Aversive memories can be weakened during human sleep via the reactivation of positive interfering memories.

Recollecting painful or traumatic experiences can be deeply troubling. Sleep may offer an opportunity to reduce such suffering. We developed a procedure to weaken older aversive memories by reactivating newer positive memories during sleep. Participants viewed 48 nonsense words each paired with a unique aversive image, followed by an overnight sleep. In the next evening, participants learned associations between half of the words and additional positive images, creating interference. During the following non-rapid-eye-movement sleep, auditory memory cues were unobtrusively delivered. Upon waking, presenting cues associated with both aversive and positive images during sleep, as opposed to not presenting cues, weakened aversive memory recall while increasing positive memory intrusions. Substantiating these memory benefits, computational modeling revealed that cueing facilitated evidence accumulation toward positive affect judgments. Moreover, cue-elicited theta brain rhythms during sleep predominantly predicted the recall of positive memories. A noninvasive sleep intervention can thus modify aversive recollection and affective responses.

Sense of own body shapes neural processes of memory encoding and reinstatement.

How is the fundamental sense of one's body, a basic aspect of selfhood, incorporated into memories for events? Disrupting bodily self-awareness during encoding impairs functioning of the left posterior hippocampus during retrieval, which implies weakened encoding. However, how changes in bodily self-awareness influence neural encoding is unknown. We investigated how the sense of body ownership, a core aspect of the bodily self, impacts encoding in the left posterior hippocampus and additional core memory regions including the angular gyrus. Furthermore, we assessed the degree to which memories are reinstated according to body ownership during encoding and vividness during retrieval as a measure of memory strength. We immersed participants in naturalistic scenes where events unfolded while we manipulated feelings of body ownership with a full-body-illusion during functional magnetic resonance imaging scanning. One week later, participants retrieved memories for the videos during functional magnetic resonance imaging scanning. A whole brain analysis revealed that patterns of activity in regions including the right hippocampus and angular gyrus distinguished between events encoded with strong versus weak body ownership. A planned region-of-interest analysis showed that patterns of activity in the left posterior hippocampus specifically could predict body ownership during memory encoding. Using the wider network of regions sensitive to body ownership during encoding and the left posterior hippocampus as separate regions-of-interest, we observed that patterns of activity present at encoding were reinstated more during the retrieval of events encoded with strong body ownership and high memory vividness. Our results demonstrate how the sense of physical self is bound within an event during encoding, which facilitates reactivation of a memory trace during retrieval.

What makes an event significant: an fMRI study on self-defining memories.

Self-defining memories are highly significant personal memories that contribute to an individual's life story and identity. Previous research has identified 4 key subcomponents of self-defining memories: content, affect, specificity, and self-reflection. However, these components were not tested under functional neuroimaging. In this study, we first explored how self-defining memories distinguish themselves from everyday memories (non-self-defining) through their associated brain activity. Next, we evaluated the different self-defining memory subcomponents through their activity in the underlying brain system. Participants recalled both self-defining and non-self-defining memories under functional MRI and evaluated the 4 subcomponents for each memory. Multivoxel pattern analysis uncovered a brain system closely related to the default mode network to discriminate between self-defining and non-self-defining memories. Representational similarity analysis revealed the neural coding of each subcomponent. Self-reflection was coded mainly in the precuneus, middle and inferior frontal gyri, and cingulate, lateral occipital, and insular cortices. To a much lesser extent, content coding was primarily in the left angular gyrus and fusiform gyrus. No region was found to represent information on affect and specificity. Our findings highlight the marked difference in brain processing between significant and non-significant memories, and underscore self-reflection as a predominant factor in the formation and maintenance of self-defining memories, inviting a reassessment of what constitutes significant memories.

Dopant Engineering of Hafnia-Based Ferroelectrics for Long Data Retention and High Thermal Stability.

Hafnia-based ferroelectrics have gained much attention because they can be used in highly scaled, advanced complementary metal-oxide semiconductor (CMOS) memory devices. However, thermal stability should be considered when integrating hafnia-based ferroelectric transistors in advanced CMOS devices, as they can be exposed to high-temperature processes. This work proposed that doping of Al in hafnia-based ferroelectric material can lead to high thermal stability. A ferroelectric capacitor based on Al-doped hafnia, which can be used for one-transistor-one-capacitor applications, exhibits stable operation even after annealing at 900 °C. Moreover, it demonstrates that the ferroelectric transistors based on Al-doped hafnia for one-transistor applications, such as ferroelectric NAND, retain their memory states for 10 years at 100 °C. This study presents a practical method to achieve thermally stable ferroelectric memories capable of enduring high-temperature processes and operation conditions.

