The influence of encoding strategy on associative memory consolidation across wake and sleep.

Sleep benefits memory consolidation. However, factors present at initial encoding may moderate this effect. Here, we examined the role that encoding strategy plays in subsequent memory consolidation during sleep. Eighty-nine participants encoded pairs of words using two different strategies. Each participant encoded half of the word pairs using an integrative visualization technique, where the two items were imagined in an integrated scene. The other half were encoded nonintegratively, with each word pair item visualized separately. Memory was tested before and after a period of nocturnal sleep (N = 47) or daytime wake (N = 42) via cued recall tests. Immediate memory performance was significantly better for word pairs encoded using the integrative strategy compared with the nonintegrative strategy (P < 0.001). When looking at the change in recall across the delay, there was significantly less forgetting of integrated word pairs across a night of sleep compared with a day spent awake (P < 0.001), with no significant difference in the nonintegrated pairs (P = 0.19). This finding was driven by more forgetting of integrated compared with not-integrated pairs across the wake delay (P < 0.001), whereas forgetting was equivalent across the sleep delay (P = 0.26). Together, these results show that the strategy engaged in during encoding impacts both the immediate retention of memories and their subsequent consolidation across sleep and wake intervals.

Perceived event resolution-rather than time-allows older adults to reduce the negativity of their memories.

In addition to showing greater memory positivity soon after negative events, older adults can be more likely than younger adults to show decreases in memory negativity as events grow more distant. We recently showed that this latter effect was not present when adults were asked to rate memories of the initial phase of the COVID-19 pandemic (March-May 2020): after a short (June/July 2020) and long delay (October/November 2020), older age was associated with greater reflections on positive aspects, but with no difference in negative aspects. We suggested that older adults did not show decreased negativity because the pandemic was still prevalent in their daily lives. The present study examines whether perceived event resolution-rather than time on its own-may be necessary to show age-related decreases in negativity by surveying participants during a time when many may have felt like the pandemic had resolved (Summer 2021). Once again, age was associated with increased ratings of the positive aspects, but at this timepoint, age was also associated with decreased ratings of the negative aspects. These results suggest that older adults may more successfully decrease the negativity of their memories compared to younger adults only when they feel that events have resolved.

The Survivorship Sleep Program (SSP): A synchronous, virtual cognitive behavioral therapy for insomnia pilot program among cancer survivors.

BACKGROUND: For cancer survivors, insomnia is prevalent, distressing, and persists for years if unmanaged. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment yet can be difficult to access and may require modification to address survivorship-specific barriers to sleep. In this 2-phase study, the authors adapted and assessed the feasibility, acceptability, and preliminary effects of synchronous, virtual CBT-I adapted for cancer survivors (the Survivorship Sleep Program [SSP]). METHODS: From April to August 2020, cancer survivors with insomnia (N = 10) were interviewed to refine SSP content and delivery. From October 2020 to March 2021, 40 survivors were recruited for a randomized controlled trial comparing 4 weekly SSP sessions with enhanced usual care (EUC) (CBT-I referral plus a sleep hygiene handout). Feasibility and acceptability were assessed by enrollment, retention, attendance, fidelity, survey ratings, and exit interviews. Insomnia severity (secondary outcome), sleep quality, sleep diaries, and fatigue were assessed at baseline, postintervention, and at 1-month follow-up using linear mixed models. RESULTS: The SSP included targeted content and clinician-led, virtual delivery to enhance patient centeredness and access. Benchmarks were met for enrollment (56% enrolled/eligible), retention (SSP, 90%; EUC, 95%), attendance (100%), and fidelity (95%). Compared with EUC, the SSP resulted in large, clinically significant improvements in insomnia severity (Cohen d = 1.19) that were sustained at 1-month follow-up (Cohen d = 1.27). Improvements were observed for all other sleep metrics except sleep diary total sleep time and fatigue. CONCLUSIONS: Synchronous, virtually delivered CBT-I targeted to cancer survivors is feasible, acceptable, and seems to be efficacious for reducing insomnia severity. Further testing in larger and more diverse samples is warranted.

Age and chronotype influenced sleep timing changes during the first wave of the COVID-19 pandemic.

