Sleep-Induced Changes in Associative Memory

1999 ◽  
Vol 11 (2) ◽  
pp. 182-193 ◽  
Author(s):  
Robert Stickgold ◽  
Laurie Scott ◽  
Cynthia Rittenhouse ◽  
J. Allan Hobson
Keyword(s):  
Semantic Priming ◽  
Associative Memory ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Memory Systems ◽  
Cognitive Testing ◽  
Sleep Cycle ◽  
Sleep State ◽  
Before And After ◽  
Carry Over

The notion that dreaming might alter the strength of associative links in memory was first proposed almost 200 years ago. But no strong evidence of such altered associative links has been obtained. Semantic priming can be used to quantify the strength of associative links between pairs of words; it is thought to measure the automatic spread of activation from a “node” representing one word to nodes representing semantically related words. Semantic priming could thus be used to test for global alterations in the strengths of associative links across the wake-sleep cycle. Awakenings from REM and nonREM (NREM) sleep produce a period of state carry-over during which performance is altered as a result of the brain's slow transition to full wakefulness, and cognitive testing in this period can provide information about the functioning of the brain during the prior sleep period. When subjects were tested across the night—before and after a night's sleep as well as immediately following forced awakenings from REM and NREM sleep—weak priming (e.g., thief-wrong) was found to be state dependent (p = 0.016), whereas strong priming (e.g., hot-cold) was not (p = 0.89). Weak primes were most effective in the presleep and REM sleep conditions and least effective in NREM and postsleep conditions. Most striking are analyses comparing weak and strong priming within each wake-sleep state. Contrary to the normal pattern of priming, subjects awakened from REM sleep showed greater priming by weak primes than by strong primes (p = 0.01). This result was seen in each of three protocols. In contrast, strong priming exceeded weak priming in NREM sleep. The shift in weak priming seen after REM sleep awakenings suggests that cognition during REM sleep is qualitatively different from that of waking and NREM sleep and may reflect a shift in associative memory systems, a shift that we hypothesize underlies the bizarre and hyperassociative character of REM-sleep dreaming. Known changes in brainstem activity that control the transition into and maintenance of REM sleep provide a possible explanation of this shift.

scholarly journals Toward asleep DBS: cortico-basal ganglia spectral and coherence activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Rem Sleep ◽  
Standard Procedure ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Advanced Parkinson’S Disease ◽  
Low Frequency Power ◽  
The Brain ◽  
Frequency Power

AbstractDeep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.

Correlations using the NREM-REM sleep cycle frequency support distinct regulation mechanisms for REM and NREM sleep

2002 ◽  
Vol 93 (1) ◽  
pp. 141-146 ◽  
Author(s):  
O. Le Bon ◽  
L. Staner ◽  
S. K. Rivelli ◽  
G. Hoffmann ◽  
I. Pelc ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Healthy Subjects ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Cycle Frequency ◽  
Regulation Mechanisms ◽  
The Mean ◽  
Number Of Cycles ◽  
The Relationship ◽  
Sleep Cycles

Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/NREM sleep ratio and the mean number of NREM-REM sleep cycles across 3 consecutive nights. The rationale was that, if REM and NREM sleep are tightly associated, their ratio should be comparable whatever the cycle frequency in the night. Twenty-six healthy subjects of both sexes were recorded at their home for 4 consecutive nights. The correlation between the REM/NREM sleep ratio and the number of cycles was highly significant. Of the two sleep components, REM sleep was associated to the number of cycles, whereas NREM sleep was not. This suggests that the relationship between REM sleep and NREM sleep is rather weak within cycles, does not support the concept of NREM-REM sleep cycles as miniature units of the sleep process, and favors the concept of distinct mechanisms of regulation for the two components.

Prolongation of the laryngeal chemoreflex after inhibition of the rostral ventral medulla in piglets: a role in SIDS?

