Benefits of collaborative remembering in older and younger couples: the role of conversation dynamics and gender.

We experimentally explored whether and how conversation dynamics would benefit collaborative remembering in intimate couples over time. To this end, we ran a study with a three-factor mixed design with relationship type (couples vs. strangers) and age (older adults vs. younger adults) as between-participants variables, and remembering condition (collaborative vs. individual) as a within-participants variable. Thirty pairs of intimate couples (fifteen long-term relationship older couples, fifteen short-term relationship younger couples) and thirty pairs of corresponding stranger-pairs (including older strangers and younger strangers) were compared with respect to recall accuracy and conversation dynamics, specifically considering the role of gender. Results revealed significant collaborative facilitation only in older couples. Also, females' communication behaviours facilitated males' collaborative remembering performance only in older (vs. younger) couples. In addition, a gender-specific pattern of shifts from the individual to collaborative context emerged only in older couple (vs. strangers). The findings are consistent with the notion that a longer experience of collaboration and more effective conversation dynamics allow older (vs. younger) couples to perform better at collaborative remembering. We discuss processes underlying the observed gender differences, and the social and motivational implications of collaborative remembering.

A Generalizable Multivariate Brain Pattern for Interpersonal Guilt.

Feeling guilty when we have wronged another is a crucial aspect of prosociality, but its neurobiological bases are elusive. Although multivariate patterns of brain activity show promise for developing brain measures linked to specific emotions, it is less clear whether brain activity can be trained to detect more complex social emotional states such as guilt. Here, we identified a distributed guilt-related brain signature (GRBS) across two independent neuroimaging datasets that used interpersonal interactions to evoke guilt. This signature discriminated conditions associated with interpersonal guilt from closely matched control conditions in a cross-validated training sample (N = 24; Chinese population) and in an independent test sample (N = 19; Swiss population). However, it did not respond to observed or experienced pain, or recalled guilt. Moreover, the GRBS only exhibited weak spatial similarity with other brain signatures of social-affective processes, further indicating the specificity of the brain state it represents. These findings provide a step toward developing biological markers of social emotions, which could serve as important tools to investigate guilt-related brain processes in both healthy and clinical populations.

Common and differential neural networks of emotion regulation by Detachment, Reinterpretation, Distraction, and Expressive Suppression: a comparative fMRI investigation.

Emotions are an indispensable part of our mental life. The term emotion regulation refers to those processes that influence the generation, the experience and the expression of emotions. There is a great variety of strategies to regulate emotions efficiently, which are used in daily life and that have been investigated by cognitive neuroscience. Distraction guides attention to a secondary task. Reinterpretation, a variant of cognitive reappraisal, works by changing the meaning of an emotional stimulus. Detachment, another reappraisal strategy, refers to distancing oneself from an emotional stimulus, thereby reducing its personal relevance. Expressive Suppression modifies the behavioral or physiological response to an emotional stimulus. These four strategies are not equally effective in terms of emotion regulation success and have been shown to partly rely on different neuronal systems. Here, we compare for the first time the neural mechanisms of these typical strategies directly in a common functional magnetic resonance imaging (fMRI) paradigm of downregulation of negative emotions. Our results indicate that three of those strategies (Detachment, Expressive Suppression and Distraction) conjointly increase brain activation in a right prefronto-parietal regulation network and significantly reduce activation of the left amygdala. Compared to the other regulation strategies, Reinterpretation specifically recruited a different control network comprising left ventrolateral prefrontal cortex and orbitofrontal gyrus and was not effective in downregulation of the amygdala. We conclude that Detachment, Distraction and Expressive Suppression recruit very similar emotion regulation networks, whereas Reinterpretation is associated with activation of a qualitatively different network, making this regulation strategy a special one. Notably, Reinterpretation also proved to be the least effective strategy in neural terms, as measured by downregulation of amygdala activation.

Biased memory retrieval in the service of shared reality with an audience: The role of cognitive accessibility.