Social restrictions necessary to reduce the spread of coronavirus disease 2019 (COVID-19) profoundly changed how we socialised, worked and, for students, attended classes. Interestingly, significant sleep pattern shifts occurred in the context of pandemic-related social restrictions. Whether age and chronotype influenced these sleep pattern changes remains poorly understood. In this pre-registered (https://osf.io/4a3fx), web-based study, United States residents reported, in one-time assessments, demographic information, self-reported chronotype using the reduced Morningness-Eveningness Questionnaire, and pre-pandemic and pandemic first wave sleep timing using the Ultrashort Munich Chronotype Questionnaire. Participants reported sleep phase delays, reduced social jetlag (SJL) and reduced social sleep restriction (SSR) during the first wave of the pandemic compared to pre-pandemic. Pandemic-related changes in SJL and SSR varied with participants' age and self-reported chronotype. Young adults reported the greatest reductions in SJL and young adults and individuals with evening chronotypes reported the greatest reductions in SSR. We conclude that these groups may have been the most vulnerable to social-biological sleep timing desynchrony under pre-pandemic social, occupational, and educational schedules.

With age comes well-being: older age associated with lower stress, negative affect, and depression throughout the COVID-19 pandemic.

Objectives: Despite initial concerns about older adult's emotional well-being during the COVID-19 pandemic, reports from the first months of the pandemic suggested that older adults were faring better than younger adults, reporting lower stress, negative affect, depression, and anxiety. In this study, we examined whether this pattern would persist as the pandemic progressed.Method: A convenience sample of 1,171 community-dwelling adults in the United States, ages 18-90, filled out surveys on various metrics of emotional well-being starting in March 2020 and at various time points through April 2021. We created time bins to account for the occurrence of significant national events, allowing us to determine how age would relate to affective outcomes when additional national-level emotional events were overlaid upon the stress of the pandemic.Results: Older age was associated with lower stress, negative affect, and depressive symptomatology, and with higher positive affect, and this effect was consistent across time points measured from March, 2020 through April, 2021. Age was less associated with measures of worry and social isolation, but older adults were more worried about their personal health throughout the pandemic.Conclusion: These results are consistent with literature suggesting that older age is associated with increased resilience in the face of stressful life experiences and show that this pattern may extend to resilience in the face of a prolonged real-world stressor.Supplemental data for this article can be accessed online at https://doi.org/10.1080/13607863.2021.2010183 .

Sleep spectral power correlates of prospective memory maintenance.

Prospective memory involves setting an intention to act that is maintained over time and executed when appropriate. Slow wave sleep (SWS) has been implicated in maintaining prospective memories, although which SWS oscillations most benefit this memory type remains unclear. Here, we investigated SWS spectral power correlates of prospective memory. Healthy young adult participants completed three ongoing tasks in the morning or evening. They were then given the prospective memory instruction to remember to press "Q" when viewing the words "horse" or "table" when repeating the ongoing task after a 12-h delay including overnight, polysomnographically recorded sleep or continued daytime wakefulness. Spectral power analysis was performed on recorded sleep EEG. Two additional groups were tested in the morning or evening only, serving as time-of-day controls. Participants who slept demonstrated superior prospective memory compared with those who remained awake, an effect not attributable to time-of-day of testing. Contrary to prior work, prospective memory was negatively associated with SWS. Furthermore, significant increases in spectral power in the delta-theta frequency range (1.56 Hz-6.84 Hz) during SWS was observed in participants who failed to execute the prospective memory instructions. Although sleep benefits prospective memory maintenance, this benefit may be compromised if SWS is enriched with delta-theta activity.

Higher post-encoding cortisol benefits the selective consolidation of emotional aspects of memory.

