclusion affects pain empathy. Conclusions were inconsistent, and there is a lack of clarity in identifying which component of pain empathy is more likely to be affected. To investigate these issues, we used a Cyberball task to manipulate feelings of social exclusion. Two groups (social exclusion and social inclusion) participated in the same pain empathy task while we recorded event-related potentials (ERP) when participants viewed static images of body parts in painful and neutral situations. The results showed early N2 differentiation between painful and neutral pictures in the central regions in both groups. The pattern at the late controlled processing stage was different. Parietal P3 amplitudes for painful pictures were significantly smaller than those for neutral pictures in the social exclusion group; they did not differ in the social inclusion group. We observed a parietal late positive potential (LPP) differentiation between painful and neutral pictures in both groups. LPP amplitudes were significantly smaller in the social exclusion group than those in the social inclusion group for painful stimuli. Our results indicate that social exclusion does not affect empathic responses during the early emotional sharing stage. However, it down-regulates empathic responses at the late cognitive controlled stage, and this modulation is attenuated gradually. The current study provides neuroscientific evidence of how social exclusion dynamically influences pain empathy.

Retrieval-extinction as a reconsolidation-based treatment for emotional disorders:Evidence from an extinction retention test shortly after intervention.

The retrieval-extinction paradigm, a non-invasive memory intervention that is methodologically similar to exposure therapy, has significant clinical application prospects for targeting memory reconsolidation. However, it is difficult to distinguish whether the effect of preventing the return of fear by retrieval-extinction depends upon the reconsolidation-based mechanism or extinction-based mechanism. This study tested extinction retention shortly after intervention to determine whether retrieval-extinction is a reconsolidation-based approach or extinction-based approach as well as exploring the effect of sleep. In our experiment, the effects on fear conditional memory of standard extinction, retrieval-extinction, and extinction-retrieval were compared using the fear test at 3 h, 12 h without a night's sleep, and 12 h with a night's sleep after the intervention. The results showed that standard extinction and extinction-retrieval procedures reduce fear 3 h after intervention, while retrieval-extinction procedure reduces fear 12 h with a night's sleep after the intervention. The results suggest that standard extinction and extinction-retrieval create an extinction memory trace that competes with original memory trace, only retrieval-extinction update the original memory trace through memory reconsolidation. These findings provide solid evidence for the reconsolidation mechanism of the retrieval-extinction paradigm and highlight the effect of sleep on memory reconsolidation.