After communicators have tuned a message about a target person's behaviors to their audience's attitude, their recall of the target's behaviors is often evaluatively consistent with their audience's attitude. This audience-congruent recall bias has been explained as the result of the communicators' creation of a shared reality with the audience, which helps communicators to achieve epistemic needs for confident judgments and knowledge. Drawing on the "Relevance Of A Representation" (ROAR) model of cognitive accessibility from motivational truth relevance, we argue that shared reality increases the accessibility of information consistent (vs. inconsistent) with the audience's attitude. We tested this prediction with a novel reaction time task in three experiments employing the saying-is-believing paradigm. Faster reactions to audience-consistent (vs. audience-inconsistent) information were found for trait information but not for behavioral information. Thus, an audience-congruent accessibility bias emerged at the level at which impressions and judgments of other persons are typically organized. Consistent with a shared-reality account, the audience-consistent accessibility bias correlated with experienced shared reality with the audience about the target person and with epistemic trust in the audience. These findings support the view that the creation of shared reality with an audience triggers a basic cognitive mechanism that facilitates the retrieval of audience-congruent (vs. audience-incongruent) trait information about a target person. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Patient-reported effects of hospital-wide implementation of shared decision-making at a university medical centre in Germany: a pre-post trial.

OBJECTIVES: To evaluate the feasibility and effectiveness of the SHARE TO CARE (S2C) programme, a complex intervention designed for hospital-wide implementation of shared decision-making (SDM). DESIGN: Pre-post study. SETTING: University Hospital Schleswig-Holstein (UKSH), Kiel Campus. PARTICIPANTS: Healthcare professionals as well as inpatients and outpatients from 22 departments of the Kiel Campus of UKSH. INTERVENTIONS: The S2C programme is a comprehensive implementation strategy including four core modules: (1) physician training, (2) SDM support training for and support by nurses as decision coaches, (3) patient activation and (4) evidence-based patient decision aid development and integration into patient pathways. After full implementation, departments received the S2C certificate. MAIN OUTCOME MEASURES: In this paper, we report on the feasibility and effectiveness outcomes of the implementation. Feasibility was judged by the degree of implementation of the four modules of the programme. Outcome measures for effectiveness are patient-reported experience measures (PREMs). The primary outcome measure for effectiveness is the Patient Decision Making subscale of the Perceived Involvement in Care Scale (PICSPDM). Pre-post comparisons were done using t-tests. RESULTS: The implementation of the four components of the S2C programme was able to be completed in 18 of the 22 included departments within the time frame of the study. After completion of implementation, PICSPDM showed a statistically significant difference (p<0.01) between the means compared with baseline. This difference corresponds to a small to medium yet clinically meaningful positive effect (Hedges' g=0.2). Consistent with this, the secondary PREMs (Preparation for Decision Making and collaboRATE) also showed statistically significant, clinically meaningful positive effects. CONCLUSIONS: The hospital-wide implementation of SDM with the S2C-programme proved to be feasible and effective within the time frame of the project. The German Federal Joint Committee has recommended to make the Kiel model of SDM a national standard of care.

Psychotherapy motivation in refugees: The role of alexithymia, stigmatization, self-esteem, and psychotherapy expectations.

OBJECTIVE: Despite elevated mental health problems, refugees tend to hold more negative attitudes toward psychological help seeking than residents of receiving countries. Therefore, we examined variables expected to be related to different aspects of psychotherapy motivation (psychological distress, knowledge about therapy, and denial of psychological helplessness) in 202 German residents and 200 refugees in Germany. METHOD: Participants completed measures of psychotherapy motivation, together with alexithymia, stigmatization toward help seeking, self-esteem, and expectations of therapy as variables with an expected relationship with psychotherapy motivation. RESULTS: Refugees reported higher scores of psychological distress, more denial of psychological helplessness, and less knowledge about psychotherapy than residents. Refugees further reported higher levels of alexithymia and lower expectations for interpersonal and intrapersonal change in therapy compared to residents. In a pathway model, alexithymia, perceived stigmatization, self-esteem, and expectations for interpersonal changes emerged as critical variables associated with psychotherapy motivation. Alexithymia and expectations for interpersonal change partly accounted for group differences of reduced psychotherapy motivation in refugees. CONCLUSIONS: We discuss implications for practice and future research with respect to reducing treatment barriers and providing culturally-sensitive treatments for refugees suffering from psychological distress. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Increased alpha (8-12 Hz) activity during slow wave sleep as a marker for the transition from implicit knowledge to explicit insight.

