scholarly journals Slow oscillation-spindle coupling impairs emotional memory consolidation following stress

2020 ◽  
Author(s):  
Dan Denis ◽  
Sara Y. Kim ◽  
Sarah M. Kark ◽  
Ryan T. Daley ◽  
Elizabeth A. Kensinger ◽  
...  

AbstractSleep and stress have both been shown to enhance emotional memory consolidation. They also interact, with the largest benefit of sleep on emotional memory being seen when stress occurs either shortly before or after memory encoding. Slow wave sleep (SWS) is believed to be critical for episodic memory consolidation, facilitated by the coupling of slow oscillations and sleep spindles. However, prior work in humans has only demonstrated slow oscillation-spindle coupling to be associated with consolidation of neutral information in non-stressed participants. Whether coupling interacts with stress to facilitate emotional memory consolidation is unknown. To address this exploratory question, we reanalyzed an existing dataset of N=64 individuals. Participants underwent a psychosocial stressor (n=32) or comparable control (n=32) prior to the encoding of 150 line drawings of neutral, positive, and negative images. All participants then slept overnight with polysomnographic recordings. The next day, they were given a surprise memory test. In the stress group, percentage of time spent in SWS was positively correlated with memory for images of all valences (all r>.35, p<.043). Results were primarily driven by those who showed a high cortisol response to the stressor (all r>.65, p<.007), compared to low cortisol responders (all r<.31, all p>.25). However, the amount of slow oscillation-spindle coupling during SWS was negatively associated with neutral (r= −.45, p=.01) and emotional (r=−.66, p<.001) memory in the stress group. The negative association with emotional memory was significantly stronger than for neutral memory (Meng z=2.04, p=.04). Between stress and control groups, there were no differences in any of the sleep measures assessed. These results highlight the importance of considering sleep microarchitecture events in addition to overall sleep stage time and suggests that stress may alter the relationship between SWS and memory consolidation.

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A43-A43
Author(s):  
D Denis ◽  
S Y Kim ◽  
S M Kark ◽  
R T Daley ◽  
S E Alger ◽  
...  

Abstract Introduction Sleep and stress can both enhance emotional memory consolidation. During slow wave sleep (SWS), oscillatory features such as slow oscillations (SO), sleep spindles (SS), and critically, their coupling, are believed to facilitate consolidation. How they relate to emotional memory consolidation is less clear, and how stress interacts with these oscillations is unknown. Methods In this study, participants either underwent a psychosocial stressor (the Trier Social Stress Task; n = 32) or a control task (n=32). Next, they encoded 150 neutral, negative, and positive images while undergoing fMRI. Participants then spent the night in the lab with polysomnographic recording. The next day they were given a surprise recognition test. Results There was better memory for emotional compared to neutral items in the stress group. Within this group, % of time spent in SWS positively correlated with emotional memory consolidation (r=.37, p=.039). However, SO-SS coupling during SWS was negatively correlated with emotional memory consolidation in the stress group (r=-.47, p=.007). This was driven by participants who showed a high cortisol response following the stressor (cortisol * coupling interaction p=.03) Results were similar when negative and positive items were analyzed separately. No correlations with neutral item memory were found. Conclusion Sleep stage time and sleep oscillatory activity exert different effects on emotional memory following stress, and that SO-SS coupling does not always promote episodic memory consolidation. SO-SS coupling can impair emotional memories when encoded during periods of elevated stress, and accompanying neuromodulators such as cortisol are high. Support National Science Foundation, Grant/Award Number: BXS-1539361


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Isabel C. Hutchison ◽  
Stefania Pezzoli ◽  
Maria-Efstratia Tsimpanouli ◽  
Mahmoud E. A. Abdellahi ◽  
Penelope A. Lewis

AbstractA growing body of evidence suggests that sleep can help to decouple the memory of emotional experiences from their associated affective charge. This process is thought to rely on the spontaneous reactivation of emotional memories during sleep, though it is still unclear which sleep stage is optimal for such reactivation. We examined this question by explicitly manipulating memory reactivation in both rapid-eye movement sleep (REM) and slow-wave sleep (SWS) using targeted memory reactivation (TMR) and testing the impact of this manipulation on habituation of subjective arousal responses across a night. Our results show that TMR during REM, but not SWS significantly decreased subjective arousal, and this effect is driven by the more negative stimuli. These results support one aspect of the sleep to forget, sleep to remember (SFSR) hypothesis which proposes that emotional memory reactivation during REM sleep underlies sleep-dependent habituation.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A16-A16
Author(s):  
Megan Collins ◽  
Erin Wamsley ◽  
Hailey Napier ◽  
Madeline Ray