2003 ◽  
Vol 94 (5) ◽  
pp. 1883-1895 ◽  
Author(s):  
Liesbeth van der Velde ◽  
Aidan K. Curran ◽  
James J. Filiano ◽  
Robert A. Darnall ◽  
Donald Bartlett ◽  
...  
Keyword(s):  
Eye Movement ◽  
Sudden Infant Death Syndrome ◽  
Rem Sleep ◽  
Infant Death ◽  
Nrem Sleep ◽  
Sudden Infant Death ◽  
Sudden Infant ◽  
Rapid Eye Movement ◽  
Ventral Medulla ◽  
Before And After

We tested the hypothesis that inhibition of neurons within the rostral ventral medulla (RVM) would prolong the laryngeal chemoreflex (LCR), a putative stimulus in the sudden infant death syndrome (SIDS). We studied the LCR in 19 piglets, age 3–16 days, by injecting 0.05 ml of saline or water into the larynx during wakefulness, non-rapid eye movement (NREM) sleep, and REM sleep, before and after 1 or 10 mM muscimol dialysis in the RVM. Muscimol prolonged the LCR ( P < 0.05), and the prolongation was greater when the LCR was stimulated with water compared with saline ( P < 0.02). The LCR was longer during NREM sleep than during wakefulness and longest during REM sleep (REM compared with wakefulness). Muscimol had no effect on the likelihood of arousal from sleep after LCR stimulation. We conclude that the RVM provides a tonic facilitatory drive to ventilation that limits the duration of the LCR, and loss of this drive may contribute to the SIDS when combined with stimuli that inhibit respiration.

Circadian rhythms of sleep and wakefulness in mice: analysis using long-term automated recording of sleep

1985 ◽  
Vol 248 (3) ◽  
pp. R320-R330 ◽  
Author(s):  
G. S. Richardson ◽  
M. C. Moore-Ede ◽  
C. A. Czeisler ◽  
W. C. Dement
Keyword(s):  
Circadian Rhythms ◽  
Rem Sleep ◽  
Wheel Running ◽  
Nrem Sleep ◽  
Sleep State ◽  
Continuous Darkness ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Significant Difference ◽  
Wake State

Circadian rhythms of wheel-running activity and polygraphically defined wakefulness, rapid-eye-movement (REM) sleep and non-REM (NREM) sleep were continuously observed in ten mice (Mus musculus) under both alternating light-dark (LD 12:12) and continuous darkness (DD) conditions. Sleep-wake state was determined automatically using a computer-based method that allowed continuous recordings of from 60 to 280 days in duration. The sleep-wake state percentages (of the circadian cycle) thus obtained were in substantial agreement with other estimates for this or similar strains and showed no significant difference between LD 12:12 (wake 54.3%, NREM sleep 38.1%, REM sleep 7.6%) and DD (wake 53.1%, NREM sleep 39.9%, REM sleep 7.0%) conditions. All 10 mice exhibited clear circadian rhythms in each of the three states and wheel-running activity under both lighting conditions for the entire duration of observation. Probability functions, computed using stationary sections of data from all 10 mice, showed distinct waveforms for all three states and wheel running. These waveforms were remarkably similar under entrained and free-running conditions. This documentation of sustained circadian rhythmicity in sleep-wake state throughout observations of unprecedented length contradicts the currently common assertion that circadian control of sleep state is weaker than that of activity.

Medical-Psychological Implications of Recent Sleep Research

1970 ◽  
Vol 1 (4) ◽  
pp. 261-276 ◽  
Author(s):  
Chester A. Pearlman ◽  
Ramon Greenberg
Keyword(s):  
Rem Sleep ◽  
Emotional Adjustment ◽  
Psychological Adaptation ◽  
Nrem Sleep ◽  
Careful Consideration ◽  
Sleep Cycle ◽  
Sleep Research ◽  
Emotional Life ◽  
Neurophysiological Mechanisms ◽  
Hypnotic Drugs