The number reduction task (NRT) allows us to study the transition from implicit knowledge of hidden task regularities to explicit insight into these regularities. To identify sleep-associated neurophysiological indicators of this restructuring of knowledge representations, we measured frequency-specific power of EEG while participants slept during the night between two sessions of the NRT. Alpha (8-12 Hz) EEG power during slow wave sleep (SWS) emerged as a specific marker of the transformation of presleep implicit knowledge to postsleep explicit knowledge (ExK). Beta power during SWS was increased whenever ExK was attained after sleep, irrespective of presleep knowledge. No such EEG predictors of insight were found during Sleep Stage 2 and rapid eye movement sleep. These results support the view that it is neuronal memory reprocessing during sleep, in particular during SWS, that lays the foundations for restructuring those task-related representations in the brain that are necessary for promoting the gain of ExK.

Guilt-specific processing in the prefrontal cortex.

Guilt is a central moral emotion due to its inherent link to norm violations, thereby affecting both individuals and society. Furthermore, the nature and specificity of guilt is still debated in psychology and philosophy, particularly with regard to the differential involvement of self-referential representations in guilt relative to shame. Here, using functional magnetic resonance imaging (fMRI) in healthy volunteers, we identified specific brain regions associated with guilt by comparison with the 2 most closely related emotions, shame and sadness. To induce high emotional intensity, we used an autobiographical memory paradigm where participants relived during fMRI scanning situations from their own past that were associated with strong feelings of guilt, shame, or sadness. Compared with the control emotions, guilt episodes specifically recruited a region of right orbitofrontal cortex, which was also highly correlated with individual propensity to experience guilt (Trait Guilt). Guilt-specific activity was also observed in the paracingulate dorsomedial prefrontal cortex, a critical "Theory of Mind" region, which overlapped with brain areas of self-referential processing identified in an independent task. These results provide new insights on the unique nature of guilt as a "self-conscious" moral emotion and the neural bases of antisocial disorders characterized by impaired guilt processing.

Socially induced false memories in the absence of misinformation.

Ample evidence shows that post-encoding misinformation from others can induce false memories. Here, we demonstrate in two experiments a new, tacit form of socially generated false memories, resulting from interpersonal co-monitoring at encoding without communication of misinformation. Pairs of participants jointly viewed semantically coherent word lists, presented successively in blue, green, or red letters. Each individual was instructed to memorize words presented in one of the colors. One color remained unassigned (control condition). Participants (total N = 113) reported more false memories for non-presented words (lures) semantically related to partner-assigned than to control lists, although both list types were equally irrelevant to their own task. Notably, this effect also persisted for particularly rich memories. These findings show for the first time that social induction of false memories, even subjectively rich ones, does not necessarily require communication of deceptive information. This has important implications both theoretically and practically (e.g., in forensic contexts).

Elevated cortisol at retrieval suppresses false memories in parallel with correct memories.

Retrieving a memory is a reconstructive process in which encoded representations can be changed and distorted. This process sometimes leads to the generation of "false memories," that is, when people remember events that, in fact, never happened. Such false memories typically represent a kind of "gist" being extracted from single encountered events. The stress hormone cortisol is known to substantially impair memory retrieval. Here, in a double-blind, placebo-controlled crossover design, we tested the effect of an intravenous cortisol infusion before retrieval testing on the occurrence of false memories and on recall of correct memories using a modified Deese-Roediger-McDermott paradigm. Subjects studied sets of abstract shapes, with each set being derived from one prototype that was not presented during learning. At retrieval taking place 9 hr after learning, subjects were presented with studied shapes, nonstudied shapes, and the prototypes, and had to indicate whether or not each shape had been presented at learning. Cortisol administration distinctly reduced susceptibility to false memories (i.e., false recognition of prototypes) and, in parallel, impaired retrieval of correct memories (i.e., correct recognition of studied shapes). Response bias as well as confidence ratings and remember/know/guess judgments were not affected. Our results support gist-based theories of false memory generation, assuming a simultaneous storage of the gist and specific details of an event. Cortisol, by a general impairing influence on retrieval operations, decreases, in parallel, retrieval of false (i.e., gist) and correct (i.e., specific) memories for the event.

Opposite effects of cortisol on consolidation of temporal sequence memory during waking and sleep.

