Objective and Subjective Intraindividual Variability in Sleep: Predisposing Factors and Health Consequences.

OBJECTIVE: We investigated the factors that predispose or precipitate greater intraindividual variability (IIV) in sleep. We further examined the potential consequences of IIV on overall sleep quality and health outcomes, including whether these relationships were found in both self-reported and actigraphy-measured sleep IIV. METHODS: In Study 1, 699 US adults completed a Sleep Intra-Individual Variability Questionnaire and self-reported psychosocial, sleep quality, and health outcomes. In Study 2, 100 university students wore actigraphy and completed psychosocial, sleep, and health surveys at multiple timepoints. RESULTS: In cross-sectional analyses that controlled for mean sleep duration, predisposing/precipitating factors to greater IIV were being an underrepresented racial/ethnic minority (Study 1: F = 13.95, p < .001; Study 2: F = 7.03, p = .009), having greater stress (Study 2: r values ≥ 0.32, p values ≤ .002) or trait vulnerability to stress (Study 1: r values ≥ 0.15, p values < .001), and showing poorer time management (Study 1: r values ≤ -0.12, p values ≤ .004; Study 2: r values ≤ -0.23, p values ≤ .028). In addition, both studies showed that greater sleep IIV was associated with decreased overall sleep quality, independent of mean sleep duration (Study 1: r values ≥ 0.20, p values < .001; Study 2: r values ≥ 0.33, p values ≤ .001). Concordance across subjective and objective IIV measures was modest ( r values = 0.09-0.35) and similar to concordance observed for subjective-objective mean sleep duration measures. CONCLUSION: Risk for irregular sleep patterns is increased in specific demographic groups and may be precipitated by, or contribute to, higher stress and time management inefficiencies. Irregular sleep may lead to poor sleep quality and adverse health outcomes, independent of mean sleep duration, underscoring the importance of addressing sleep consistency.

Digital Methods for Performing Daily Tasks Among Older Adults: An Initial Report of Frequency of Use and Perceived Utility.

OBJECTIVE: Digital technologies permit new ways of performing instrumental activities of daily living (iADLs) for older adults, but these approaches are not usually considered in existing iADL measures. The current study investigated how a sample of older adults report using digital versus analog approaches for iADLs. METHOD: 248 older adults completed the Digital and Analog Daily Activities Survey, a newly developed measure of how an individual performs financial, navigation, medication, and other iADLs. RESULTS: The majority of participants reported regularly using digital methods for some iADLs, such as paying bills (67.7%) and using GPS (67.7%). Low digital adopters were older than high adopters (F(2, 245) = 12.24, p < .001), but otherwise the groups did not differ in terms of gender, years of education, or history of neurological disorders. Participants who used digital methods relatively more than analog methods reported greater levels of satisfaction with their approach and fewer daily errors. CONCLUSIONS: Many older adults have adopted digital technologies for supporting daily tasks, which suggests limitations to the validity of current iADL assessments. By capitalizing on existing habits and enriching environments with new technologies, there are opportunities to promote technological reserve in older adults in a manner that sustains daily functioning.

Rapid sleep education: If you could tell people one thing about sleep, what should it be?

Informal learning settings such as museums provide unique opportunities for educating a local community about sleep. However, in such settings, information must be capable of immediately inciting interest. We developed a series of sleep "icebreakers" (brief, informal facts) to determine whether they elicited interest in sleep and encouraged behavioural change. There were 859 participants across three cross-sectional samples: (a) members of the local museum; (b) Mechanical Turk workers who responded to a "sleep" study advertisement; and (c) Mechanical Turk workers who responded to a "various topics" study advertisement that did not mention sleep. All three samples demonstrated high interest in sleep topics, though delayed recall of the icebreakers was strongest in participants who expected to learn about the sleep topics. Icebreaker interest ratings were independent of age, gender and race/ethnicity, suggesting that sleep is a topic of universal interest. Importantly, regardless of demographics and sample, the more the icebreakers interested the participants, the more likely participants were to indicate willingness to donate to a sleep exhibit, change their sleep behaviours, and post to social media. Thus, sleep icebreakers can rapidly elicit people's interest, and future outreach efforts should couple icebreakers with opportunities for subsequent personalized learning.

COVID-19-Related News Consumption Linked with Stress and Worry, but Not Sleep Quality, Early in the Pandemic.