Emotional experiences create durable memory traces in the brain, especially when these memories are consolidated in the presence of stress hormones such as cortisol. Although some research suggests cortisol elevation can increase long-term memory for emotional relative to neutral content, the impact of stress and cortisol on the consolidation of emotional and neutral aspects of memories when they are part of the same experience remains unknown. Here, after encoding complex scenes consisting of negative or neutral objects placed on neutral backgrounds, participants were exposed to a psychosocial stressor (or matched control condition) in order to examine the impact of stress and cortisol on early consolidation processes. The next day, once cortisol levels had returned to baseline, specific and gist recognition memory were tested separately for objects and backgrounds. Results indicate that while there was a numerical increase in memory for negative objects in the stress group, higher endogenous cortisol concentrations were specifically associated with decreased memory for the neutral backgrounds originally paired with negative objects. Moreover, across all participants, cortisol levels were positively correlated with the magnitude of the emotional memory trade-off effect. Specifically, while memory for negative objects was preserved, elevated cortisol during early consolidation was associated with decreased memory for neutral backgrounds that were initially paired with negative objects. These memory effects were observed in both the stricter specific measure of memory and the less conservative measure of gist memory. Together, these findings suggest that rather than influencing all aspects of an experience similarly, elevated cortisol during early consolidation selectively preserves what is most emotionally salient and adaptive to remember while allowing the loss of memory for less important neutral information over time.

Dormio: A targeted dream incubation device.

Information processing during sleep is active, ongoing and accessible to engineering. Protocols such as targeted memory reactivation use sensory stimuli during sleep to reactivate memories and demonstrate subsequent, specific enhancement of their consolidation. These protocols rely on physiological, as opposed to phenomenological, evidence of their reactivation. While dream content can predict post-sleep memory enhancement, dreaming itself remains a black box. Here, we present a novel protocol using a new wearable electronic device, Dormio, to automatically generate serial auditory dream incubations at sleep onset, wherein targeted information is repeatedly presented during the hypnagogic period, enabling direct incorporation of this information into dream content, a process we call targeted dream incubation (TDI). Along with validation data, we discuss how Dormio and TDI protocols can serve as tools for controlled experimentation on dream content, shedding light on the role of dreams in the overnight transformation of experiences into memories.

Post-encoding stress enhances mnemonic discrimination of negative stimuli.

Stress influences how we remember emotional events and how these events shape future behaviors. However, the impact of stress on memory specificity for emotional events has yet to be examined. To this end, the present study utilized a mnemonic discrimination task that taxes hippocampal pattern separation, the process of distinguishing between overlapping experiences, thereby allowing us to better understand the mechanisms by which stress affects gist versus detail memory of emotional events. Participants encoded scenes composed of negative or neutral objects placed on neutral backgrounds and then underwent a psychosocial stressor or matched control task. Twenty-four hours later during testing, objects were presented separately, with some identical old objects (targets), some new objects (foils), and some similar but not identical objects (lures). Target recognition was enhanced for negative compared to neutral objects in both the stress and control groups. Interestingly, post-encoding stress selectively enhanced mnemonic discrimination of negative versus neutral objects, which was not the case in the control group. Measures of salivary cortisol revealed a quadratic inverted U relationship between negative mnemonic discrimination and cortisol increase. These findings suggest that moderate cortisol release following stress is associated with enhanced memory precision for negative information.

Effects of post-encoding stress on performance in the DRM false memory paradigm.

Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false memory task) and memory was tested 24 h later. Stress decreased recognition of studied words, while increasing false recognition of semantically related lure words. Moreover, while control subjects remembered true and false words equivalently, stressed subjects remembered more false than true words. These results suggest that stress supports gist memory formation in the DRM task, perhaps by hindering detail-specific processing in the hippocampus.

Psychophysiological arousal at encoding leads to reduced reactivity but enhanced emotional memory following sleep.

While sleep's role in emotional memory processing is gaining increasing support, its effect on emotion regulation remains equivocal. Moreover, little is known about the link between emotional reactivity at the time of encoding and subsequent sleep-based emotional memory consolidation. This study examined whether sleep would potentiate, protect, or depotentiate measures of heart rate and skin conductance in response to scenes containing emotional and neutral objects, and assessed how these measures of reactivity would predict subsequent memory for the objects across delays of sleep and wake. Heart rate deceleration (HRD) and skin conductance response (SCR) data were collected at encoding and recognition. Although HRD and SCR reactivity to objects were depotentiated after a sleep-filled delay, they remained unchanged after a delay containing wakefulness. Moreover, increased arousal responses to negative scenes at encoding as measured by HRD and SCR responses were positively correlated with subsequent memory for the negative objects of scenes, but only in the sleep group. This suggests that larger reactions to negative images at the time of encoding set the stage for the preferential consolidation of these images during a night of sleep. Although arousal responses are often thought to account for emotional enhancement in long-term memory, these findings suggest that both an arousal response at encoding and a subsequent period of sleep are needed to optimize selective emotional memory consolidation.

