Increased frequency of light physical activity during midlife and old age buffers against cognitive declines.

Although it is well established that moderate-to-vigorous physical activity (MVPA) buffers against declines in cognitive health, less is known about the benefits of light physical activity (LPA). Research on the role of LPA is crucial to advancing behavioral interventions to improve late life health outcomes, including cognitive functioning, because this form of physical activity remains more feasible and amenable to change in old age. Our study examined the extent to which increases in LPA frequency protected against longitudinal declines in cognitive functioning and whether such a relationship becomes pronounced in old age when opportunities for MVPA are typically reduced. We analyzed 9-year data from the national Midlife in the United States Study (n = 2,229; Mage = 56 years, range = 33-83; 56% female) using autoregressive models that assessed whether change in LPA frequency predicted corresponding changes in episodic memory and executive functioning in middle and later adulthood. Increases in LPA frequency predicted less decline in episodic memory (ß = 0.06, p = .004) and executive functioning (ß = 0.14, p < .001) over the 9-year follow-up period, even when controlling for moderate and vigorous physical activity. Effect sizes for moderate and vigorous physical activity were less than half that observed for LPA. Moderation models showed that, for episodic memory, the benefits of increases in LPA frequency were more pronounced at older ages. Findings suggest that increases in LPA over extended periods of time may help slow age-related cognitive declines, particularly in later life when opportunities for MVPA are often diminished.

Goal adjustment capacities in uncontrollable life circumstances: Benefits for psychological well-being during COVID-19.

Goal adjustment capacities (i.e., goal disengagement and goal reengagement) are core self-regulatory resources theorized to buffer psychological well-being during intractable life circumstances. However, research has yet to examine whether these capacities protect well-being for individuals who encounter uncontrollable losses in their ability to pursue important life goals due to the COVID-19 pandemic. Using a nationally-representative sample of U.S. adults aged 18-80 (n = 292), the present longitudinal study examined the extent to which goal disengagement and reengagement predicted levels and change in psychological well-being for individuals who differed in perceived control over their goals early in the pandemic. Results from multilevel growth models showed that goal reengagement, but not goal disengagement, capacities predicted higher levels of well-being during the pandemic (lower perceived stress, depressive symptoms; higher life satisfaction, meaning in life). Moderation models showed the benefits of goal reengagement for well-being were pronounced among individuals who perceived pandemic-induced declines in control over their goals. Findings inform theories of motivation and self-regulation and point to the adaptive value of goal reengagement capacities during uncontrollable life circumstances.

Conscientiousness and Cardiometabolic Risk: A Test of the Health Behavior Model of Personality Using Structural Equation Modeling.

BACKGROUND: High trait conscientiousness is associated with lower cardiometabolic risk, and health behaviors are a putative but relatively untested pathway that may explain this association. PURPOSE: To explore the role of key health behaviors (diet, physical activity, substance use, and sleep) as links between conscientiousness and cardiometabolic risk. METHODS: In a cross-sectional analysis of 494 healthy, middle-aged working adults (mean age = 42.7 years, 52.6% women, 81.0% White), participants provided self-reports of conscientiousness, physical activity, substance use, diet, and sleep, and wore monitors over a 7-day monitoring period to assess sleep (Actiwatch-16) and physical activity (SenseWear Pro3). Cardiometabolic risk was expressed as a second-order latent variable from a confirmatory factor analysis involving insulin resistance, dyslipidemia, obesity, and blood pressure. Direct, indirect, and specific indirect effect pathways linking conscientiousness to health behaviors and cardiometabolic risk were examined. Unstandardized indirect effects for each health behavior class were computed separately using bootstrapped samples. RESULTS: After controlling for demographics (sex, age, race, and education), conscientiousness showed the predicted, inverse association with cardiometabolic risk. Among the examined health behaviors, objectively-assessed sleep midpoint variability (b = -0.003, p = .04), subjective sleep quality (b = -0.003, p = .025), and objectively-assessed physical activity (b = -0.11, p = .04) linked conscientiousness to cardiometabolic risk. CONCLUSIONS: Physical activity and sleep partially accounted for the relationship between conscientiousness and cardiometabolic risk.

Pathways connecting family socioeconomic status in adolescence and sleep continuity in adult Black and White men.

