scholarly journals A Daytime Nap Enhances Visual Working Memory Performance and Alters Event-Related Delay Activity

2018 ◽  
Author(s):  
Kevin John MacDonald ◽  
Holly A. Lockhart ◽  
Alex C. Storace ◽  
Stephen Emrich ◽  
Kimberly A. Cote
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Visual Representations ◽  
Time On Task ◽  
Neural Processing ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Within Subjects ◽  
Daytime Nap

Working memory (WM) is impaired following sleep loss and may be improved after a nap. The goal of the current study was to better understand sleep-related WM enhancement by: 1) employing a WM task that assesses the ability to hold and report visual representations as well as the fidelity of the reports on a fine scale, 2) investigating neurophysiological properties of sleep and WM capacity as potential predictors or moderators of sleep-related enhancement, and 3) exploring frontal and occipital event-related delay activity to index the neural processing of stimuli in WM. In a within-subjects design, thirty-six young adults (Mage = 20, 20 men, 16 women) completed a 300-trial, continuous-report task of visual WM following a 90-min nap opportunity and an equivalent period of wakefulness. Mixed-effect models were used to estimate the odds of successful WM reports and the fidelity of those reports. The odds of a successful report were approximately equal between nap and wake conditions at the start of the task, but by the end, the odds of success were 1.26 times greater in the nap condition. Successful WM reports were more accurate after a nap, independent of time on task. Neither WM capacity nor any of the sleep variables measured were found to significantly moderate the nap effect on WM. Lastly, amplitude of frontal and occipital delay activity was altered in the nap relative to the wake condition. The findings are discussed in relation to the role of sleep in sustained attention and contemporary models of visual WM.

scholarly journals Influence of Cognitive Reserve on Cognitive Trajectories: Role of Brain Pathologies

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012728
Author(s):  
Xuerui Li ◽  
Ruixue Song ◽  
Xiuying Qi ◽  
Hui Xu ◽  
Wenzhe Yang ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Function ◽  
Episodic Memory ◽  
Cognitive Reserve ◽  
Late Life ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Global Cognition

Background and Objectives:Evidence on the association of the cognitive reserve (CR) with the cognitive trajectories is limited. We aimed to examine the influence of CR indicator on domain-specific cognitive trajectories taking brain pathologies into account.Methods:Within the Rush Memory and Aging Project, 1,697 dementia-free participants (mean age: 79.6 years) were followed up to 21 years. CR indicator encompassing education, early-life, mid-life, and late-life cognitive activities, and late-life social activity was ascertained at baseline and categorized as tertiles (the lowest, middle, and highest). Global cognition, episodic memory, semantic memory, working memory, visuospatial ability, and perceptual speed were assessed annually with 19 tests, from which composite scores were derived. During the follow-up, 648 died and underwent autopsies to evaluate brain pathologies. Data were analyzed using linear mixed-effect models.Results:Among the participants, the score of the CR indicator ranged from -8.00 to 5.74 (mean: 0.00±2.23). In multi-adjusted mixed-effect models, compared to the lowest CR, the highest was related to a slower decline in global cognition (β=0.028, 95% confidence interval [CI]: 0.012 to 0.043), episodic memory (β=0.028, 95% CI: 0.010 to 0.047) and working memory (β=0.019, 95% CI: 0.005 to 0.033) during the follow-up. In brain pathological data analysis, the association of the highest CR with cognitive function changes remained significant among participants with high Alzheimer’s disease pathology or gross infarcts.Discussion:High CR indicator is associated with preserved global cognitive function, episodic memory, and working memory, even in the presence of brain pathologies. Our findings highlight the important role of high CR accumulation in the prevention of cognitive decline.

scholarly journals Autonomic activity during sleep predicts memory consolidation in humans

2016 ◽  
Vol 113 (26) ◽  
pp. 7272-7277 ◽  
Author(s):  
Lauren N. Whitehurst ◽  
Nicola Cellini ◽  
Elizabeth A. McDevitt ◽  
Katherine A. Duggan ◽  
Sara C. Mednick
Keyword(s):  
Memory Consolidation ◽  
Memory Performance ◽  
Sleep Stages ◽  
Remote Associates Test ◽  
Daytime Nap ◽  
The Relationship ◽  
With Memory ◽  
Good Sleep ◽  
Variance Explained