Memory functions involve three stages: encoding, consolidation, and retrieval. Modulating effects of glucocorticoids (GCs) have been consistently observed for declarative memory with GCs enhancing encoding and impairing retrieval, but surprisingly, little is known on how GCs affect memory consolidation. Studies in rats suggest a beneficial effect of GCs that were administered during postlearning wake periods, whereas in humans, cortisol impaired memory consolidation when administered during postlearning sleep. These inconsistent results raise the question whether effects of GCs critically depend on the brain state during consolidation (sleep vs. wake). Here, we compare for the first time directly the effects of cortisol on memory consolidation during postlearning sleep and wakefulness in different measures of declarative memory. Cortisol (13 mg vs. placebo) was intravenously infused during a postlearning nap or a time-matched period of wakefulness after participants had encoded neutral and emotional text material. Memory for the texts was tested (a) by asking for the contents of the texts ("item" memory) and (b) for the temporal order of the contents within the texts ("relational" memory). Neither postlearning infusion of cortisol during sleep nor during wakefulness affected retention of content words of emotional or neutral texts. Critically, however, the retention of temporal order within the texts, known to rely most specifically on the hippocampus proper within the medial-temporal lobe memory system, was distinctly improved by cortisol infusion during the wake phase but impaired by cortisol during sleep. These results point toward fundamentally different mechanisms of hippocampal memory consolidation, depending on the brain state.

Neural precursors of delayed insight.

The solution of a problem left unresolved in the evening can sometimes pop into mind as a sudden insight after a night of sleep in the following morning. Although favorable effects of sleep on insightful behavior have been experimentally confirmed, the neural mechanisms determining this delayed insight remain unknown. Here, using fMRI, we characterize the neural precursors of delayed insight in the number reduction task (NRT), in which a hidden task structure can be learned implicitly, but can also be recognized explicitly in an insightful process, allowing immediate qualitative improvement in task performance. Normal volunteers practiced the NRT during two fMRI sessions (training and retest), taking place 12 hours apart after a night of sleep. After this delay, half of the subjects gained insight into the hidden task structure ("solvers," S), whereas the other half did not ("nonsolvers," NS). Already at training, solvers and nonsolvers differed in their cerebral responses associated with implicit learning. In future solvers, responses were observed in the superior frontal sulcus, posterior parietal cortex, and the insula, three areas mediating controlled processes and supporting early learning and novice performance. In contrast, implicit learning was related to significant responses in the hippocampus in nonsolvers. Moreover, the hippocampus was functionally coupled with the basal ganglia in nonsolvers and with the superior frontal sulcus in solvers, thus potentially biasing participants' strategy towards implicit or controlled processes of memory encoding, respectively. Furthermore, in solvers but not in nonsolvers, response patterns were further transformed overnight, with enhanced responses in ventral medial prefrontal cortex, an area previously implicated in the consolidation of declarative memory. During retest in solvers, before they gain insight into the hidden rule, significant responses were observed in the same medial prefrontal area. After insight, a distributed set of parietal and frontal areas is recruited among which information concerning the hidden rule can be shared in a so-called global workspace.

Sleep inspires insight.

Insight denotes a mental restructuring that leads to a sudden gain of explicit knowledge allowing qualitatively changed behaviour. Anecdotal reports on scientific discovery suggest that pivotal insights can be gained through sleep. Sleep consolidates recent memories and, concomitantly, could allow insight by changing their representational structure. Here we show a facilitating role of sleep in a process of insight. Subjects performed a cognitive task requiring the learning of stimulus-response sequences, in which they improved gradually by increasing response speed across task blocks. However, they could also improve abruptly after gaining insight into a hidden abstract rule underlying all sequences. Initial training establishing a task representation was followed by 8 h of nocturnal sleep, nocturnal wakefulness, or daytime wakefulness. At subsequent retesting, more than twice as many subjects gained insight into the hidden rule after sleep as after wakefulness, regardless of time of day. Sleep did not enhance insight in the absence of initial training. A characteristic antecedent of sleep-related insight was revealed in a slowing of reaction times across sleep. We conclude that sleep, by restructuring new memory representations, facilitates extraction of explicit knowledge and insightful behaviour.

Visual-procedural memory consolidation during sleep blocked by glutamatergic receptor antagonists.