OBJECTIVE: To evaluate the roles of parenting and adolescent characteristics during ages 13 to 16 in connecting family socioeconomic status (SES) during adolescence with adult sleep in Black and White men. DESIGN: Longitudinal school-based community study beginning in 1987-1988 when participants were enrolled in the first or seventh grade. SETTING: Pittsburgh, PA. PARTICIPANTS: 291 men (54.4% Black, mean age = 33, SD = 2.5) participated in 2012-2014 in a week-long study of sleep measured by actigraphy and diary. MEASURES: In adolescence (ages 13-16), measures of family SES based on occupation, education, income and public assistance; parenting based on monitoring, positive expectations for future, warm parent-child relationship, and communication; and adolescent characteristics based on anxiety, hyperactivity/impulsivity, and peer rejection.  In adulthood, participant SES, minutes awake after sleep onset (WASO), duration, and diary-assessed sleep quality. RESULTS: Structural equation modeling confirmed significant indirect pathways: (1) low family SES in adolescence to negative parenting to low adult SES to greater WASO; (2) low family SES in adolescence to adolescent characteristics to low adult SES to greater WASO; (3) Black race to low family SES in adolescence to negative parenting to low adult SES to greater WASO; and (4) Black race to low family SES in adolescence to adolescent characteristics to adult SES to greater WASO. Similar models for duration and quality were not confirmed. CONCLUSIONS: Parenting and adolescent characteristics may have an indirect association with adult sleep continuity. Parenting and mental health interventions in adolescence may improve adult sleep.

Prospective Associations of Parenting and Childhood Maltreatment with Personality in Adolescent Males.

This longitudinal study examines whether early experiences with caregivers between the ages of 10 and 12 are associated with later adolescent personality at age 16 using both parent and child reports. Lower positive parenting was prospectively associated with higher neuroticism and lower extraversion and conscientiousness for both parent and self-reports of personality, as well as lower openness and agreeableness by parent report. Substantiated maltreatment was prospectively associated with greater neuroticism and lower agreeableness and conscientiousness assessed by parent report. Prospective associations were similar across Black and White participants. Positive parenting and, to a lesser extent, a lack of maltreatment were associated with adaptive personality profiles in adolescents, and associations were stronger for parent reports of personality.

Big 5 personality traits and intraindividual variability in sleep duration, continuity, and timing.

OBJECTIVES: The personality traits of conscientiousness and neuroticism have been consistently linked to mean-level, self-reported sleep duration and continuity. The present study expands this literature by using actigraphy sleep assessment to examine how personality is related to both mean-level and the intraindividual variability in sleep duration, continuity, and timing. DESIGN: One-week ecological sleep assessment. SETTING: The research was conducted at a mid-size Midwestern university. Actigraphy data were collected at participants' homes. PARTICIPANT: The study had a sample size of 358 college-aged participants. MEASUREMENTS: Sleep duration, continuity, and timing were assessed for 7 consecutive nights using actigraphy. Participants also completed a self-report assessment of personality. RESULTS: Conscientiousness and extraversion emerged as the key personality predictors of sleep outcomes. Higher conscientiousness was associated with longer average sleep duration and earlier timing, as well as higher consistency in total sleep time. Higher extraversion was associated with later bedtimes, less total sleep time, and more variability in their sleep timing. Neuroticism, agreeableness, and openness to experience were not significantly related to sleep. CONCLUSION: The study's results highlight the importance of personality in sleep research, with implications for sleep health promotion efforts.

Prospective associations among objectively and subjectively assessed sleep and the metabolic syndrome.

OBJECTIVE: Subjective sleep disturbances have been associated with greater risk for concurrent and incident metabolic syndrome (MetS). Previous studies have not examined prospective associations among polysomnography-assessed sleep and the MetS, despite knowledge that self-reported sleep is subject to reporting bias, and that subjectively and objectively assessed sleep are weakly correlated. METHOD: In the current study, objectively-assessed (polysomnography) and subjectively-assessed (Pittsburgh Sleep Quality Index, PSQI) sleep was measured in 145 adults at two timepoints, separated by 12-30 years. A continuous measure of the MetS was assessed at the second time point. Statistical analyses were adjusted for age, sex, lifetime history of major depressive disorder, follow-up time, and apnea-hypopnea index. RESULTS: Polysomnography-assessed sleep duration, latency, efficiency, and slow wave sleep were not significantly prospectively associated with the MetS (ps ≥ 0.16). Self-reported longer sleep latency was prospectively associated with higher MetS scores in unadjusted (ß = 0.29, p = 0.002) and adjusted models (ß = 0.25, p = 0.009). Longer sleep latency was associated with higher fasting glucose levels (ß = 0.47, p < 0.001). CONCLUSION: Our study provides evidence that subjective and objective measures of sleep may differ in their ability to prospectively predict MetS.