Throughout history, psychologists and philosophers have proposed that good sleep benefits memory, yet current studies focusing on the relationship between traditionally reported sleep features (e.g., minutes in sleep stages) and changes in memory performance show contradictory findings. This discrepancy suggests that there are events occurring during sleep that have not yet been considered. The autonomic nervous system (ANS) shows strong variation across sleep stages. Also, increases in ANS activity during waking, as measured by heart rate variability (HRV), have been correlated with memory improvement. However, the role of ANS in sleep-dependent memory consolidation has never been examined. Here, we examined whether changes in cardiac ANS activity (HRV) during a daytime nap were related to performance on two memory conditions (Primed and Repeated) and a nonmemory control condition on the Remote Associates Test. In line with prior studies, we found sleep-dependent improvement in the Primed condition compared with the Quiet Wake control condition. Using regression analyses, we compared the proportion of variance in performance associated with traditionally reported sleep features (model 1) vs. sleep features and HRV during sleep (model 2). For both the Primed and Repeated conditions, model 2 (sleep + HRV) predicted performance significantly better (73% and 58% of variance explained, respectively) compared with model 1 (sleep only, 46% and 26% of variance explained, respectively). These findings present the first evidence, to our knowledge, that ANS activity may be one potential mechanism driving sleep-dependent plasticity.

scholarly journals The role of incubator classification on performance of incubators in Kenya.

2021 ◽  
Vol 10 (6) ◽  
pp. 256-267
Author(s):  
Miriti Jane Kinya ◽  
Kenneth Lawrance Wanjau ◽  
Nyagweth Ebenezer Odeyo
Keyword(s):  
Fixed Effects ◽  
Selection Criteria ◽  
Primary Data ◽  
Cross Sectional ◽  
Mixed Effect ◽  
Study Objective ◽  
Mixed Effect Models ◽  
Random Slopes ◽  
Linear Mixed Effect Models

The study sought to assess the importance of classifying incubators based on the programs offered for optimum performance. Client selection criteria were assessed through three constructs namely: models that fit program goals, uniqueness of ideas, and standard selection tool. A mixed cross-sectional and causal design was adopted and a census was carried out targeting all the 51 incubators. Primary data was collected with an incubator program as a grouping/ cluster variable yielding a multilevel data structure with incubator centres nested in programs. Linear mixed effect models were fitted using Stata to assess the study objective taking into account the fixed effects for the incubator centre level (level-1) and random effects for the program level (level-2). The uniqueness of ideas was found to have a significant fixed effect on performance at level one while at level two, the study found significant random intercepts of incubator centre performance across the programs. Models that match program goals and standard selection tools were also found to have significant random slopes as level two random covariates in the model. Based on the findings of significant random slopes, the study concluded that incubator classification is key for client selection criteria and enhances incubator performance.

scholarly journals Mate Availability and Sexual Disgust

2020 ◽  
Author(s):  
Courtney L. Crosby ◽  
Patrick Durkee ◽  
Anna Sedlacek ◽  
David M. Buss
Keyword(s):  
Mate Choice ◽  
Mate Selection ◽  
Local Environment ◽  
Relationship Status ◽  
Mixed Effect ◽  
Mate Availability ◽  
Mixed Effect Models ◽  
Sexual Disgust ◽  
Linear Mixed Effect Models

Objective: One of the factors that sexual disgust should be calibrated to is the size of the mating pool. Previous research provides evidence that low mate availability affects perceptions related to mate choice. However, methodological shortcomings leave the role of sexual disgust in facilitating mate selection unclear. We will examine whether perceptions of mate availability explain variance in levels of sexual disgust towards potential mates.Methods: Participants (N = 1,000) will rate how sexually disgusting they find 60 potential mates that have previously been rated on attractiveness by a separate group of raters. We will measure participants’ perceptions of mate availability in their local environment, self-perceived attractiveness and mate value, and relevant control variables (e.g., age, relationship status). Results: We will use linear mixed effect models to examine (1) the association between sexual disgust towards potential mates and perceived mate availability; (2) the sex difference in sexual disgust; (3) the association between targets’ attractiveness and raters’ sexual disgust; and (4) whether perceived mate availability moderates the association between sexual disgust and targets’ attractiveness. Conclusions: This study will test perceptions of mate availability as an input into the calibration of sexual disgust. The results will clarify the magnitude of mate availability perceptions on mate choice.

scholarly journals Reviewing the Role of Cognitive Load, Expertise Level, Motivation, and Unconscious Processing in Working Memory Performance

2015 ◽  
Vol 4 (2) ◽  
pp. 142 ◽  
Author(s):  
Seffetullah Kuldas ◽  
Shahabuddin Hashim ◽  
Hairul Nizam Ismail ◽  
Zainudin Abu Bakar
Keyword(s):  
Working Memory ◽  
Emotional Processing ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Cognitive Learning ◽  
Learning Task ◽  
Cognitive Capacity ◽  
Unconscious Processing ◽  
Expertise Level