Visual cortex plasticity is enhanced by sleep. It is hypothesized that a reactivation of glutamatergic synapses is essential for this form of plasticity to occur after learning. To test this hypothesis, human subjects practiced a visual texture discrimination skill known to require post-training sleep for improvements to occur. During sleep, glutamatergic transmission was inhibited by administration of the two glutamate antagonists, caroverine and ketamine, targeting the ionotropic NMDA and AMPA receptors. Both substances given during consolidation sleep in a placebo controlled crossover design were able to prevent improvement of the skill measured the next morning. An off-line activation of glutamatergic synapses therefore seems to play a critical part in the consolidation of plastic changes in the visual cortex.

Shifting from implicit to explicit knowledge: different roles of early- and late-night sleep.

Sleep has been shown to promote the generation of explicit knowledge as indicated by the gain of insight into previously unrecognized task regularities. Here, we explored whether this generation of explicit knowledge depends on pre-sleep implicit knowledge, and specified the differential roles of slow-wave sleep (SWS) vs. rapid eye movement (REM) sleep in this process. Implicit and explicit knowledge (insight) related to a hidden regularity were assessed in an associative motor-learning task (number reduction task, NRT), which was performed in two sessions (initial practice and retest) separated by 3 h of either early-night sleep, rich in SWS, or of late-night sleep, rich in REM sleep. About half of the participants developed signs of implicit rule knowledge (i.e., speeded reaction times for responses determined by the hidden regularity) at initial practice preceding early or late sleep. Of these, half developed explicit knowledge across early-night sleep, significantly more than across late-night sleep. In contrast, late-night subjects preferentially remained on the level of implicit rule knowledge after sleep. Participants who did not develop implicit knowledge before sleep had comparable rates of transition to implicit or explicit knowledge across early and late sleep. If subjects gained explicit knowledge across sleep, this was associated with lower amounts of REM sleep, specifically in the late-night group. SWS predominant during the early night may restructure implicit memory representations in a way that allows creating an explicit representation afterward, whereas REM sleep in the late night appears to stabilize them in their implicit form.

Changes in processing of masked stimuli across early- and late-night sleep: a study on behavior and brain potentials.

Sleep has proven to support the memory consolidation in many tasks including learning of perceptual skills. Explicit, conscious types of memory have been demonstrated to benefit particularly from slow-wave sleep (SWS), implicit, non-conscious types particularly from rapid eye movement (REM) sleep. By comparing the effects of early-night sleep, rich in SWS, and late-night sleep, rich in REM sleep, we aimed to separate the contribution of these two sleep stages in a metacontrast masking paradigm in which explicit and implicit aspects in perceptual learning could be assessed separately by stimulus identification and priming, respectively. We assumed that early sleep intervening between two sessions of task performance would specifically support stimulus identification, while late sleep would specifically support priming. Apart from overt behavior, event-related EEG potentials (ERPs) were measured to record the cortical mechanisms associated with behavioral changes across sleep. In contrast to our hypothesis, late-night sleep appeared to be more important for changes of behavior, both for stimulus identification, which tended to improve across late-night sleep, and for priming, with the increase of errors induced by masked stimuli correlating with the duration of REM sleep. ERP components proved sensitive to presence of target shapes in the masked stimuli and to their priming effects. Of these components, the N2 component, indicating processing of conflict, became larger across early-night sleep and was related to the duration of S4 sleep, the deepest substage of SWS containing particularly high portions of EEG slow waves. These findings suggest that sleep promotes perceptual learning primarily by its REM sleep portion, but indirectly also by way of improved action monitoring supported by deep slow-wave sleep.

When Does Oxytocin Affect Human Memory Encoding? The Role of Social Context and Individual Attachment Style.

