Remembering specific features of emotional events across time: The role of REM sleep and prefrontal theta oscillations.

When an episode of emotional significance is encountered, it often results in the formation of a highly resistant memory representation that is easily retrieved for many succeeding years. Recent research shows that beyond generic consolidation processes, rapid eye movement (REM) sleep importantly contributes to this effect. However, the boundary conditions of consolidation processes during REM sleep, specifically whether these extend to source memory, have not been examined extensively. The current study tested the effects of putative consolidation processes emerging during REM sleep and slow wave sleep (SWS) on item and source memory of negative and neutral images, respectively. Results demonstrate superior emotional relative to neutral item memory retention after both late night REM sleep and early night SWS. Emotional source memory, on the other hand, exhibited an attenuated decline following late night REM sleep, whereas neutral source memory was selectively preserved across early night SWS. This pattern of results suggests a selective preservation of emotional source memory during REM sleep that is functionally dissociable from SWS-dependent reprocessing of neutral source memory. This was further substantiated by a neurophysiological dissociation: Postsleep emotional source memory was selectively correlated with frontal theta lateralization (REM sleep), whereas postsleep neutral item memory was correlated with SWS spindle power. As such, the present results contribute to a more comprehensive characterization of sleep-related consolidation mechanisms underlying emotional and neutral memory retention. Subsidiary analysis of emotional reactivity to previously encoded material revealed an enhancing rather than attenuating effect of late night REM sleep on emotional responses.

Flexibility predicts chronic anxiety and depression during the first year of the COVID-19 pandemic-A longitudinal investigation of mental health trajectories.

OBJECTIVE: The COVID-19 pandemic is a significant stressor, potentially putting the well-being of the general population at risk. However, a significant proportion of the population exhibits resilience, raising questions regarding psychological constructs that could contribute to resilient coping. Studies indicate that flexibility, defined as the ability to adapt to changing contextual demands by employing various emotional, cognitive, and behavioral strategies, may significantly contribute to coping with long-term stressors such as COVID-19. METHOD: Cognitive and coping flexibility domains and longitudinal trajectories of anxiety and depression were assessed at three-time points across 13 months in 571 Israelis. RESULTS: Analyses revealed four different trajectories for anxiety: resilient (66%), chronic (22%), emerging (7%), and improving (6%), and two trajectories for depression: resilient (87%) and chronic (13%). Individuals in the chronic trajectory group (for both anxiety and depression) exhibited lower cognitive flexibility and coping flexibility levels than individuals in the resilient trajectory group. Across time, anxiety and depression were linked to clinically significant posttraumatic stress disorder-like symptoms. CONCLUSIONS: Low cognitive and coping flexibility are linked to the probability of experiencing chronic mental health problems, making them a potential target for prevention and treatment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effects of early morning nap sleep on associative memory for neutral and emotional stimuli.

Emotional events are preferentially retained in episodic memory. This effect is commonly attributed to enhanced consolidation and has been linked specifically to rapid eye movement (REM) sleep physiology. While several studies have demonstrated an enhancing effect of REM sleep on emotional item memory, it has not been thoroughly explored whether this effect extends to the retention of associative memory. Moreover, it is unclear how non-rapid eye movement (NREM) sleep contributes to these effects. The present study thus examined associative recognition of emotional and non-emotional material across an early morning nap (N = 23) and sustained wakefulness (N = 23). Nap group subjects demonstrated enhanced post-sleep associative memory performance, which was evident across both valence categories. Subsequent analyses revealed significant correlations between NREM spindle density and pre-sleep memory performance. Moreover, NREM spindle density was positively correlated with post-sleep neutral associative memory performance but not with post-sleep emotional associative memory. Accordingly, only neutral associative memory, but not emotional associative memory, was significantly correlated with spindle density after an additional night of sleep (+24 h). These results illustrate a temporally persistent relationship between spindle density and memory for neutral associations, whereas post-sleep emotional associative memory appears to be disengaged from NREM-sleep-dependent processes.