bluuebunny/crossref_metadata_2025_split huggingface dataset:
034 Dreaming as Constructive Episodic Future Simulation
Authors: Wamsley Erin 
Published: May 2021

Abstract

Introduction
Memories of the past help us respond to similar situations in the future. The “episodic future simulation” hypothesis proposes that waking thought combines fragments of various past episodes into imagined simulations of events that may occur in the future. We asked whether this framework from waking cognitive neuroscience may be useful for understanding the function of sleep and dreaming. We hypothesized that participants would commonly identify future events as the source of a dream. Further, we expected future-oriented dreams to draw on multiple different waking memories, with fragments of past experience combined into novel scenarios relevant to anticipated events in participants’ personal futures.

Methods
N=48 students spent the night in the laboratory with polysomnographic recording. During the night, participants were awakened up to 13 times to report on their experiences during sleep onset, REM and NREM sleep. The following morning, participants identified and described waking life sources for each dream reported the previous evening. A total of N=481 reports were analyzed.

Results
While dreams were most commonly traced to past memory (53.5% of reports), more than a quarter (25.7%) were related to specific impending future events. Nearly half of reports with a waking source were traced to multiple different sources (49.7%). Over a third of dreams with a future event source were additionally related to one or more specific past episodic memories (37.4% of all reports with a future episodic source). Future-oriented dreams became proportionally more common later in the night.

Conclusion
First, we confirm prior reports that dreams not only reflect past memory, but also anticipate probable future events. Furthermore, these data provide a novel description of how future-oriented dreams draw simultaneously from multiple waking-life sources, utilizing fragments of past experience to construct novel scenarios anticipating future events. The proportional increase of future-oriented dreams later in the night may be driven by temporal proximity to the events of the following day. While these dreams rarely depict future events realistically, the activation and recombination of future-relevant memory fragments may nonetheless serve an adaptive function.

Support (if any)
This work was supported by Bursaries award 83/12 from the BIAL Foundation.
049 The Effect of Obstructive Sleep Apnea on Emotional Memory Consolidation
Authors: Cunningham Tony , Kishore Divya , Guo Mengshuang , Igue Moroke , Malhotra Atul , Stickgold Robert , Djonlagic Ina 
Published: May 2021

Abstract

Introduction
A growing body of evidence suggests that sleep is critical for the processing and consolidation of emotional information into long-term memory. Previous research has indicated that emotional components of scenes particularly benefit from sleep in healthy groups, yet sleep dependent emotional memory processes remain unexplored in many clinical cohorts, including those with obstructive sleep apnea (OSA).

Methods
In this study, a group of newly diagnosed OSA patients (n=26) and a matched group of healthy controls (n=24) encoded scenes with negative or neutral foreground objects placed on neutral backgrounds prior to a night of polysomnographically recorded sleep. In the morning, they completed a recognition test in which objects and backgrounds were presented separately and one at a time.

Results
OSA patients have a deficit in both overall gist memory and the specific recognition memory for the scenes. Impairment of gist recognition was across all elements of the scenes, both negative and neutral objects and backgrounds [main effect of group: F(1,48) = 13.5, p=0.001], while specific recognition impairment was exclusively found for negative objects [t(48)=2.0, p=0.05]. Across all participants, successful gist recognition correlated positively with sleep efficiency (p=0.001) and REM sleep (p=0.009), while successful specific memory recognition correlated only with REM sleep (p=0.004).

Conclusion
Our findings indicate that fragmented sleep and reduced REM sleep, both hallmarks of OSA, significantly disrupt distinct memory processes for emotional content. Gist memory is universally impacted, while memory for specific details appears to have a greater deterioration for negative aspects of memories. These memory affects may have impacts on complex emotional processes, such as emotion regulation, and could contribute to the high comorbid depressive symptoms in OSA.