Temporal association activates projections from the perirhinal cortex and ventral CA1 to the prelimbic cortex and from the prelimbic cortex to the basolateral amygdala.

In trace fear conditioning, the prelimbic cortex exhibits persistent activity during the interval between the conditioned and unconditioned stimuli, which maintains a conditioned stimulus representation. Regions cooperating for this function or encoding the conditioned stimulus before the interval could send inputs to the prelimbic cortex, supporting learning. The basolateral amygdala has conditioned stimulus- and unconditioned stimulus-responsive neurons, convergently activated. The prelimbic cortex could directly project to the basolateral amygdala to associate the transient memory of the conditioned stimulus with the unconditioned stimulus. We investigated the neuronal circuit supporting temporal associations using contextual fear conditioning with a 5-s interval, in which 5 s separates the contextual conditioned stimulus from the unconditioned stimulus. Injecting retrobeads, we quantified c-Fos in prelimbic cortex- or basolateral amygdala-projecting neurons from 9 regions after contextual fear conditioning with a 5-s interval or contextual fear conditioning, in which the conditioned and unconditioned stimuli overlap. The contextual fear conditioning with a 5-s interval activated ventral CA1 and perirhinal cortex neurons projecting to the prelimbic cortex and prelimbic cortex neurons projecting to basolateral amygdala. Both fear conditioning activated ventral CA1 and lateral entorhinal cortex neurons projecting to basolateral amygdala and basolateral amygdala neurons projecting to prelimbic cortex. The perirhinal cortex â†’ prelimbic cortex and ventral CA1 â†’ prelimbic cortex connections are the first identified prelimbic cortex afferent projections participating in temporal associations. These results help to understand time-linked memories, a process required in episodic and working memories.

An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study.

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Inducing emotionally negative nonbelieved memories using negative pictures.

Memories that can be recalled but are no longer believed are termed nonbelieved memories. The current studies examined the creation of emotionally negative nonbelieved memories after viewing negatively valenced pictures. In both experiments, participants took part in two sessions. In Session 1, after being presented with a set of neutral and negative pictures, participants had to rate their emotional state. One week later, in Session 2, participants had to complete a recognition task to identify pictures that had appeared during the previous session. During this task, participants' memories for some pictures were challenged by telling them that their answers were incorrect in order to evoke nonbelieved memories. The experimental procedure was successful in creating nonbelieved memories in the participants. Specifically, in Experiment 1 (N = 35), we induced nonbelieved true memories for both negative and neutral pictures. We found a significant decrease in both belief and recollection after the challenge, with the change in belief being twice as large as the change in recollection. In Experiment 2 (N = 43), we successfully induced both nonbelieved true and false memories for negative pictures. Again, the reduction of belief was significantly greater than that of recollection. In general, participants evinced better memory for negative pictures, but following challenges people were just as likely to accept false social feedback and change their memories regarding other types of pictures. In both experiments, our challenges did not lead to notable changes in emotional state. In general, our findings show that emotionally negative nonbelieved memories can be successfully evoked in an experimental setting.

How do early affiliative memories explain body image shame? A 12-month longitudinal study in adolescent girls.

OBJECTIVE: This study aimed to explain adolescent girls' body image shame across a 12- month longitudinal design, and its relationship with early parental memories of warmth and safeness and fear of receiving compassion from others. DESIGN AND METHODS: Participants included 231 adolescent girls, who completed self-report measures at three different periods: baseline (W1), 6-month follow-up (W2), and 12-month follow-up (W3). Descriptive and correlational analyses were performed, and differences between participants at the different waves were explored through repeated measures ANOVA. A cross-lagged panel model tested the mediational effect of fears of receiving compassion on the association between early affiliative memories (W1) and body image shame (W3). RESULTS: ANOVA results found significant differences throughout time in memories of warmth and safeness (tending to diminish) and in body image shame (tending to rise). Correlation analysis revealed that all variables were significantly associated in the expected directions, across the three waves. Finally, path analysis revealed that early affiliative parental memories (in W1) had a direct effect on body image shame (in W3), through the fear of receiving compassion from others (in W2), accounting for 85% of body image shame's variance (W3). CONCLUSIONS: These findings indicate that the lack of early affiliative memories often leads to the development of defensive mechanisms such as fears of receiving compassion from others which in turn can foster isolation and distant relationships, enhancing feelings of inferiority and inadequacy, which in female adolescents can emerge centered on body image - body image shame. This study further highlights the importance of prevention and intervention strategies based on compassion to specifically target fears of receiving compassion from others, in adolescent girls dealing with feelings of inferiority and shame regarding their body.