The neuropeptide oxytocin plays an essential role in regulating social behavior and has been implicated in a variety of human cognitive processes in the social domain, including memory processes. The present study investigates the influence of oxytocin on human memory encoding, taking into account social context and personality, which have previously been neglected as moderators for how oxytocin affects memory encoding. To examine the role of social context of encoding, we employed an established experimental paradigm in which participants perform a word-categorization task in either a joint (social) or individual (non-social) setting. To investigate the role of socially relevant personality factors, participants' adult attachment style (AAS) was assessed. Previous research has identified attachment style as a potent moderator of oxytocin effects in the social-cognitive domain, but here we investigated for the first time its role in memory encoding. Participants were invited in pairs and received either placebo or oxytocin intranasally. Forty-five minutes later, they were instructed to react to different word categories within a list of successively presented words. This task was performed individually in the non-social condition and simultaneously with the partner in the social condition. After a 24-h delay, memory for all words was tested individually in a surprise recognition memory test. Oxytocin effects on memory accuracy depended on participants' AAS. Specifically, oxytocin positively affected memory for participants who scored low on attachment dependence (who find dependence on others uncomfortable), but negatively affected memory for high scorers (who are comfortable depending on others). Oxytocin effects were not moderated by social vs. non-social context at encoding, and we discuss reasons for this outcome. Regardless of encoding condition or personality, oxytocin led to more liberal responding in the recognition memory test, which was also reflected in significantly higher false alarm rates (FARs) and a trend towards higher hit rates (HRs) compared to placebo. Overall, our results are consistent with an interactionist view on oxytocin effects on human cognitive functioning. Future research should further examine how oxytocin affects response biases via previous encoding and the ways in which biological dispositions linked to attachment style affect the process of memory encoding.

The Joint Action Effect on Memory as a Social Phenomenon: The Role of Cued Attention and Psychological Distance.

In contrast to individual tasks, a specific social setting is created when two partners work together on a task. How does such a social setting affect memory for task-related information? We addressed this issue in a distributed joint-action paradigm, where two team partners respond to different types of information within the same task. Previous work has shown that joint action in such a task enhances memory for items that are relevant to the partner's task but not to the own task. By removing critical, non-social confounds, we wanted to pinpoint the social nature of this selective memory advantage. Specifically, we created joint task conditions in which participants were aware of the shared nature of the concurrent task but could not perceive sensory cues to the other's responses. For a differentiated analysis of the social parameters, we also varied the distance between partners. We found that the joint action effect emerged even without sensory cues from the partner, and it declined with increasing distance between partners. These results support the notion that the joint-action effect on memory is in its core driven by the experience of social co-presence, and does not simply emerge as a by-product of partner-generated sensory cues.

Brief sleep after learning keeps emotional memories alive for years.

BACKGROUND: Sleep after learning supports memory consolidation. However, long-lasting memory effects of sleep have not yet been investigated. Postlearning sleep may be particularly involved in the long-term retention of emotional memories and could thereby contribute to the development of posttraumatic stress disorder (PTSD), a disease thought to result from overconsolidation of traumatic memories. METHODS: Subjects (healthy men) who had learned neutral and emotional texts immediately before sleeping or remaining awake for the subsequent 3 hours were recontacted after 4 years for long-term memory assessment (forced-choice recognition test). RESULTS: Sleep following learning compared with wakefulness enhanced memory for emotional texts after 4 years (p = .001). No such enhancement was observed for neutral texts (p = .571). CONCLUSIONS: Brief periods of sleep immediately following learning cause preservation of emotional memories over several years. Sleep deprivation in the immediate aftermath of traumatic events could be a promising therapeutic measure to prevent PTSD.

Effects of cortisol suppression on sleep-associated consolidation of neutral and emotional memory.

BACKGROUND: Previous research indicates that hippocampus-dependent declarative memory benefits from early nocturnal sleep, when slow-wave sleep (SWS) prevails and cortisol release is minimal, whereas amygdala-dependent emotional memory is enhanced through late sleep, when rapid eye movement (REM) sleep predominates. The role of the strong cortisol rise accompanying late sleep for emotional memory consolidation has not yet been investigated. METHODS: Effects of the cortisol synthesis inhibitor metyrapone on sleep-associated consolidation of memory for neutral and emotional texts were investigated in a randomized, double-blind, placebo-controlled study in 14 healthy men. Learning took place immediately before treatment, which was followed by 8 hours of sleep. Retrieval was tested at 11 am the next morning. RESULTS: Metyrapone suppressed cortisol during sleep and blocked particularly the late-night rise in cortisol. It reduced SWS and concomitantly impaired the consolidation of neutral texts. Emotional texts were spared from this impairing influence, however. Metyrapone even amplified emotional enhancement in text recall indicating amygdala-dependent memory. CONCLUSIONS: Cortisol blockade during sleep impairs hippocampus-dependent declarative memory formation but enhances amygdala-dependent emotional memory formation. The natural cortisol rise during late sleep may thus protect from overshooting emotional memory formation, a mechanism possibly pertinent to the development of posttraumatic stress disorder.