Support (if any)
The authors would like to thank the funding sources awarded to author ID for supporting this research: NIH grant # K23HL103850 and American Sleep Medicine Foundation grant #54-JF-10. Author TJC is currently funded by the Research Training Program in Sleep, Circadian and Respiratory Neurobiology (NIH T32 HL007901) through the Division of Sleep Medicine at Harvard Medical School and Brigham & Women’s Hospital.
050 Evening Alcohol Consumption and Slow Wave Sleep: Impact on Morning Hippocampus-Dependent Learning across Three Nights
Authors: Elkhadem Alexandria , Saletin Jared , Gredvig-Ardito Caroline , McGeary John , Carskadon Mary 
Published: May 2021

Abstract

Introduction
Numerous studies interrogated the relationship between alcohol and a single night of sleep. Yet, many adults engage in cumulative days of drinking. Previous studies show alcohol on a single night increases slow wave sleep in the first third of night. Similarly, sleep has been associated with the success of daytime learning. Our goal was to investigate across three consecutive nights how evening alcohol use and nighttime sleep are associated with morning learning.

Methods
23 adults (11F, mean age 33.5±12 years) completed six nights of PSG monitored sleep. Participants consumed alcohol with a target 0.08 breath alcohol concentration (BrAC) and no alcohol on three consecutive nights in counterbalanced order. Percent of slow wave sleep (SWS%) in the first third of the night was derived. Learning was assessed each morning with distinct stimuli on the Mnemonic Similarity Task (MST). The MST score derived was the Lure Discrimination Index (LDI), defined as the proportion of similar images correctly identified minus the proportion of old images incorrectly identified.

Results
SWS% during the first third of the night was greater for alcohol nights compared to non-alcohol nights (F(1, 110)=10.891, p=0.01). However, there was no evidence that either night number or the interaction of drink content and night number affected %SWS in the first third of night (all p’s &gt; 0.05). There was a modest decrease in LDI on mornings following alcohol consumption; however, this effect was not significant. In a separate linear mixed-effect model we found no evidence for an effect of night number, drink content, or their interaction on MST LDI scores (all p’s &gt; 0.05).

Conclusion
Our results indicate that slow wave sleep in the first third of the night is sensitive to evening alcohol consumption. Despite prior literature associating slow wave sleep with next-day learning, we observed no effect of alcohol or night number on morning learning. It is possible that the small sample size contributed to our results. There is little prior research on the cumulative effects of alcohol on sleep and learning; our study adds to this area of research despite the negative findings.

Support (if any)
R01AA025593
055 Novel sleep-dependent spatial memory and navigation task using Minecraft
Authors: Simon Katharine , Clemenson Gregory , Clayton Brandon , Zhang Jing , Alzueta Elisabet , Dulai Teji , Baker Fiona , Mednick Sara 
Published: May 2021

Abstract

Introduction
Spatial navigation and memory are hippocampally-dependent and decrease with age, yet, ecologically-valid methods remain elusive. We developed an engaging and inherently flexible spatial navigation/memory task using the Minecraft platform to test sleep-dependent memory. We validated baseline performance and learning rates across two separate Minecraft environments.

Methods
Using a within-subjects design, twenty-two subjects experienced two conditions (wake/sleep) and two Minecraft environments, counterbalanced across subjects. At encoding, subjects learned the locations of 12 objects. Memory for object location accuracy and navigation route (distance between start and target; vector: angle of direction towards target location from start) was tested immediately and following 12-hours of wake or sleep. Post-hoc analyses were conducted using a median split on subjects’ Immediate test performance.

Results
There were no significant differences across conditions for the Immediate test performance (t(22) = .567, p = .576) across the two environments. Delayed test showed greater improvement in accuracy after sleep compared to wake (t(18) = 2.795, p=.012), no differences in distance or vector. Median split by Immediate test performance revealed that initially lower performance showed the greatest improvement after delay in the sleep group (t(18) = 2.818, p =.011), but not the wake group (t(18) = -1.051, p =.308). Additionally, these same subjects’ vector direction was initially worse at Immediate Test (t(18) = -2.9, p = .01), and improved with sleep, becoming equivalent to the better performers at Delay test (t(18) = -.336, p = .74).