Recovered memories in psychotherapy: a survey of practicing psychotherapists in Germany.

We report on a survey of 258 psychotherapists from Germany, focusing on their experiences with memory recovery in general, suggestive therapy procedures, evaluations of recovered memories, and memory recovery in training and guidelines. Most therapists (78%) reported instances of memory recovery encompassing negative and positive childhood experiences, but usually in a minority of patients. Also, most therapists (82%) reported to have held assumptions about unremembered trauma. Patients who held these beliefs were reported by 83% of the therapists. Both therapist and patient assumptions reportedly occurred in a minority of cases. Furthermore, 35% of participants had used therapeutic techniques at least once to recover presumed trauma memories. Only 10% reported assuming trauma in most patients and recovering purported memories in a majority of the attempts. A fifth believed memory recovery was a task of psychotherapy. This belief correlated with trauma assumptions, memory recovery attempts, and recovery frequency. Psychodynamic therapists more often reported to assume trauma behind symptoms and agreed more with problematic views on trauma and memory. No differences showed regarding suggestive behaviour in therapy. Most participants expressed interest in receiving support on dealing with memory recoveries. This interest should be taken up, ideally during therapist training.

Young adults' personal and relationship memories: recollections of self, siblings, and family.

We investigated the phenomenological and narrative characteristics of young adults' self- and other-related memories within the context of significant relationships. We also examined whether participants' gender and/or gender concordance between participants and their siblings was associated with autobiographical memory characteristics. We collected data from 108 college students who had only one sibling. All participants provided narratives in response to three memory prompts (i.e., self-related, sibling-related, and family-related) and rated their memories along dimensions such as significance, emotional valence, clarity etc. The narratives were coded on thematic content, transformativeness, mentions of others, and event type dimensions. Results revealed differences between self-related memories and sibling- and family-related memories across several dimensions. However, sibling-related and family-related memories were mostly similar to each other. No statistically significant gender or gender concordance differences were observed. Further exploratory analysis showed that memory narratives describing extended events were more transformative than single event narratives. The findings enhance our understanding about the self-in-relation to others through relationship memories.

The reminiscence bump and the self: evidence from five studies on positive and negative memories.

A plethora of studies have shown that people persistently remember public and personal events experienced during adolescence and early adulthood, particularly with a positive valence. In five studies, we investigate the reminiscence bump (RB) for positive and negative memories of public events (Studies 1 and 2), private events (Study 3), music-related events (Study 4), and cross-cultural memory differences (i.e., China and US) (Study 5). Participants retrieved either one positive or one negative memory, indicated their Age of Encoding, and provided secondary measures, i.e., memory vividness and rehearsal (Studies 1 and 3) and emotional intensity (Studies 2 and 4). About 10,000 memories were collected and positive memories appeared generally older than negative recollections, but the RB emerged for both positive and negative memories. Furthermore, the peak was earlier for positive memories of public events (<15 years old) than for negative memories (20-40 years), while no differences were found for private events or music-related experiences (15-25 years). Chinese had their RB later than US respondents. Finally, autobiographical recollections have moderate to low associations with secondary measures of phenomenological features of memory. These findings are consistent with the identity-formation theory, providing additional and important information on the development of the Self.

Autobiographical phenomenology of memories of fiction.

Most autobiographical memories are based on real-life experiences, but memories of fiction have many similarities to real-life autobiographical memories. However, the phenomenological nature of this similarity, the potential differences between media types, and the role of individual differences need further investigation. Based on previous findings, we expected differences between media types on emotional intensity, sensory vividness, and confidence about the recall. To provide insight into these issues, we collected one real-life autobiographical memory and one memory of fiction (book, film, or video game) from 291 participants. We asked them to rate their memories phenomenologically. The participants also provided information regarding their motivations for engaging with fictional stories. Our results show phenomenological differences in several dimensions between media types and differences in the similarity of media types to real-life memories. While absorption seems to be a good predictor for immersion, escapism tendency is a motivation to engage with fiction frequently.