Abstract Introduction Slow wave sleep (SWS) is thought to especially benefit declarative memory (i.e., memory for facts and events). As such, recent studies have used various methods to experimentally increase the amount of slow wave sleep that participants obtain, with the goal of assessing how SWS affects declarative memory consolidation. Studies dating back decades have reported that exercising before sleep may increase time spent in SWS. Thus, the aim of the current project was to determine whether exercising after learning verbal information enhances slow wave sleep during a subsequent nap and/or enhances memory for verbal information. Methods Participants who exercised regularly were recruited to attend two 2.5hr laboratory sessions. During each session, they trained on a paired associates learning task and then completed either a 20min cardiovascular exercise routine or a 20min stretching routine. Following a 1hr nap opportunity, participants were tested on their memory. PSG was recorded during the nap, and scored following AASM criteria. Participants were excluded from analysis if they failed to sleep for at least 10 min. Following exclusions, n=30 participants were included in analysis. Results Contrary to our hypotheses, there was no significant difference between the exercise and stretching conditions for minutes spent in slow wave sleep (p=.16), % time spent in slow wave sleep (p=.22), or raw improvement in paired associated performance (p=.23). The amount of SWS obtained during the nap did not correlate with performance in either condition (SWS min vs. memory in exercise condition: r28=.10, p=.60; sleep condition: r28=-.06, p=.74). Exercise did not affect time spent in any other sleep stage, nor did it affect total sleep time. Conclusion Contrary to our hypotheses and the results of prior research, we were unable to detect a significant effect of exercise on slow wave sleep. Also contrary to our hypotheses, exercise did not affect memory retention across the nap interval. These null results could indicate that there is no effect of exercise on nap sleep and/or associated memory retention. However, it could also be that we lacked sufficient power to detect effects that were smaller than expected. Support (if any):


2020 ◽  
Vol 31 (1) ◽  
pp. 324-340
Author(s):  
Pavel Sanda ◽  
Paola Malerba ◽  
Xi Jiang ◽  
Giri P Krishnan ◽  
Jorge Gonzalez-Martinez ◽  
...  

Abstract The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo–cortico–thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.


2019 ◽  
Author(s):  
Sarah K. Schäfer ◽  
Benedikt E. Wirth ◽  
Marlene Staginnus ◽  
Nicolas Becker ◽  
Tanja Michael ◽  
...  

SummaryNumerous studies have shown that sleep enhances the consolidation of episodic memory. However, it remains unclear whether this consolidation benefit is moderated by the emotional valence of the learned material. To clarify whether sleep selectively enhances the consolidation of emotional material, we conducted a meta-analysis including N = 1,059 observations. Overall, our results do not support this hypothesis. When only studies with a sleep-group wake-group comparison were included in the analysis (k = 22), the retention advantage for emotional over neutral material was not significantly different between sleep and wake groups. When studies initially lacking a wake-control group were included in the analysis after statistical estimation of wake-group parameters, the retention advantage for emotional material was significantly larger in wake-groups than in sleep-groups (k = 34). Interestingly, however, an additional analysis of k = 8 studies investigating the selective effects of rapid-eye-movement sleep and slow-wave sleep on emotional memory consolidation provided evidence for a selective enhancement of emotional over neutral memory consolidation after rapid-eye-movement sleep compared to slow-wave sleep. These results suggest that sleep does not generally enhance emotional memory consolidation over neutral memory consolidation. However, specific sleep stages might preferentially enhance consolidation of emotional and neutral material, respectively.


SLEEP ◽  
2014 ◽  
Vol 37 (4) ◽  
pp. 701-707 ◽  
Author(s):  
Scott A. Cairney ◽  
Simon J. Durrant ◽  
Johan Hulleman ◽  
Penelope A. Lewis

1993 ◽  
Vol 30 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Andrew Mccance ◽  
David Roberts-Harry ◽  
Martyn Sherriff ◽  
Michael Mars ◽  
William J.B. Houston

The study models of a group of adult Sri Lankan patients with clefts of the secondary palate were investigated. Tooth-size and arch-dimension comparisons were made with a comparable control group. Significant differences were found between the cleft and control groups in tooth sizes, chord lengths, and arch widths. The cleft group dimensions were generally smaller than those of the control group. Overjets were larger in the cleft group.


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