Conclusion
We demonstrate a novel spatial navigation/memory tasks using Minecraft that shows sleep-dependent learning across two distinct environments. We showed enhancement of spatial location accuracy after a night of sleep compared to wake. We further demonstrate that with sleep, those with worse initial performance show the greatest memory and navigation improvement, consistent with other findings that sleep supports enhancement of weaker memories and extended to the spatial-domain. This novel platform can be used to evaluate spatial memory across the lifespan and within special clinical populations.

Support (if any)
NIH R01 AG061355
073 Whole-brain network analysis of neural oscillations during light sleep
Authors: Fan Joline , Kudo Kiwamu , Ranasinghe Kamalini , Morise Hirofumi , Findlay Anne , Kirsch Heidi , Krystal Andrew , Nagarajan Srikantan 
Published: May 2021

Abstract

Introduction
Sleep is a highly stereotyped phenomenon that is ubiquitous across species. Although behaviorally appearing as a homogeneous process, sleep has been recognized as cortically heterogenous and locally dynamic. PET/fMRI studies have provided key insights into regional activation and deactivation with sleep onset, but they lack the high temporal resolution and electrophysiology for understanding neural interactions. Using simultaneous electrocorticography (EEG) and magnetoencephalography (MEG) imaging, we systematically characterize whole-brain neural oscillations and identify frequency specific, cortically-based patterns associated with sleep onset.

Methods
In this study, 14 healthy subjects underwent simultaneous EEG and MEG imaging. Sleep states were determined by scalp EEG. Eight 15s artifact-free epochs, e.g. 120s sensor time series, were selected to represent each behavioral state: N1, N2 and wake. Atlas-based source reconstruction was performed using adaptive beamforming methods. Functional connectivity measures were computed using imaginary coherence and across regions of interests (ROIs, segmentation of 210 cortical regions with Brainnetome Atlas) in multiple frequency bands, including delta (1-4Hz), theta (4-8Hz), alpha (8-12Hz), sigma (12-15Hz), beta (15-30Hz), and gamma (30-50Hz). Directional phase transfer entropy (PTE) was also evaluated to determine the direction of information flow with transition to sleep.

Results
We show that the transition to sleep is encoded in a spatially and temporally specific dynamic pattern of whole-brain functional connectivity. With sleep onset, there is increased functional connectivity diffusely within the delta frequency, while spatially specific profiles in other frequency bands, e.g. increased fronto-temporal connectivity in the alpha frequency band and fronto-occipital connectivity in the theta band. In addition, rather than a decoupling of anterior-posterior regions with transition to sleep, there is a spectral shift to delta frequencies observed in the synchrony and information flow of neural activity.

Conclusion
Sleep onset is cortically heterogeneous, composed of spatially and temporally specific patterns of whole-brain functional connectivity, which may play an essential role in the transition to sleep.

Support (if any)
Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the NIH under Award Number (5TL1TR001871-05 to JMF). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.
075 Systematic Individual Differences in Vulnerability to Sleep Inertia
Authors: Lundholm Kirsie , Van Dongen Hans , Honn Kimberly 
Published: May 2021

Abstract

Introduction
Sleep inertia (SI), the transient grogginess and disorientation that occurs upon awakening, may be particularly problematic in on-call operations that require safety-sensitive and time-critical action, such as healthcare and emergency response. The magnitude of SI is determined by multiple factors, including sleep history, and anecdotal evidence suggests individuals may differ considerably in susceptibility to impairment from SI.

Methods
As part of a larger study investigating individual differences in neurobehavioral impairment, N=21 healthy adults (aged 21–38y; 9 females) completed three laboratory-based neurobehavioral testing sessions, each preceded by baseline sleep. Baseline sleep and nightly at-home sleep opportunities during the week prior were either 12h (extended) or 6h (restricted); two sessions involved extension and one involved restriction in randomized, counterbalanced order. Baseline sleep opportunities ended at 10:00, whereupon subjects completed a 60min neurobehavioral test battery, which began with the Karolinska Sleepiness Scale (KSS). The test battery was repeated every 2h throughout the testing sessions.