Self-reported sensibility to bodily signals predicts individual differences in autobiographical memory: an exploratory study.

Recent theoretical perspectives have advanced that autobiographical memory processes are supported by interoception, the perception of internal bodily sensations. Yet, this relationship remains largely underexplored. The present study addressed this critical gap in the literature by systematically investigating the association between self-reported Interoceptive Sensibility and various individual differences measures of autobiographical memory. In Study 1, using a correlational approach in a large sample of participants (N = 247), we identified significant correlations between standardised measures of interoception and the general experience of autobiographical memory and the frequency of involuntary mental time travel. These associations remained significant even after controlling for potential confounding factors in terms of age, gender, and trait affectivity, underscoring their robustness. Study 2 replicated and extended the associations identified in Study 1 in another large participant sample (N = 257), further validating them by accounting for the potential confounding effect of well-being. Our findings demonstrate that individuals' ability to perceive and understand bodily signals robustly relates to how they experience autobiographical memories. By adopting an exploratory approach based on individual differences, our results provide novel and concrete insights into the association between interoception and autobiographical memory, providing a strong foundation for future investigations into the causal mechanisms connecting these two constructs.

COVID-19 memories young adults may share: exploring event properties and motivations for transmission.

The COVID-19 pandemic has left an enduring mark on human history. This study investigates the intergenerational transmission of COVID-19 memories through a unique approach involving 49 participants aged 18-30. Specifically, participants were prompted to share a COVID-19 memory they would choose to transmit to their future children. Furthermore, participants provided reasons for selecting that particular memory, utilising a memory functions scale and open-ended responses. Applying Transition Theory, we examined the transitional impact, event importance, previous rehearsal, and valence of reported memories. Results revealed that 88% of memories revolve around distinctive events inducing psychological and material changes. Perceived as significant, negative, and transitional, these memories are predominantly public in nature. Predictors of event importance include previous rehearsal and psychological change. Participants share memories primarily for directive purposes, intending to inform future generations. The results imply that transitions not only organise personal memories but may also direct and shape memories for public events.

In my life: memory, self and The Beatles.

In a large-scale study, we asked people for their memories of The Beatles. Over four thousand respondents completed an online questionnaire. The memory could be related to a song, album, event, TV, film, or even a personal encounter. Respondents judged the age at which the event remembered had occurred and rated the memory for vividness, emotional intensity, valence and rehearsal. We found 38% of the memories were classified as "seeing The Beatles live", 25% "buying Beatles music", 20% "love of The Beatles" and 17% of the memories were "listening to Beatles songs with other people" - what we refer to as cascading memories. Among the younger respondents (aged 26 and under), 84% of the memories were cascading in nature. The memories dated to what we term the "self-defining period" in autobiographical memory (previously termed "the reminiscence bump"), with a mean age-at-encoding of 13.6 years, which is consistent with other studies of memories associated with music. We propose that these memories reflect the formation of generational identity [Mannheim, K. (1952). The problem of generations. In K. Mannheim (Ed.), Essays on the sociology knowledge (pp. 276-321). Routledge & Keegan Paul].

Retracted memories in the general population: are there differences between eastern and western countries?

The main purpose of the current studies was to examine retracted experiences in the general population from various cultural backgrounds. More specifically, in two studies, we examined the details of memory retraction experiences, the reasons for retraction, and the outcomes of retraction in participants from China and other countries, mainly the United States of America. It was found that memory retraction experiences appeared to be quite common. In the sample of Chinese participants (Study 1: N = 1380), 50.58% reported at least one such an experience, whereas in respondents from other countries (Study 2; N = 425), a significantly lower but still substantial prevalence rate of 35% was found. In general, the retracted memories predominantly involved positive events and some respondents experienced pressure during the withdrawal. Social feedback and event plausibility were the two main reasons for the withdrawal. Compared to recollection scores, belief scores decreased significantly after withdrawal, and some respondents even formed nonbelieved memories. After retracting the memories, most respondents felt they gained benefits (e.g., they had resolved a psychological problem that had bothered them for years). These studies give us a more general understanding of retracted memory experiences in the general population.

Early childhood memories of individuals convicted of sexual offences.