Recent sleep research has shown that the conventional concept of sleep as a period of inactivity for recovery from fatigue is outmoded. Active neurophysiological mechanisms regulate the sleep cycle in a manner similar to other circadian rhythms. The slow wave (NREM) part of the sleep cycle appears to be involved in recovery from muscular fatigue; the dreaming (REM) part appears to be involved in psychological adaptation to life events. Since most hypnotic drugs suppress REM sleep, they should be used after careful consideration of the possible psychological effects. For example, some depressions may be alleviated by agents which suppress dreaming at the cost of isolating the patient from his inner emotional life. Chloral hydrate, chlordiazepoxide, and diazepam avoid this problem because they do not affect REM sleep. Some sleep disorders like severe nightmares may be treated by suppressing deep NREM sleep. Other disorders like enuresis and narcolepsy appear to be psychosomatic conditions and require a medical psychological-approach. There is some evidence that methods which increase or substitute for REM sleep may eventually be useful in facilitating emotional adjustment.

Drug-induced changes in fetal breathing activity and sleep state

1983 ◽  
Vol 61 (4) ◽  
pp. 315-324 ◽  
Author(s):  
Arno H. Jansen ◽  
S. Ioffe ◽  
V. Chernick
Keyword(s):  
Rem Sleep ◽  
Femoral Vein ◽  
Nrem Sleep ◽  
Primary Response ◽  
Sleep State ◽  
Drug Induced ◽  
Fetal Breathing ◽  
Near Term ◽  
Induced Changes ◽  
Stimulation Of

Drugs reported to stimulate fetal breathing (FB) were injected into a femoral vein of near-term fetal iambs during rapid eye movement (REM) and non-REM (NREM) sleep. The primary response to NaCN, 0.25–0.5 mg, a dose which did not flatten the electrocorticogram, was a brief burst of gasping in any sleep state. When injected during REM sleep, NaCN caused the cessation of spontaneous FB and the onset of gasping. Stimulation of FB was observed infrequently. Caffeine (10 mg) and doxapram (3 mg) frequently caused an immediate change in sleep state or arousal. The incidence of FB increased concomitantly with a change to REM sleep or wakefulness (W), but FB still ceased with the onset of NREM sleep. When administered during an episode of spontaneous FB during REM sleep, both caffeine and doxapram caused stimulation of the frequency and depth of breathing. Pilocarpine (4 mg) caused arousal and gasping followed by prolonged vigorous breathing that was dependent on intact carotid sinus nerves, Indomethacin (120 mg over several hours) did not affect sleep states but induced FB in both NREM and REM sleep. In summary, in the fetus the primary effect of NaCN is to suppress spontaneous FB and induce gasping and the effects of pilocarpine, caffeine, and doxapram are intimately related to sleep states or arousal. Indomethacin causes the conversion from episodic fetal to continuous postnatal-type breathing. These data indicate the importance of assessing fetal state of consciousness in interpreting the respiratory response to drugs.

Covert REM sleep effects on REM mentation: Further methodological considerations and supporting evidence

2000 ◽  
Vol 23 (6) ◽  
pp. 1040-1057 ◽  
Author(s):  
Tore A. Nielsen
Keyword(s):  
Eye Movements ◽  
Future Development ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Explanatory Models ◽  
Supporting Evidence ◽  
Sleep State ◽  
Detailed Understanding ◽  
Methodological Considerations

Whereas many researchers see a heuristic potential in the covert REM sleep model for explaining NREM sleep mentation and associated phenomena, many others are unconvinced of its value. At present, there is much circumstantial support for the model, but validation is lacking on many points. Supportive findings from several additional studies are summarized with results from two new studies showing (1) NREM mentation is correlated with duration of prior REM sleep, and (2) REM sleep signs (eye movements, phasic EMG) occur frequently in NREM sleep. The covert REM sleep model represents one class of explanatory models that combines the two assumptions of mind-body isomorphism and a 1-gen mentation generator; its future development will depend largely upon a more detailed understanding of sleep state interactions and their contribution to mind-body isomorphisms.

