scholarly journals Does Sleep Promote False Memories?

2011 ◽  
Vol 23 (1) ◽  
pp. 26-40 ◽  
Author(s):  
Annabelle Darsaud ◽  
Hedwige Dehon ◽  
Olaf Lahl ◽  
Virginie Sterpenich ◽  
Mélanie Boly ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Memory Consolidation ◽  
Declarative Memory ◽  
False Memories ◽  
Retrosplenial Cortex ◽  
New Words ◽  
Brain Responses ◽  
Fmri Session ◽  
Significant Difference ◽  
Lack Of Sleep

Memory is constructive in nature so that it may sometimes lead to the retrieval of distorted or illusory information. Sleep facilitates accurate declarative memory consolidation but might also promote such memory distortions. We examined the influence of sleep and lack of sleep on the cerebral correlates of accurate and false recollections using fMRI. After encoding lists of semantically related word associates, half of the participants were allowed to sleep, whereas the others were totally sleep deprived on the first postencoding night. During a subsequent retest fMRI session taking place 3 days later, participants made recognition memory judgments about the previously studied associates, critical theme words (which had not been previously presented during encoding), and new words unrelated to the studied items. Sleep, relative to sleep deprivation, enhanced accurate and false recollections. No significant difference was observed in brain responses to false or illusory recollection between sleep and sleep deprivation conditions. However, after sleep but not after sleep deprivation (exclusive masking), accurate and illusory recollections were both associated with responses in the hippocampus and retrosplenial cortex. The data suggest that sleep does not selectively enhance illusory memories but rather tends to promote systems-level consolidation in hippocampo-neocortical circuits of memories subsequently associated with both accurate and illusory recollections. We further observed that during encoding, hippocampal responses were selectively larger for items subsequently accurately retrieved than for material leading to illusory memories. The data indicate that the early organization of memory during encoding is a major factor influencing subsequent production of accurate or false memories.

036 The Effect of Exercise on Sleep Architecture and Memory Consolidation during a Daytime Nap

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A16-A16
Author(s):  
Megan Collins ◽  
Erin Wamsley ◽  
Hailey Napier ◽  
Madeline Ray
Keyword(s):  
Slow Wave ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Declarative Memory ◽  
Sleep Stage ◽  
Sleep Time ◽  
Learning Task ◽  
Memory Retention ◽  
Verbal Information ◽  
Significant Difference

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):

A Genetic Polymorphism of the Human Dopamine Transporter Determines the Impact of Sleep Deprivation on Brain Responses to Rewards and Punishments

2016 ◽  
Vol 28 (6) ◽  
pp. 803-810 ◽  
Author(s):  
Stephanie M. Greer ◽  
Andrea N. Goldstein ◽  
Brian Knutson ◽  
Matthew P. Walker
Keyword(s):  
Genetic Polymorphism ◽  
Sleep Deprivation ◽  
Dopamine Transporter ◽  
Sleep Loss ◽  
Functional Polymorphisms ◽  
Motivated Behavior ◽  
Brain Responses ◽  
Lack Of Sleep ◽  
Gains And Losses ◽  
The Impact

Despite an emerging link between alterations in motivated behavior and a lack of sleep, the impact of sleep deprivation on human brain mechanisms of reward and punishment remain largely unknown, as does the role of trait dopamine activity in modulating such effects in the mesolimbic system. Combining fMRI with an established incentive paradigm and individual genotyping, here, we test the hypothesis that trait differences in the human dopamine transporter (DAT) gene—associated with altered synaptic dopamine signalling—govern the impact of sleep deprivation on neural sensitivity to impending monetary gains and losses. Consistent with this framework, markedly different striatal reward responses were observed following sleep loss depending on the DAT functional polymorphisms. Only participants carrying a copy of the nine-repeat DAT allele—linked to higher phasic dopamine activity—expressed amplified striatal response during anticipation of monetary gain following sleep deprivation. Moreover, participants homozygous for the ten-repeat DAT allele—linked to lower phasic dopamine activity—selectively demonstrated an increase in sensitivity to monetary loss within anterior insula following sleep loss. Together, these data reveal a mechanistic dependency on human of trait dopaminergic function in determining the interaction between sleep deprivation and neural processing of rewards and punishments. Such findings have clinical implications in disorders where the DAT genetic polymorphism presents a known risk factor with comorbid sleep disruption, including attention hyperactive deficit disorder and substance abuse.