Results
A nonlinear mixed-effects regression, controlling for prior sleep restriction/extension and session number, was used to estimate the subjective magnitude of SI immediately upon awakening from baseline sleep, as measured by KSS scores, and the exponential dissipation rate of the effect relative to KSS scores later in the day (12:00-20:00). Following prior sleep extension, SI was associated with a 1.82±0.59 KSS score increase (p=0.006), which subsequently dissipated from a level of 4.80±0.65 to 2.98±0.29 (p=&lt;0.001) later in the day. Following prior sleep restriction, SI was associated with a 1.58±0.58 KSS score increase (p=0.014), which subsequently dissipated from a level of 5.39±0.63 to 3.80±0.30 later in the day. SI took ~45min to dissipate to a negligible level based on a time constant estimate of 23.6±15.8min. Importantly, there were substantial, systematic individual differences in the magnitude of SI, with a between-subjects standard deviation of 1.15±0.42 points on the KSS (ICC=0.51, F=19.5, p&lt;0.001).

Conclusion
We observed sizeable, systematic individual differences in subjective sleepiness due to sleep inertia. To what degree these individual differences predict objective performance deficits remains to be investigated.

Support (if any)
NASA grant NAG9-1161 and CDMRP grant W81XWH-20-1-0442
080 Is Napping Only Beneficial to Evening Chronotypes? A Pilot Study
Authors: Zamore Zachary , Goldschmied Jennifer , Deldin Patricia 
Published: May 2021

Abstract

Introduction
Research shows associations between chronotype and behavior. While eveningness is associated with lower levels of self-control, morningness is associated with increased conscientiousness. Additionally, throughout the day, the increase in homeostatic sleep pressure due to wakefulness can affect executive functioning, including emotional regulation. Napping is an effective countermeasure to sleepiness and associated emotional dysregulation, but the impact of chronotype on this benefit is unknown. Therefore, this study aimed to examine the impact of chronotype and a midday nap on an aspect of emotional regulation: frustration tolerance.

Methods
40 participants between the ages of 18–50 were randomized into a 60-minute, midday nap or no-nap condition. Chronotype was measured using the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ). Frustration tolerance (FT) was measured pre and post nap using an adaption of Feather’s frustration tolerance task where FT was measured as the time spent on an impossible task. To examine the association of chronotype and FT, correlational analysis was used. Chronotype was also determined using a median split of the MEQ due to few true morning and evening types in the sample. This data was then subjected to a repeated measures ANOVA with condition (pre or post-nap) as a within-subjects factor and group (nap or no-nap; high or low MEQ score) as between-subject factors.

Results
Results revealed a significant correlation between MEQ score and change in time spent on the impossible task, with those with lower MEQ scores (more evening) showing an increase in time spent on the impossible task, r(20) = -.51, p = .016. Similarly, results of the ANOVA revealed a significant condition (pre or post-nap) by group (nap, no nap; high, low MEQ) interaction, F(1,1) = 4.694, p = .039, such that, those in the nap group with lower MEQ (more evening) spent more time on the impossible task following the nap.

Conclusion
Our results indicate that chronotype may impact a nap’s positive effect on emotional regulation, with greater benefit for those with the eveningness chronotype. Because napping is currently practiced by 1/3 of American adults, from a personalized medicine perspective, it’s imperative that its chronotype-dependent benefits be investigated further to effectively guide evidence-based recommendations.
Support (if any):
086 Sleep midpoint after job loss predicts breakfast skipping patterns
Authors: Callovini Leah , Gubka Gaby , Mayer Candace , Rojo-Wissar Darlynn , Glickenstein David , Thomson Cynthia , Quan Stuart , Silva Graciela , Haynes Patricia 
Published: May 2021

Abstract

Introduction
Few studies have examined circadian phase after job loss, an event that upends daily routine. It is common that a daily routine begins with the consumption of breakfast, and breakfast behavior may contribute to health status in adults. Therefore, we sought to examine whether a later midpoint of sleep was associated with breakfast skipping among adults whose schedules were no longer dictated by employment.