Examining Measurement Invariance in the Personality Inventory for DSM-5 Brief Form Across Sexual and Gender Minority Status.

The Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Brief Form (PID-5-BF) was developed with an assumption of invariance across sexual and gender minority (SGM) individuals. This assumption has yet to be tested empirically. Using multigroup confirmatory factor analysis, we examined measurement invariance in the PID-5-BF across the SGM status in clinical (N = 1,174; n = 254 SGM) and nonclinical (N = 1,456; n = 151 SGM) samples. Measurement invariance was supported for the PID-5-BF structure, item thresholds, and factor loadings, but not at the item intercept level. SGM individuals endorsed higher negative affectivity, antagonism, disinhibition, and psychoticism domains in both samples. In the clinical sample, adjusting for partial invariance decreased detachment and antagonism levels for SGM persons. In the nonclinical sample, adjusting for partial invariance reduced antagonism disparities in the SGM group, even rendering original group differences null. Our results support the use of the PID-5-BF in SGM populations but indicate that some measurement bias may drive observed disparities in maladaptive trait domains and, in turn, personality disorder diagnosis.

Neuroscience in pictures: 2. Sleep, wakefulness, and mental state biology.

Sleep is a vital restorative process that has occupied our curiosity for millennia. Despite our longstanding research efforts, the biology of sleep and its connection to mental states remains enigmatic. Unsurprisingly, sleep and wakefulness, the fundamental processes between which our mental states oscillate, are inseparable from our physical and mental health. Thus, clinical consideration of sleep impairments warrants a transdiagnostic approach whilst appropriately acknowledging that certain individual disorders (e.g. depression, schizophrenia) may have somewhat distinct sleep disturbances. Moreover, our knowledge of the anatomy and physiology of sleep regulation-albeit limited-forms the foundation for current treatments for sleep difficulties. This pictorial article overviews the core concepts and future of sleep neuroscience and mental state biology for trainees and practitioners in psychiatry and related professions.

Beta spectral power during sleep is associated with impaired recall of extinguished fear.

The failure to retain memory for extinguished fear plays a major role in the maintenance of posttraumatic stress disorder (PTSD), with successful extinction recall necessary for symptom reduction. Disturbed sleep, a hallmark symptom of PTSD, impairs fear extinction recall. However, our understanding of the electrophysiological mechanisms underpinning sleep's role in extinction retention remains underdetermined. We examined the relationship between the microarchitecture of sleep and extinction recall in healthy humans (n = 71, both male and females included) and a pilot study in individuals with PTSD (n = 12). Participants underwent a fear conditioning and extinction protocol over 2 days, with sleep recording occurring between conditioning and extinction. Twenty-four hours after extinction learning, participants underwent extinction recall. Power spectral density (PSD) was computed for pre- and post-extinction learning sleep. Increased beta-band PSD (~17-26 Hz) during pre-extinction learning sleep was associated with worse extinction recall in healthy participants (r = 0.41, p = .004). Beta PSD was highly stable across three nights of sleep (intraclass correlation coefficients > 0.92). Results suggest beta-band PSD is specifically implicated in difficulties recalling extinguished fear.

The Effect of Obstructive Sleep Apnea on Sleep-dependent Emotional Memory Consolidation.

