Sleep’s impact on emotional memory: A meta-analysis of whole-night, nap, and REM sleep effects

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.

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Complementary Roles of Slow-Wave Sleep and Rapid Eye Movement Sleep in Emotional Memory Consolidation

Cerebral Cortex ◽

10.1093/cercor/bht349 ◽

2014 ◽

Vol 25 (6) ◽

pp. 1565-1575 ◽

Cited By ~ 59

Author(s):

S. A. Cairney ◽

S. J. Durrant ◽

R. Power ◽

P. A. Lewis

Keyword(s):

Eye Movement ◽

Slow Wave ◽

Memory Consolidation ◽

Slow Wave Sleep ◽

Emotional Memory ◽

Rapid Eye Movement ◽

Rapid Eye Movement Sleep

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Effects of sleep-promoting factor from human urine on sleep cycle of cats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1981.241.4.e269 ◽

1981 ◽

Vol 241 (4) ◽

pp. E269-E274

Author(s):

J. E. Garcia-Arraras

Keyword(s):

Cerebrospinal Fluid ◽

Eye Movement ◽

Slow Wave ◽

Human Urine ◽

Slow Wave Sleep ◽

Sleep Cycle ◽

Rapid Eye Movement ◽

Rapid Eye Movement Sleep ◽

Artificial Cerebrospinal Fluid ◽

Normal Sleep

Slow-wave sleep (SWS) and rapid-eye-movement sleep (REM) were recorded in cats for 32 h a) under control conditions, b) following intraventricular infusions of artificial cerebrospinal fluid (CSF), and c) following infusions of sleep-promoting factor S prepared from human urine (SPU). During the first 12 h after receiving artificial CSF, the cats slept 4.9 +/- 0.2 h in slow-wave sleep (SWS) and 1.4 +/- 0.1 h in REM. Similar values were obtained from the same cats under control conditions. After infusions of SPU, the duration of SWS in the same cats increased to an average of 6.9 +/- 0.5 h with no significant change in REM averaged over 12 h; a transient decrease of REM in the first 4 h was fully compensated in subsequent hours. The increased SWS induced by the sleep-promoting factor from human urine subsided after 12 h, and there was no compensatory increase in wakefulness during the subsequent 20 h. The normal sleep cycle was not affected. In cats, therefore, the primary effect of SPU is to increase normal SWS, with little effect on REM.

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Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects

Journal of Applied Physiology ◽

10.1152/japplphysiol.00658.2002 ◽

2003 ◽

Vol 94 (3) ◽

pp. 883-890 ◽

Cited By ~ 44

Author(s):

Michael F. Fitzpatrick ◽

Helen S. Driver ◽

Neela Chatha ◽

Nha Voduc ◽

Alison M. Girard

Keyword(s):

Eye Movement ◽

Slow Wave ◽

Sleep Stage ◽

Minute Ventilation ◽

Normal Subjects ◽

Sleep Stages ◽

Rapid Eye Movement ◽

Nasal Mask ◽

Rapid Eye Movement Sleep ◽

Significant Difference

The oral and nasal contributions to inhaled ventilation were simultaneously quantified during sleep in 10 healthy subjects (5 men, 5 women) aged 43 ± 5 yr, with normal nasal resistance (mean 2.0 ± 0.3 cmH2O · l−1 · s−1) by use of a divided oral and nasal mask. Minute ventilation awake (5.9 ± 0.3 l/min) was higher than that during sleep (5.2 ± 0.3 l/min; P < 0.0001), but there was no significant difference in minute ventilation between different sleep stages ( P = 0.44): stage 2 5.3 ± 0.3, slow-wave 5.2 ± 0.2, and rapid-eye-movement sleep 5.2 ± 0.2 l/min. The oral fraction of inhaled ventilation during wakefulness (7.6 ± 4%) was not significantly different from that during sleep (4.3 ± 2%; mean difference 3.3%, 95% confidence interval −2.1–8.8%, P = 0.19), and no significant difference ( P = 0.14) in oral fraction was observed between different sleep stages: stage two 5.1 ± 2.8, slow-wave 4.2 ± 1.8, rapid-eye-movement 3.1 ± 1.7%. Thus the inhaled oral fraction in normal subjects is small and does not change significantly with sleep stage.

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The dream-lag effect: Selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep

Neurobiology of Learning and Memory ◽

10.1016/j.nlm.2015.01.009 ◽

2015 ◽

Vol 122 ◽

pp. 98-109 ◽

Cited By ~ 36

Author(s):

E. van Rijn ◽

J.-B. Eichenlaub ◽

P.A. Lewis ◽

M.P. Walker ◽

M.G. Gaskell ◽

...

Keyword(s):

Eye Movement ◽

Slow Wave ◽

Slow Wave Sleep ◽

Rapid Eye Movement ◽

Rapid Eye Movement Sleep ◽

Significant Events ◽

Lag Effect ◽

Selective Processing

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Remifentanil Inhibits Rapid Eye Movement Sleep but Not the Nocturnal Melatonin Surge in Humans

Anesthesiology ◽

10.1097/aln.0b013e3181684bc3 ◽

2008 ◽

Vol 108 (4) ◽

pp. 627-633 ◽

Cited By ~ 23

Author(s):

Christopher P. Bonafide ◽

Natalie Aucutt-Walter ◽

Nicole Divittore ◽

Tonya King ◽

Edward O. Bixler ◽

...

Keyword(s):

Plasma Concentration ◽

Sleep Disturbance ◽

Eye Movement ◽

Repeated Measures ◽

Slow Wave Sleep ◽

Constant Infusion ◽

Sleep Stages ◽

Rapid Eye Movement ◽

Rapid Eye Movement Sleep ◽

Placebo Capsule

Background Postoperative patients are sleep deprived. Opioids, commonly administered for postoperative pain control, are often mistakenly considered inducers of naturally occurring sleep. This study describes the effect of the opioid remifentanil on nocturnal sleep in healthy volunteers. In addition, this study tests the hypothesis that opioid-induced sleep disturbance is caused by a circadian pacemaker disturbance, reflected by suppressed nocturnal plasma concentration of melatonin. Methods Polysomnography was performed in 10 volunteers from 11:00 pm to 7:00 am for four nights at 6-day intervals. On two nights, remifentanil (0.01-0.04 microg x kg x min) was infused from 10:30 pm to 7:00 am, and either a placebo capsule or 3.0 mg melatonin was administered at 10:30 pm. On two additional nights, saline was infused, and the placebo or melatonin capsules were administered at 10:30 pm. Blood was drawn at 12:00 am, 3:00 am, and 6:00 am to measure the plasma concentration of melatonin and cortisol. A repeated-measures analysis of variance model was used to determine the effect of remifentanil on sleep stages, the effect of remifentanil on the plasma concentration of melatonin, and the effect of exogenous melatonin on remifentanil-induced sleep disturbance. Results Remifentanil inhibited rapid eye movement sleep (14.1 +/- 7.2% to 3.9 +/- 6.9%). The amount of slow wave sleep decreased from 6.8 +/- 7.6% to 3.2 +/- 6.1%, but this decrease was not statistically significant. Remifentanil did not decrease melatonin concentration. Melatonin administration did not prevent remifentanil-induced sleep disturbance. Conclusions An overnight constant infusion of remifentanil inhibits rapid eye movement sleep without suppressing the nocturnal melatonin surge.

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