Methods
Data were obtained from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study. The sample of 155 participants had involuntarily lost their jobs in the last 90 days. Both cross-sectional and 18-month longitudinal analyses assessed the relationship between sleep midpoint after job loss and current and later breakfast skipping. Assessment periods were 14 days. Sleep was measured via actigraphy, and breakfast skipping was measured via daily diary (1 = had breakfast; 0 = did not have breakfast). The midpoint of sleep was calculated as the circular center based on actigraphy sleep onset and offset times.

Results
The midpoint of sleep at baseline was negatively associated with breakfast consumption at baseline (B = -.09, SE = .02, p = .000). Also, a later midpoint was associated with breakfast skipping over the next 18 months (estimate = -.08; SE = .02; p = .000). Prospective findings remained significant when adjusting for gender, ethnicity, age, perceived stress, body mass index (BMI), education, and reemployment over time. Education (estimate = 14.26, SE = 6.23, p &lt; .05) and BMI (estimate = -.51, SE = .25, p &lt; .05) were the only significant covariates. No other sleep indices predicted breakfast behavior cross-sectionally or prospectively.

Conclusion
Consistent with research in adolescents, unemployed adults with a later circadian phase are more likely to skip breakfast more often. Breakfast skipping was also associated with higher BMI. Taken together, these findings provide support for the future testing of sleep/wake scheduling interventions to modify breakfast skipping and potentially mitigate weight gain after job loss.

Support (if any)
#1R01HL117995-01A1
103 Young Adult’s Sleep Efficiency is Positively Related to Risky Decision- Making in Novel BART
Authors: Duby Nicole , Mizell Jack Morgan , Huskey Alisa , Wardle Sophie Pinkston , Taylor Daniel , Wilson Robert 
Published: May 2021

Abstract

Introduction
Numerous studies have indicated that poor sleep quality is relatively common among young adults and is related to less than optimal decision-making behavior. In order to assess decision-making behavior, we utilize a new variant of a Balloon Analogue Risk Task (BART) to assess sleep efficiency and other self-report measures’ relation to risky decision-making in young adults. We hypothesize that individuals who have poorer sleep will make more risky decisions than those who have better sleep in a novel measure called the One-Shot BART.

Methods
200 undergraduate participants were recruited from the University of Arizona Psychology subject pool. Participants completed sleep quality questionnaires including the Sleep Condition Indicator and Split-Week Self-Assessment of Sleep-Y. Participants also completed a battery of self-report measures to assess exposure to traumatic events and trauma-related symptoms through the PTSD Checklist and Adverse Childhood Experiences Questionnaire. Lastly, participants were also tasked with completing a novel risk-taking task measure (the One-Shot BART) to assess risk-taking propensity and elucidate the cognitive processes underlying the risk-taking behavior. This task showed a significant correlation with (r=.24, p&lt;.05) real-world risk measures from the RISQ assessment.

Results
We found that better sleep efficiency showed a positive relationship with risk-taking(r=21, p&lt;.05) in the BART, in conflict with our initial hypothesis that better sleep would lead to less risk-taking. However, in the BART some level of risk-taking is necessary to do well in the task, so risk-taking is beneficial. We found that those people with lower levels of sleep efficiency also performed more randomly in the BART (p&lt;.05), showing that a lack of sleep affects noise in the decision process, which is also supported by our finding showing that people with lower sleep efficiency also show a higher level of response time variability (p&lt;.05).

Conclusion
Behavioral results from the One-Shot BART are affected by Sleep Efficiency in a college student population. Interestingly, Sleep Efficiency was positively correlated with risky decision making in the One-Shot BART, indicating more optimal risk-taking in the game that may be mirrored in real-world decisions.
Support (if any):