This study used innovative transdisciplinary methods to describe the nature and extent of early childhood memories recalled by 84 adults convicted of sexual offences. The timing of the memories, level of detail recalled and way memories were recollected were largely consistent with extant memory research. One important finding, however, was that more than 30% of our participants recalled particularly traumatic and distressing childhood experiences - a much higher proportion than previously observed in nonoffending samples. The extent to which these memories laid the foundation for subsequent emotional content and feature in the evolution of cognitive schemata is not yet well understood. With that in mind, we consider the implications of our findings for the event centrality in self-narratives. We recommend the inclusion of treatment modalities that maximise as yet unrecognised and undervalued narrative inclinations and story-telling abilities of a complicated population of individuals with rich lived experience that stands to benefit greatly from such approaches.

On the retrieval of earliest memories.

Earliest memories were examined with respect to recollection type (i.e., remember-know), retrieval type (i.e., direct-generative), retrieval speed, and memory fluency (i.e., phonemic, semantic, and autobiographical). A total of 137 young adults (94 females; Mage = 20.47, SDage = 1.57) reported their earliest memories and specified their recollection and retrieval types for reported memories. They further dated their recollections by reporting the age at event, rated event characteristics and completed the phonemic, semantic, and autobiographical memory fluency tasks. Remembered and known earliest memories were similar in retrieval speed, but remembered memories were more prevalent. For retrieval type, direct and generative retrieval were similar in prevalence, but direct retrieval was faster in recalling the earliest memories. Directly retrieved memories were dated earlier than generated ones, but no such pattern in dating was observed for remember-know distinction. In terms of memory fluency, none of the three fluency tasks predicted the retrieval speed, recollection and retrieval type. For event characteristics, significant differences were observed only for vividness and rehearsal for both retrieval and recollection type. The present study is the first to explore recollection and retrieval type, retrieval speed, memory fluency together with dating and event characteristics in the context of earliest memories.

Alleged false accusations of abuse: characteristics, consequences, and coping.

ABSTRACTWe have very little knowledge about the characteristics and consequences of false abuse accusations. Sixty-one members of a German support organisation for allegedly falsely accused individuals provided information about themselves, the accuser, the accusation, the consequences of the allegation, and their coping strategies. The majority of respondents were male (90%), accused of sexual abuse (89%), and a parent of the accuser (71%). The initial allegations were frequently (72%) associated with the accuser undergoing psychotherapy. The consequences for the accused were psychological, physiological, familial, job-related, personal, and legal in nature. These included a loss of contact (98%), altered family dynamics (92%), depressive symptoms (48%), and problems focussing at work (44%). Eleven accused (18%) faced legal prosecution, but none of them were charged. Frequent strategies to cope with the allegation included contacting the victim support organisation (100%), seeking therapy (51%), contacting counselling centres (43%) and other victim support organisations (23%). Most of the accused felt supported by their environment (84%). Supporting and elaborating upon previous studies, this study exposes the potential consequences of alleged false accusations.

Direct retrieval as a theory of involuntary autobiographical memories: evaluation and future directions.

I evaluate the conception of direct retrieval as originally formulated in the Self-Memory System model (Conway & Pleydell-Pearce [2000]. The construction of autobiographical memories in the self-memory system. Psychological Review, 107(2), 261-288. https://doi.org/10.1037/0033-295X.107.2.261). In the hierarchical memory organisation proposed in the Self-Memory System model, direct retrieval is described as a bottom-up associative process. While its theoretical role within this model is clear, systematic empirical examination of direct retrieval, viewed as a natural and observable phenomenon, has been hampered by inconsistent operationalisations. Here, I suggest that direct retrieval should be treated as a theoretical concept, aiming at explaining the phenomenon of involuntary (spontaneously arising) autobiographical memories. I evaluate predictions derived from the concept of direct retrieval against findings on involuntary autobiographical memories obtained over the past 25 years. Most of these predictions are consistent with the evidence, notably, the enhanced episodic specificity and constructive nature of involuntary autobiographical memories. However, the theory also has critical limitations. It did not predict the frequent occurrence of involuntary recollections in daily life, exceeding the prevalence of voluntary memories. Additionally, it overlooked the early emergence of spontaneously arising event memories in ontogenesis and their presence in other species, such as great apes. Future advancements of the Self-Memory System model should integrate evolutionary perspectives to address these limitations.