<p class="p1">Human cognitive capacity is unavailable for conscious processing of every amount of instructional messages. Aligning an instructional design with learner expertise level would allow better use of available working memory capacity in a cognitive learning task. Motivating students to learn consciously is also an essential determinant of the capacity usage. However, motivational factors are often subject to unconscious rather than conscious emotional processing. This review sets out the need for further studies to elucidate the role of motivation and unconscious processing in the use of cognitive capacity<span class="s1">. </span></p>

scholarly journals Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0125752 ◽  
Author(s):  
Esther Yuet Ying Lau ◽  
Mark Lawrence Wong ◽  
Kristy Nga Ting Lau ◽  
Florence Wai Ying Hui ◽  
Chia-huei Tseng
Keyword(s):  
Working Memory ◽  
Eye Movement ◽  
Memory Performance ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Daytime Nap

scholarly journals Selenium level is associated withapoE ε4in rural elderly Chinese

2009 ◽  
Vol 12 (12) ◽  
pp. 2371-2376 ◽  
Author(s):  
Sujuan Gao ◽  
Yinlong Jin ◽  
Kathleen S Hall ◽  
Chaoke Liang ◽  
Frederick W Unverzagt ◽  
...  
Keyword(s):  
Random Effect ◽  
Rural Elderly ◽  
Mixed Effect ◽  
Apoe Ε4 ◽  
Mixed Effect Models ◽  
Significant Difference ◽  
Elderly Chinese ◽  
Chinese Cohort ◽  
And Gender

AbstractObjectiveSe is an essential trace element in human nutrition associated with antioxidant activity. Previous studies on predictors of toenail Se or serum Se have mostly concentrated on demographic factors such as age and gender. The present paper examines the association betweenapoEgenotype and Se levels in nail samples in a rural elderly Chinese cohort.DesignTwo thousand Chinese aged 65 years and over from four counties in China were enrolled in a cohort to study the association of Se with cognitive decline. Nail samples were collected from each participant and analysed for Se levels. Dietary Se intake was estimated from an FFQ using Se contents measured in food items collected from each village. Blood samples on filter cards were collected and analysed forapoEgenotype. Mixed-effect models were constructed with nail Se level as the dependent variable and each village as the random effect, which controlled for the potential confounding effect from correlation in Se measures obtained from participants residing in the same village.ResultsIn this elderly Chinese cohort, carriers of theapoE ε4allele had significantly lower Se levels measured in nail samples than non-carriers after adjusting for other significant covariates and controlling for estimated dietary Se intake. There was no significant difference between the two genotypes on estimated Se dietary intake (P= 0·6451).ConclusionsFuture studies are needed to examine the mechanism underlying the association between theapoE ε4allele and Se levels, including the role of oxidative stress and that of reduced lipid metabolism in theapoE ε4carriers.

scholarly journals 0632 Time of Day and Time on Task Effects on Working Memory and Sleepiness of Bus Drivers

SLEEP ◽  
2019 ◽  
Vol 42 (Supplement_1) ◽  
pp. A252-A252
Author(s):  
Maryam Maghsoudipour ◽  
Ramin Moradi ◽  
Mostafa Pouyakian ◽  
Mehdi Yaseri ◽  
Sara Moghimi
Keyword(s):  
Working Memory ◽  
Epworth Sleepiness Scale ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Digit Span ◽  
Memory Performance ◽  
Time Of Day ◽  
Time On Task ◽  
Bus Drivers ◽  
Wechsler Adult Intelligence

Abstract Introduction Fatigue and sleepiness have direct effects on vigilance, and cognitive functions of drivers. The objective of this study was to analyze individual bus drivers' characteristics and work shift parameters and relation to the working memory performance and sleepiness. Methods This prospective study was conducted on 35 inter-city bus drivers by convenience sampling. We collected data during the time span of a 24-hour round trip by using the demographic questionnaire, Epworth Sleepiness Scale (ESS), Karolinska Sleepiness Scale (KSS), and reversed digit span memory test (part of the Wechsler-Adult Intelligence Test). A linear mixed model was used for statistic analysis. Results The mean (± SD) of Epworth Sleepiness Scale score was 6.4 (±2.7). 12.5% of drivers had excessive daytime sleepiness according to ESS results. The circadian effect of time of day on the drivers' working memories was statistically significant (P=0.001), and the working memory was minimum at 04:00 am (± 1). Additionally, the differences in sleepiness at different times of day were statistically significant (P=0.001); with the highest score at 04:00 am (± 1). Time on task and time of sleep parameters did not show a significant effect on working memory (p> 0.05). Time on task parameter affected sleepiness significantly (p=0.024). Conclusion The circadian factor was the most important predictor of cognitive performance compared to time on task (fatigue) and time of sleep. Although, time on task had a significant effect on sleepiness and sleepiness significantly decreased working memory. We conclude that optimizing the drivers' schedule is the most important intervention to optimize drivers' performance and increase road safety. Support (If Any) Not

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