Beginning in early 2020, the novel coronavirus was the subject of frequent and sustained news coverage. Building on prior literature on the stress-inducing effects of consuming news during a large-scale crisis, we used network analysis to investigate the association between coronavirus disease 2019 (COVID-19) news consumption, COVID-19-related psychological stress, worries about oneself and one's loved ones getting COVID-19, and sleep quality. Data were collected in March 2020 from 586 adults (45.2% female; 72.9% White) recruited via Amazon Mechanical Turk in the U.S. Participants completed online surveys assessing attitudes and behaviors related to COVID-19 and a questionnaire assessing seven domains of sleep quality. Networks were constructed using partial regularized correlation matrices. As hypothesized, COVID-19 news consumption was positively associated with COVID-19-related psychological stress and concerns about one's loved ones getting COVID-19. However, there were very few associations between COVID-19 news consumption and sleep quality indices, and gender did not moderate any of the observed relationships. This study replicates and extends previous findings that COVID-19-news consumption is linked with psychological stress related to the pandemic, but even under such conditions, sleep quality can be spared due to the pandemic allowing for flexibility in morning work/school schedules.

The Prospective Sleeping Brain: Age-Related Differences in Episodic Future Thinking and Frontal Sleep Spindles.

Sleep spindles are a physiological marker of off-line memory consolidation. In young adults, sleep spindles are preferentially responsive to encoded information that is tagged as having future relevance. Older adults, on the other hand, show reduced capacity for future simulation and alterations in sleep physiology. Healthy young adults (n = 38) and older adults (n = 28) completed an adaptation night, followed by two in-laboratory polysomnography nights, in which they mentally simulated future events or remembered past events, recorded via written descriptions. We quantified the degree of future/past thinking using linguistic analysis of time orientation. In young adults, greater future thinking was linked to greater spindle density, even when controlling for gender, age, and word count (rp = .370, p = .028). The opposite was true for older adults, such that greater future thinking was associated with reduced spindle density (rp = -.431, p = .031). These patterns were selective to future thinking (not observed for past thinking). The collective findings implicate an impaired interaction between future relevance tagging and sleep physiology as a mechanism by which aging compromises sleep-dependent cognitive processing.

Bedtime Music, Involuntary Musical Imagery, and Sleep.

Many people listen to music for hours every day, often near bedtime. We investigated whether music listening affects sleep, focusing on a rarely explored mechanism: involuntary musical imagery (earworms). In Study 1 (N = 199, mean age = 35.9 years), individuals who frequently listen to music reported persistent nighttime earworms, which were associated with worse sleep quality. In Study 2 (N = 50, mean age = 21.2 years), we randomly assigned each participant to listen to lyrical or instrumental-only versions of popular songs before bed in a laboratory, discovering that instrumental music increased the incidence of nighttime earworms and worsened polysomnography-measured sleep quality. In both studies, earworms were experienced during awakenings, suggesting that the sleeping brain continues to process musical melodies. Study 3 substantiated this possibility by showing a significant increase in frontal slow oscillation activity, a marker of sleep-dependent memory consolidation. Thus, some types of music can disrupt nighttime sleep by inducing long-lasting earworms that are perpetuated by spontaneous memory-reactivation processes.

Classical music, educational learning, and slow wave sleep: A targeted memory reactivation experiment.

Poor sleep in college students compromises the memory consolidation processes necessary to retain course materials. A solution may lie in targeting reactivation of memories during sleep (TMR). Fifty undergraduate students completed a college-level microeconomics lecture (mathematics-based) while listening to distinctive classical music (Chopin, Beethoven, and Vivaldi). After they fell asleep, we re-played the classical music songs (TMR) or a control noise during slow wave sleep. Relative to the control condition, the TMR condition showed an 18% improvement for knowledge transfer items that measured concept integration (d = 0.63), increasing the probability of "passing" the test with a grade of 70 or above (OR = 4.68, 95%CI: 1.21, 18.04). The benefits of TMR did not extend to a 9-month follow-up test when performance dropped to floor levels, demonstrating that long-term-forgetting curves are largely resistant to experimentally-consolidated memories. Spectral analyses revealed greater frontal theta activity during slow wave sleep in the TMR condition than the control condition (d = 0.87), and greater frontal theta activity across conditions was associated with protection against long-term-forgetting at the next-day and 9-month follow-up tests (rs = 0.42), at least in female students. Thus, students can leverage instrumental music-which they already commonly pair with studying-to help prepare for academic tests, an approach that may promote course success and persistence.

The smartphone in the memory clinic: A study of patient and care partner's utilisation habits.

Smartphones have potential as cognitive aids for adults with cognitive impairments. However, little is known about how patients and their care partners utilise smartphones in their day-to-day lives. We collected self-reported smartphone utilisation data from patients referred for neuropsychological evaluations (N = 53), their care partners (N = 44), and an Amazon Mechanical Turk control sample (N = 204). Patient participants were less likely to own a smartphone than controls, with increasing age associated with less utilisation of smartphone features in all groups. Of the patients who owned smartphones, spontaneous use of cognitive aid features (e.g., reminders and calendars) occurred on only a monthly-to-weekly basis; by comparison, patients reported utilising social/general features (e.g., email and internet) on a weekly-to-daily basis. Individuals referred for geriatric cognitive disorder evaluations were less likely to own and use smartphones than individuals referred for other reasons. Care partners reported using their smartphones more frequently than control group adults, with 55% of care partners endorsing utilising their device in caring for the patient. Building upon existing smartphone use habits to increase the use of cognitive aid features may be a feasible intervention for some patients, and including care partners in such interventions is encouraged.