Rationale: A growing body of evidence suggests that sleep is critical for the adaptive processing and consolidation of emotional information into long-term memory. Previous research has indicated that emotional components of scenes particularly benefit from sleep in healthy groups, yet sleep-dependent emotional memory processes remain unexplored in clinical cohorts, including those with obstructive sleep apnea (OSA). This line of research is important as it will add to the understanding of how disrupted sleep in OSA contributes to both impaired cognition and emotion dysregulation. Objectives: To test the hypothesis that individuals with OSA will have impaired sleep-dependent memory consolidation, with the greatest impact being on memory for emotional content. Methods: In this study, a group of newly diagnosed patients with OSA (n = 26; 10 female; average age, 42.5 years) and a matched group of healthy control subjects (n = 24; 13 female; average age, 37 years) were enrolled in the study at Beth Israel Deaconess Medical Center. Participants encoded scenes with negative or neutral foreground objects placed on neutral backgrounds before a night of polysomnographically recorded sleep. In the morning, they completed a recognition test in which old and new scene objects and backgrounds, presented separately and one at a time, were judged as old, new, or similar compared with what had been previously viewed. Results: Patients with OSA had a deficit in recognition memory for the scenes. Overall recognition (the ability to recognize old items as either old or similar) was impaired across all scene elements, both negative and neutral objects and backgrounds, whereas specific recognition (correctly identifying old items as old) was impaired only for negative objects. Across all participants, successful overall recognition correlated positively with sleep efficiency and rapid eye movement (REM) sleep, whereas successful specific memory recognition correlated only with REM sleep. Conclusions: Our findings indicate that fragmented sleep and reduced REM sleep, both hallmarks of OSA, are associated with disruptions in general memory impairment and veridical memory for emotional content, which could alter emotional regulation and contribute to comorbid emotional distress in OSA.

Empathy, memory, and aging during the COVID-19 pandemic.

Recently, there has been increasing attention to the interaction between empathy and memory. During the COVID-19 pandemic, a period when empathy played a key role in people's behaviors, we assessed the relationship between empathy and memory. In this pre-registered report, we used memory accuracy for the number of COVID-19 cases as a measure of recent memory and examined its relationship with trait empathy. Moreover, we investigated whether cognitive vs. affective empathy differently associate with one's memory for the number of COVID-19 cases, given evidence for distinct mechanisms for the two aspects of empathy. Finally, we assessed how age is related to empathy-memory associations. To address these questions, we used the Boston College COVID-19 Dataset, which included surveys assessing dispositional empathy and memory for the number of confirmed COVID-19 cases during the first wave of the pandemic. Empathy was not associated with memory accuracy for the confirmed cases when using an empathy measure that combined both cognitive and affective empathy. However, when using a measure that separately assessed cognitive and affective empathy, only affective empathy, specifically the personal distress subscale, was associated with greater memory accuracy. There was no age-related difference in memory accuracy despite age-related decreases in affective empathy. Results suggest that individuals with greater affective empathy (i.e., greater tendency to feel discomfort by the suffering of others) can have more accurate memory for details of an ongoing empathy-evoking situation. Findings are discussed in the context of motivation and emotional arousal. The current study provides ecological evidence to corroborate the interplay of empathy and memory.

Treatment-related changes in insomnia, anticipatory pleasure, and depression symptoms: A proof-of-concept study with cancer survivors.

OBJECTIVE/BACKGROUND: Cancer survivors have elevated rates of insomnia and depression. Insomnia increases risk for depression onset, and the Integrated Sleep and Reward (ISR) Model suggests that impairments in reward responding (e.g., ability to anticipate and/or experience pleasure) plays a central role in this relationship. Cognitive behavioral therapy for insomnia (CBT-I) is efficacious for treating chronic insomnia and reducing depression in cancer survivor populations. The effects of CBT-I on anticipatory and consummatory pleasure are theoretically and clinically meaningful, yet remain unexamined. PATIENTS/METHODS: This secondary analysis of a pilot RCT (N = 40 cancer survivors with insomnia) explicated changes in anticipatory and consummatory pleasure and depression symptoms following a 4-session, synchronous, virtual CBT-I program versus enhanced usual care (referral to a behavioral sleep medicine clinic + sleep hygiene handout). Linear mixed models examined changes in anticipatory and consummatory pleasure and depression symptoms as predictors of changes in insomnia severity from baseline to post-intervention and 1-month follow-up. RESULTS: CBT-I buffered against deterioration in anticipatory pleasure but not consummatory pleasure or depression symptoms. Across conditions, increased anticipatory pleasure was associated with insomnia reduction through 1-month follow-up, even after adjusting for changes in depression symptoms. CONCLUSION: CBT-I may improve reward processing deficits in cancer survivors with insomnia. Findings provide support for the ISR Model and implicate pleasure as an important target for insomnia and depression.

Moral decision-making during the COVID-19 pandemic: Associations with age, negative affect, and negative memory.