Prospective Associations of Adolescent Conscientiousness With Psychological Resources and Metabolic Syndrome in Black and White Men.

OBJECTIVE: Conscientiousness predicts better psychological resources as well as lower cardiovascular mortality and lower metabolic syndrome (MetS) risk. However, the benefits of conscientiousness might be amplified, disabled, or reversed in disadvantaged groups. This study is the first to test these competing hypotheses for prospective associations between adolescent conscientiousness and adult psychological resources and MetS. METHOD: Participants were 220 men (54.6% black) from the Pittsburgh Youth Study. Adolescent conscientiousness (M [SD] age = 16 [1]) was rated by participants and their parents. Adult (M [SD] age = 32 [1]) socioeconomic status (SES; occupation and education), psychological resources (composite of positive affect, purpose in life, optimism, self-mastery, and self-esteem), and MetS scores (glucose, lipids, waist circumference, and blood pressure) were measured. Hierarchical regressions were used to evaluate the association of conscientiousness with adult psychological resources and MetS scores, with testing of moderation by race and SES. RESULTS: Self- and parent-reported conscientiousness were associated with better psychological resources (ßs = 0.23-0.29, ps ≤ .015), with no moderation by race or socioeconomic status. In the full sample, a three-way interaction of self-reported conscientiousness, race, and SES was obtained for MetS (ß = 0.12, p = .093). Subgroup analysis indicated that self-reported conscientiousness was related to higher MetS scores in low SES black men (ßint = -0.22, p = .022), but there was no comparable linear (ßs ≤ 0.08, ps ≥ .50) or interaction (ßs ≤ -0.13 ps ≥ .25) pattern in white men. CONCLUSIONS: Adolescent conscientiousness was beneficial for adult psychological resources, regardless of race or SES. However, there may be physiological costs of conscientiousness for black men from disadvantaged backgrounds.

The impact of frequent napping and nap practice on sleep-dependent memory in humans.

Napping benefits long-term memory formation and is a tool many individuals use to improve daytime functioning. Despite its potential advantages, approximately 47% of people in the United States eschew napping. The goal of this study was to determine whether people who endorse napping at least once a week (nap+) show differences in nap outcomes, including nap-dependent memory consolidation, compared with people who rarely or never nap (nap-). Additionally, we tested whether four weeks of nap practice or restriction would change sleep and performance profiles. Using a perceptual learning task, we found that napping enhanced performance to a greater degree in nap+ compared with nap- individuals (at baseline). Additionally, performance change was associated with different electrophysiological sleep features in each group. In the nap+ group, spindle density was positively correlated with performance improvement, an effect specific to spindles in the hemisphere contralateral to the trained visual field. In the nap- group, slow oscillatory power (0.5-1 Hz) was correlated with performance. Surprisingly, no changes to performance or brain activity during sleep emerged after four weeks of nap practice or restriction. These results suggest that individual differences may impact the potential benefits of napping on performance and the ability to become a better napper.

Cardiovascular Stress Reactivity and Carotid Intima-Media Thickness: The Buffering Role of Slow-Wave Sleep.

OBJECTIVE: Exaggerated cardiovascular reactivity to acute psychological stress has been associated with increased carotid intima-media thickness (IMT). However, interstudy variability in this relationship suggests the presence of moderating factors. The current study aimed to test the hypothesis that poor nocturnal sleep, defined as short total sleep time or low slow-wave sleep, would moderate the relationship between cardiovascular reactivity and IMT. METHODS: Participants (N = 99, 65.7% female, age = 59.3 ± 9.3 years) completed a two-night laboratory sleep study and cardiovascular examination where sleep and IMT were measured. The multisource interference task was used to induce acute psychological stress, while systolic and diastolic blood pressure and heart rate were monitored. Moderation was tested using the PROCESS framework in SPSS. RESULTS: Slow-wave sleep significantly moderated the relationship between all cardiovascular stress reactivity variables and IMT (all pinteraction ≤ .048, all ΔRinteraction ≥ .027). Greater stress reactivity was associated with higher IMT values in the low slow-wave sleep group and lower IMT values in the high slow-wave sleep group. No moderating effects of total sleep time were observed. CONCLUSIONS: The results provide evidence that nocturnal slow-wave sleep moderates the relationship between cardiovascular stress reactivity and IMT and may buffer the effect of daytime stress-related disease processes.