Effects of Acute Sleep Deprivation on Working Memory Capacity in Undergraduate Students

2021 ◽  
pp. 1-11
Author(s):  
Sandeep Nelabhotla ◽  
Surya Shanmugam
Keyword(s):  
Working Memory ◽  
Sleep Deprivation ◽  
Undergraduate Students ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Significant Difference ◽  
Lack Of Sleep ◽  
Acute Sleep Deprivation ◽  
Spatial Test

Sleep is a necessary staple in our everyday lives but with advancements in society and an increase in day to day commitments it feels as though there is not enough time in the day. One of the first things to be forsaken in the hopes of maintaining a work schedule or routine is sleep. While the lack of sleep is disproportionate in most demographics, in university students in particular, a lack of sleep is a common, consistent, and necessary plague. Students can be under the impression that the effects of sleep deprivation have mostly long-term repercussions; however, prior literature has indicated that sleep deprivation impacts not just long-term consolidation but also significantly affects memory in the short-term, specifically the working memory (Xie et al. 2019; Chee et al., 2006). In this investigation, we seek to understand the effects that acute sleep deprivation has on the working memory capacity of individuals using a 2-back spatial test. A sample of convenience of upper-class undergraduate students was chosen and the participants were asked to take a specific 2-back spatial test - twice on a day that they subjectively felt as having a regular sleep schedule and twice on a day that they subjectively felt as having sleep deprivation. The team predicted that working memory 2-back task scores will be adversely affected by sleep deprivation. While there was a statistically significant difference in the working memory scores on the full sample level, this was not reflected on the individual level. This indicates that the effects of sleep deprivation are not generalizable to a full population and that they must be reviewed on a case-by-case basis. Furthermore, since greater variation was observed in the sleep deprived scores in all individuals, it implies that sleep deprivation may indirectly affect the consistency of working memory by affecting attention span and concentration.

scholarly journals Hippocampus-retrosplenial cortex interaction is increased during phasic REM and contributes to memory consolidation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Gomes de Almeida-Filho ◽  
Bruna Del Vechio Koike ◽  
Francesca Billwiller ◽  
Kelly Soares Farias ◽  
Igor Rafael Praxedes de Sales ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Memory Consolidation ◽  
Retrosplenial Cortex ◽  
Contextual Fear Conditioning ◽  
Oscillatory Activity ◽  
Theta Oscillation ◽  
Contextual Fear ◽  
Before And After ◽  
Freely Behaving ◽  
Phasic Rem Sleep

AbstractHippocampal (HPC) theta oscillation during post-training rapid eye movement (REM) sleep supports spatial learning. Theta also modulates neuronal and oscillatory activity in the retrosplenial cortex (RSC) during REM sleep. To investigate the relevance of theta-driven interaction between these two regions to memory consolidation, we computed the Granger causality within theta range on electrophysiological data recorded in freely behaving rats during REM sleep, both before and after contextual fear conditioning. We found a training-induced modulation of causality between HPC and RSC that was correlated with memory retrieval 24 h later. Retrieval was proportional to the change in the relative influence RSC exerted upon HPC theta oscillation. Importantly, causality peaked during theta acceleration, in synchrony with phasic REM sleep. Altogether, these results support a role for phasic REM sleep in hippocampo-cortical memory consolidation and suggest that causality modulation between RSC and HPC during REM sleep plays a functional role in that phenomenon.

Pharmacologically Increasing Sleep Spindles Enhances Recognition for Negative and High-arousal Memories

2013 ◽  
Vol 25 (10) ◽  
pp. 1597-1610 ◽  
Author(s):  
Erik J. Kaestner ◽  
John T. Wixted ◽  
Sara C. Mednick
Keyword(s):  
Rem Sleep ◽  
Memory Consolidation ◽  
Declarative Memory ◽  
Memory Performance ◽  
Emotional Memory ◽  
Limited Range ◽  
Sleep Spindles ◽  
Sleep Spindle ◽  
Emotional Stimuli ◽  
Valence And Arousal

Sleep affects declarative memory for emotional stimuli differently than it affects declarative memory for nonemotional stimuli. However, the interaction between specific sleep characteristics and emotional memory is not well understood. Recent studies on how sleep affects emotional memory have focused on rapid eye movement sleep (REM) but have not addressed non-REM sleep, particularly sleep spindles. This is despite the fact that sleep spindles are implicated in declarative memory as well as neural models of memory consolidation (e.g., hippocampal neural replay). Additionally, many studies examine a limited range of emotional stimuli and fail to disentangle differences in memory performance because of variance in valence and arousal. Here, we experimentally increase non-REM sleep features, sleep spindle density, and SWS, with pharmacological interventions using zolpidem (Ambien) and sodium oxybate (Xyrem) during daytime naps. We use a full spread of emotional stimuli to test all levels of valence and arousal. We find that increasing sleep spindle density increases memory discrimination (da) for highly arousing and negative stimuli without altering measures of bias (ca). These results indicate a broader role for sleep in the processing of emotional stimuli with differing effects based on arousal and valence, and they raise the possibility that sleep spindles causally facilitate emotional memory consolidation. These findings are discussed in terms of the known use of hypnotics in individuals with emotional mood disorders.