The COVID-19 pandemic provided the opportunity to determine whether age-related differences in utilitarian moral decision-making during sacrificial moral dilemmas extend to non-sacrificial dilemmas in real-world settings. As affect and emotional memory are associated with moral and prosocial behaviors, we also sought to understand how these were associated with moral behaviors during the 2020 spring phase of the COVID-19 pandemic in the United States. Older age, higher negative affect, and greater reports of reflecting on negative aspects of the pandemic were associated with higher reported purchase of hard-to-find goods, while older age and higher negative affect alone were associated with higher reported purchase of hard-to-find medical supplies. Older age was associated with what appeared at first to be non-utilitarian moral behaviors with regard to the purchasing of these supplies; However, they also reported distributing these goods to family members rather than engaging in hoarding behaviors. These findings suggest that advancing age may be associated with engagement in utilitarian moral decision-making in real-world settings more than the sacrificial moral decision-making literature would suggest.

Investigating the effects of sleep and sleep loss on the different stages of episodic emotional memory: A narrative review and guide to the future.

For two decades, sleep has been touted as one of the primary drivers for the encoding, consolidation, retention, and retrieval of episodic emotional memory. Recently, however, sleep's role in emotional memory processing has received renewed scrutiny as meta-analyses and reviews have indicated that sleep may only contribute a small effect that hinges on the content or context of the learning and retrieval episodes. On the one hand, the strong perception of sleep's importance in maintaining memory for emotional events may have been exacerbated by publication bias phenomena, such as the "winner's curse" and "file drawer problem." On the other hand, it is plausible that there are sets of circumstances that lead to consistent and reliable effects of sleep on emotional memory; these circumstances may depend on factors such as the placement and quality of sleep relative to the emotional experience, the content and context of the emotional experience, and the probes and strategies used to assess memory at retrieval. Here, we review the literature on how sleep (and sleep loss) influences each stage of emotional episodic memory. Specifically, we have separated previous work based on the placement of sleep and sleep loss in relation to the different stages of emotional memory processing: (1) prior to encoding, (2) immediately following encoding during early consolidation, (3) during extended consolidation, separated from initial learning, (4) just prior to retrieval, and (5) post-retrieval as memories may be restructured and reconsolidated. The goals of this review are three-fold: (1) examine phases of emotional memory that sleep may influence to a greater or lesser degree, (2) explicitly identify problematic overlaps in traditional sleep-wake study designs that are preventing the ability to better disentangle the potential role of sleep in the different stages of emotional memory processing, and (3) highlight areas for future research by identifying the stages of emotional memory processing in which the effect of sleep and sleep loss remains under-investigated. Here, we begin the task of better understanding the contexts and factors that influence the relationship between sleep and emotional memory processing and aim to be a valuable resource to facilitate hypothesis generation and promote important future research.

How the 2020 US Presidential election impacted sleep and its relationship to public mood and alcohol consumption.

OBJECTIVES: Major sociopolitical events can influence the general public's affective state and other affect-related processes, such as sleep. Here, we investigated the extent that the 2020 US presidential election impacted sleep, public mood, and alcohol consumption. We also explored the relationship between affect and sleep changes during the peak period of election stress. PARTICIPANTS: US-residing (n = 437) and non-US-residing (n = 106) participants were recruited online for participation in the study. METHODS: A non-representative, convenience sample responded to daily assessments of their affect, sleep, and alcohol consumption during a baseline period (October 1-13, 2020) and in the days surrounding the 2020 US Election (October 30-November 12, 2020). RESULTS: Analyses determined changes within and between US and non-US participants. Election Day evoked significantly reduced sleep amount and efficiency, coupled with heightened stress, negative affect, and increased alcohol use. While US participants were significantly more impacted in a number of domains, non-US participants also reported reduced sleep and greater stress compared to baseline. Across participants, disrupted sleep on Election Night correlated with changes in emotional well-being and alcohol consumption on Election Day. CONCLUSION: These results suggest that major sociopolitical events can have global impacts on sleep that may interact with significant fluctuations in public mood and well-being. Further, while the largest impact is on the local population, these results suggest that the effects can extend beyond borders. These findings highlight the potential impact of future sociopolitical events on public well-being.