To Nap, Perchance to DREAM: A Factor Analysis of College Students' Self-Reported Reasons for Napping.

Although napping has received attention because of its associations with health and use as a method to understand the function of sleep, to our knowledge no study has systematically and statistically assessed reasons for napping. Using factor analysis, we determined the underlying structure of reasons for napping in diverse undergraduates (N = 430, 59% female) and examined their relationships with self-reported sleep, psychological health, and physical health. The five reasons for napping can be summarized using the acronym DREAM (Dysregulative, Restorative, Emotional, Appetitive, and Mindful). Only Emotional reasons for napping were uniformly related to lower well-being. The use of factor analysis raises possibilities for future research, including examining the stability, structure, and psychological and physical health processes related to napping throughout the lifespan.

Animation Stimuli System for Research on Instructor Gestures in Education.

Education research has shown that instructor gestures can help capture, maintain, and direct the student's attention during a lecture as well as enhance learning and retention. Traditional education research on instructor gestures relies on video stimuli, which are time consuming to produce, especially when gesture precision and consistency across conditions are strictly enforced. The proposed system allows users to efficiently create accurate and effective stimuli for complex studies on gesture, without the need for computer animation expertise or artist talent.

Perceived sleep quality: The interplay of neuroticism, affect, and hyperarousal.

INTRODUCTION: Many adults experience poor sleep quality, and personality traits have emerged as important predictors of self-reported sleep. However, it is still unclear whether personality predicts sleep quality independent of other correlates, including mood, emotion regulation, and hyperarousal. AIMS AND METHOD: The aim of this study was twofold. First, using an online survey, we assessed the relationship between perceived sleep quality (defined here as the total score of the Pittsburgh Sleep Quality Index) and personality in 498 Italians (M age=26.6±7.4 years, 353 Female). Second, using multiple regressions, we investigated whether this association was independent of affect, emotion regulation strategies, and hyperarousal. RESULTS: Results replicate previous findings, showing that neuroticism is the best personality predictor of sleep quality in Italians. When examined separately, hyperarousal explained the most variance in sleep quality (R2=.18), followed by personality traits (R2=.12), affect (R2=.12), and emotion regulation strategies (R2=.01). However, when all predictors were entered into a single regression model (R2=.20), only agreeableness, positive affect, and hyperarousal remained statistically significant. CONCLUSION: Overall, our data replicate the association between personality and perceived sleep quality in Italians, showing that neuroticism is the best predictor of worse sleep quality. Finally, we also demonstrate important roles for hyperarousal and positive affect, but not for emotion regulation strategies. Results have implications for applied research and interventions that may want to identify individuals at risk for poor sleep.

Hand Gesture and Mathematics Learning: Lessons From an Avatar.

A beneficial effect of gesture on learning has been demonstrated in multiple domains, including mathematics, science, and foreign language vocabulary. However, because gesture is known to co-vary with other non-verbal behaviors, including eye gaze and prosody along with face, lip, and body movements, it is possible the beneficial effect of gesture is instead attributable to these other behaviors. We used a computer-generated animated pedagogical agent to control both verbal and non-verbal behavior. Children viewed lessons on mathematical equivalence in which an avatar either gestured or did not gesture, while eye gaze, head position, and lip movements remained identical across gesture conditions. Children who observed the gesturing avatar learned more, and they solved problems more quickly. Moreover, those children who learned were more likely to transfer and generalize their knowledge. These findings provide converging evidence that gesture facilitates math learning, and they reveal the potential for using technology to study non-verbal behavior in controlled experiments.

Autonomic activity during sleep predicts memory consolidation in humans.

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.

Automatic detection of rapid eye movements (REMs): A machine learning approach.