scholarly journals Sleep Deprivation and Sleep-Onset Insomnia are Associated with Blunted Physiological Reactivity to Stressors

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 246-252
Author(s):  
Devon A Hansen ◽  
Brieann C Satterfield ◽  
Matthew E Layton ◽  
Hans P A Van Dongen
Keyword(s):  
Sleep Deprivation ◽  
Laboratory Study ◽  
Salivary Cortisol ◽  
Sleep Onset ◽  
Deprivation Condition ◽  
Increased Risk ◽  
Significant Difference ◽  
Sleep Deficiency ◽  
The Impact ◽  
Chronic Sleep

ABSTRACT Introduction Military operations often involve intense exposure to stressors combined with acute sleep deprivation, while military personnel also experience high prevalence of chronic sleep deficiency from insomnia and other sleep disorders. However, the impact of acute and chronic sleep deficiency on physiologic stressor responses is poorly understood. In a controlled laboratory study with normal sleepers and individuals with chronic sleep-onset insomnia, we measured responses to an acute stressor administered in a sleep deprivation condition or a control condition. Methods Twenty-two adults (aged 22-40 years; 16 females)—11 healthy normal sleepers and 11 individuals with sleep-onset insomnia—completed a 5-day (4-night) in-laboratory study. After an adaptation day and a baseline day, subjects were assigned to a 38-hour total sleep deprivation (TSD) condition or a control condition; the study ended with a recovery day. At 8:00 PM after 36 hours awake in the sleep deprivation condition or 12 hours awake in the control condition, subjects underwent a Maastricht Acute Stress Test (MAST). Salivary cortisol was measured immediately before the MAST at 8:00 PM, every 15 minutes after the MAST from 8:15 PM until 9:15 PM, and 30 minutes later at 9:45 PM. Baseline salivary cortisol was collected in the evening of the baseline day. Additionally, before and immediately upon completion of the MAST, self-report ratings of affect and pain were collected. Results The MAST elicited a stressor response in both normal sleepers and individuals with sleep-onset insomnia, regardless of the condition, as evidenced by increases in negative affect and pain ratings. Relative to baseline, cortisol levels increased immediately following the MAST, peaked 30 minutes later, and then gradually returned to pre-MAST levels. At the cortisol peak, there was a significant difference across groups and conditions, reflecting a pronounced blunting of the cortisol response in the normal sleepers in the TSD condition and the sleep-onset insomnia group in both the TSD and control conditions. Conclusions Blunted stressor reactivity as a result of sleep deficiency, whether acute or chronic, may reflect reduced resiliency attributable to allostatic load and may put warfighters at increased risk in high-stakes, rapid response scenarios.

scholarly journals Using Language Games for Vocabulary Retention in a Rural Primary School in Sarawak

2020 ◽  
Vol 4 (2) ◽  
pp. 101
Author(s):  
Lydia Zeta Donald Stavy ◽  
Frankie Subon ◽  
Norseha Unin
Keyword(s):  
English Language ◽  
Teaching Method ◽  
Language Games ◽  
Text Book ◽  
Vocabulary Retention ◽  
New Words ◽  
Conventional Teaching ◽  
Significant Difference ◽  
Post Test ◽  
The Impact

This study seeks to examine the impact of using language games on students’ vocabulary retention. Six language games were chosen for this study; (1) describe it, (2) matching pairs, (3) jigsaw puzzle, (4) board rush,(5) ball games and (6) true or false. The rationale for choosing six different games is based on the understanding that students require at least five to sixteen exposures to learn a new word (Nation’s, 2001) foreffective vocabulary retention. For this study, vocabulary retention is the ability to keep or retain the new words that are taught for the duration of two weeks. The Pre-test and post-test were used to measure the vocabularyretention of the students. Prior to the pre-test, all 64 participants were taught for two weeks using the conventional teaching method by getting students to look words up in the dictionary, write definitions, and use the words in sentences (Basurto, 2004).For this traditional teaching, the eight new words were chosen from unit 10 of the text book for grade three of Malaysian elementary schools. For the next stage, the students weretaught eight new words from unit 11 of the same text book. After two weeks of teaching using the above six games, the students were given the posttest. The findings revealed that there was a significant difference invocabulary retention between the pre-test and post-test. The participants were able to retain significantly more words in the post-test than in the pre-test. In fact, they achieved better results in the post-test (M=63.45) than in the pre-test (M=58.71). This study reveals that language games can help to boost the students’ vocabulary retention if they are given a chance to learn and practice English language in a fun learning environment.

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