Changes in ventilation and chest wall mechanics during sleep in normal adolescents

1981 ◽  
Vol 51 (3) ◽  
pp. 557-564 ◽  
Author(s):  
E. Tabachnik ◽  
N. L. Muller ◽  
A. C. Bryan ◽  
H. Levison
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Muscle Activity ◽  
Minute Ventilation ◽  
Nrem Sleep ◽  
Work Load ◽  
Sleep State ◽  
Rib Cage ◽  
Diaphragmatic Muscle ◽  
Normal Adolescents

The effect of sleep state on ventilation and the mechanics of breathing was studied in nine normal adolescents by use of a respiratory inductive plethysmograph and surface electromyogram electrodes. Minute ventilation was state dependent (P less than 0.01), decreasing by a mean of 8% from wakefulness to nonrapid-eye-movement (NREM) sleep and increasing 4% from NREM to rapid-eye-movement (REM) sleep. These changes were caused by changes in respiratory rate. Tidal volume (VT) was not affected by sleep state (P greater than 0.10). The pattern of breathing during wakefulness was similar to that of REM sleep. During NREM sleep intercostal and diaphragmatic muscle activity increased by a mean of 34% and 11%, respectively, as compared with wakefulness, indicating an increase in the respiratory work load. This was accompanied by a substantial increase in rib cage contribution to VT. REM sleep was associated with a marked decrease in intercostal muscle activity (P less than 0.05) and a diminished rib cage contribution; VT was maintained due to a mean increase of 34% in diaphragmatic muscle activity (P less than 0.05).

scholarly journals Toward asleep DBS: Cortico basal-ganglia neural activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

2020 ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Rem Sleep ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Term Treatment ◽  
Sleep Cycle ◽  
Brain State ◽  
Long Term Treatment ◽  
Low Frequency Power ◽  
Frequency Power

Deep brain stimulation (DBS) is currently a standard long-term treatment for advanced motor symptoms in Parkinson's disease (PD). In an effort to enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two non-human primates under propofol, ketamine and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high frequency power and synchronization while propofol increases low frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low frequency oscillations used for physiological navigation toward basal ganglia DBS targets. The brain state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol imitates the NREM-REM sleep cycle. These promising results are the first step towards asleep DBS with non-distorted physiological navigation.

scholarly journals P142 Head flexion has the greatest impact on OSA severity during REM sleep

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A67-A68
Author(s):  
A Tate ◽  
V Kurup ◽  
B Shenoy ◽  
C Freakley ◽  
P Eastwood ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Interaction Effect ◽  
Head Rotation ◽  
Nrem Sleep ◽  
Outcome Variable ◽  
Sleep State ◽  
Respiratory Event ◽  
Supine Sleep ◽  
Logistic Mixed Effects Model ◽  
Head Flexion

Abstract Introduction Recent work has shown that head flexion has a modest worsening effect and head rotation has a modest protective effect on OSA severity. However, there is substantial variability both within and between individuals. In this analysis we aimed to identify if this variability is explained by sleep-state, BMI, age or sex. Methods 28 participants provided informed consent and were studied using diagnostic polysomnography with the addition of a customised, accelerometry based, head posture measurement device. For each epoch during supine sleep, the sleep state (NREM/REM), average head flexion (degrees) and average head rotation (degrees) were recorded. A logistic mixed effects model was fit across all epochs with the anthropometrics (BMI, sex, age), sleep state, average head flexion and average head rotation as explanatory variables with the absence/presence of one or more respiratory event(s) as the binary outcome variable. Results In total, 2122 of 5369 supine sleep epochs had a respiratory event. Three participants had no supine sleep. There were significant interaction effects for flexion-rotation, BMI-rotation and REM-flexion. The REM-flexion interaction effect was the strongest interaction effect with an odds ratio per 5 degrees of head flexion in REM sleep of 1.47 (95% CI: 1.13 – 1.86). Discussion Head flexion related worsening of OSA severity is greatest during REM sleep. This may be explained by attenuated upper airway neuromuscular activation in REM sleep compared with NREM sleep.

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