BACKGROUND: Rapid eye movements (REMs) are a defining feature of REM sleep. The number of discrete REMs over time, or REM density, has been investigated as a marker of clinical psychopathology and memory consolidation. However, human detection of REMs is a time-consuming and subjective process. Therefore, reliable, automated REM detection software is a valuable research tool. NEW METHOD: We developed an automatic REM detection algorithm combining a novel set of extracted features and the 'AdaBoost' classification algorithm to detect the presence of REMs in Electrooculogram data collected from the right and left outer canthi (ROC/LOC). Algorithm performance measures of Recall (percentage of REMs detected) and Precision (percentage of REMs detected that are true REMs) were calculated and compared to the gold standard of human detection by three expert sleep scorers. REM detection by four non-experts were also investigated and compared to expert raters and the algorithm. RESULTS: The algorithm performance (78.1% Recall, 82.6% Precision) surpassed that of the average (expert & non-expert) single human detection performance (76% Recall, 83% Precision). Agreement between non-experts (Cronbach Alpha=0.65) is markedly lower than experts (Cronbach Alpha=0.80). COMPARISON WITH EXISTING METHOD(S): By following reported methods, we implemented all previously published LOC and ROC based detection algorithms on our dataset. Our algorithm performance exceeded all others. CONCLUSIONS: The automatic detection algorithm presented is a viable and efficient method of REM detection as it reliably matches the performance of human scorers and outperforms all other known LOC- and ROC-based detection algorithms.

REM sleep rescues learning from interference.

Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost.

Childhood sleep duration and lifelong mortality risk.

OBJECTIVE: Sleep duration is known to significantly affect health in adults and children, but little is understood about long-term associations. This prospective cohort study is the first to examine whether childhood sleep duration is associated with lifelong mortality risk. METHOD: Data from childhood were refined and mortality data collected for 1,145 participants from the Terman Life Cycle Study. Participants were born between 1904 and 1915, lived to at least 1940, and had complete age, bedtime, and waketime data at initial data collection (1917-1926). Homogeneity of the cohort sample (intelligent, mostly White) limits generality but provides natural control of common confounds. Through 2009, 1,039 participants had confirmed deaths. Sleep duration was calculated as the difference between each child's bed and wake times. Age-adjusted sleep (deviation from that predicted by age) was computed. Cox proportional hazards survival models evaluated childhood sleep duration as a predictor of mortality separately by sex, controlling for baseline age. RESULTS: For males, a quadratic relation emerged: Male children who underslept or overslept compared with peers were at increased risk of lifelong all-cause mortality (HR = 1.15, CIs [1.05, 1.27]). Effect sizes were smaller and nonsignificant in females (HR = 1.02, CIs [0.91, 1.14]). CONCLUSIONS: Male children with shorter or longer sleep durations than expected for their age were at increased risk of death at any given age in adulthood. The findings suggest that sleep may be a core biobehavioral trait, with implications for new models of sleep and health throughout the entire life span.

Personality and healthy sleep: the importance of conscientiousness and neuroticism.

Although previous research has shown personality and sleep are each substantial predictors of health throughout the lifespan, little is known about links between personality and healthy sleep patterns. This study examined Big Five personality traits and a range of factors related to sleep health in 436 university students (M(age) = 19.88, SD = 1.50, 50% Male). Valid self-report measures of personality, chronotype, sleep hygiene, sleep quality, and sleepiness were analyzed. To remove multicollinearity between personality factors, each sleep domain was regressed on relevant demographic and principal component-derived personality factors in multiple linear regressions. Results showed that low conscientiousness and high neuroticism were the best predictors of poor sleep (poor sleep hygiene, low sleep quality, and increased sleepiness), consistent with other research on predictors of poor health and mortality risk. In this first comprehensive study of the topic, the findings suggest that personality has a significant association with sleep health, and researchers could profitably examine both personality and sleep in models of health and well-being.

The benefit of offline sleep and wake for novel object recognition.

How do we segment and recognize novel objects? When explicit cues from motion and color are available, object boundary detection is relatively easy. However, under conditions of deep camouflage, in which objects share the same image cues as their background, the visual system must reassign new functional roles to existing image statistics in order to group continuities for detection and segmentation of object boundaries. This bootstrapped learning process is stimulus dependent and requires extensive task-specific training. Using a between-subject design, we tested participants on their ability to segment and recognize novel objects after a consolidation period of sleep or wake. We found a specific role for rapid eye movement (REM, n = 43) sleep in context-invariant novel object learning, and that REM sleep as well as a period of active wake (AW, n = 35) increased segmentation of context-specific object learning compared to a period of quiet wake (QW, n = 38; p = .007 and p = .017, respectively). Performance in the non-REM nap group (n = 32) was not different from the other groups. The REM sleep enhancement effect was especially robust for the top performing quartile of subjects, or "super learners" (p = .037). Together, these results suggest that the construction and generalization of novel representations through bootstrapped learning may benefit from REM sleep, and more specific object learning may also benefit from AW. We discuss these results in the context of shared electrophysiological and neurochemical features of AW and REM sleep, which are distinct from QW and non-REM sleep.