Implications for technological reserve development in advancing age, cognitive impairment, and dementia.

This commentary draws connections between technological culture emergence and recent trends in using assistive technology to reduce the burden of Alzheimer's disease. By the technical-reasoning hypothesis, cognitively-impaired individuals will lack the cognitive ability to employ technologies. By the technological reserve hypothesis, social-motivational and cultural transmissibility factors can provide foundations for using technology as cognitive prosthetics even during neurodegenerative illnesses.

The Cognitive Attentional Syndrome is Associated With Sleep Difficulties in a Community Sample.

We examined whether a process common to anxiety, labeled the cognitive attentional syndrome (CAS), is also associated with sleep disturbances. The CAS represents the sustained use of self-regulating strategies, such as rumination and worry, and beliefs individuals hold about such strategies. Using a sample of community adults located in the United States (N = 226), we found that the CAS was positively associated with sleep difficulties. The association remained intact after controlling for demographic variables, physical health, and negative affect. We further found that self-regulating strategies may be the component of the CAS that is most important to sleep disturbances. Future experimental studies are needed to elucidate whether there exists a causal, and potentially bidirectional, link between the CAS and sleep difficulties.

An implementation intention strategy can improve prospective memory in older adults with very mild Alzheimer's disease.

OBJECTIVES: This study tested whether (1) very mild Alzheimer's disease (AD) is associated with impaired prospective memory (PM) for tasks that are supported by either spontaneous retrieval (focal PM) or strategic monitoring (non-focal PM) and (2) implementation intention (II) encoding could improve PM performance in very mild AD. DESIGN: Thirty-eight healthy older adults and 34 with very mild AD were randomly assigned to perform two PM tasks in either the standard or the II encoding condition. METHOD: All participants performed blocks of category decision in which they were asked to respond to a focal PM target (e.g., the word 'orange') and a non-focal PM target (e.g., words that begin with the letter 'o'). Half of the participants encoded PM instructions in the standard manner, while the other half had a stronger encoding by forming IIs. PM accuracy and category decision accuracy and reaction times were measured. RESULTS: Participants with very mild AD showed deficits in both focal and non-focal PM performance compared to the healthy controls, reflecting deficits in both spontaneous retrieval and strategic monitoring. Participants with very mild AD in the II encoding condition showed better focal PM performance relative to those in the standard encoding condition. CONCLUSIONS: Deficits in both focal and non-focal PM are associated with very mild AD and IIs may be a helpful behavioural intervention for the focal PM deficits. PRACTITIONER POINTS: Multiple deficits in PM are observable in very mild AD. Implementation intentions may enhance focal PM in very mild AD. Future research using larger samples is needed to better understand the effect of II on non-focal PM tasks in healthy older adults and those with very mild AD. The use of simple laboratory PM tasks may limit the generality of our findings. Future research is needed to investigate whether IIs improve PM over a range of more realistic tasks.

Fluctuations in cognition and alertness vary independently in dementia with Lewy bodies.

Fluctuations in mental status are 1 of the core diagnostic criteria for dementia with Lewy bodies (DLB) and are thought to reflect variability in daytime alertness. Previous attempts to study fluctuations have been limited to caregiver reports, observer rating scales, short segments of electroencephalography, or motor-dependent, reaction time tests. Concordance among such measures is often poor, and fluctuations remain difficult to quantify. We compared fluctuations in cognition and alertness in patients with DLB (n = 13) and idiopathic Parkinson's disease (PD) (n = 64), a condition associated with deficits in daytime alertness. We systematically and repeatedly collected cognitive and physiologic measures during a 48-hour inpatient protocol in a sound-attenuated sleep laboratory in a geriatric hospital. Cognitive fluctuations were analyzed using coefficients of variation (COVs) derived from performance on a bedside examination familiar to clinicians (digit span). Alertness fluctuations were assessed objectively using COVs from the polysomnographically-based Maintenance of Wakefulness Test. Despite predictably lower mean digit span performances, DLB patients demonstrated significantly greater cognitive fluctuations than PD patients (P < 0.001), even when groups were matched on general cognitive impairment. There were no group differences in alertness fluctuations, although DLB patients were less alert than PD patients not receiving dopaminergics. The prevailing assumption that fluctuations in cognition in DLB are reflected in fluctuations in daytime alertness was not supported by objective, physiological measurements. Fluctuating mental status in DLB patients can be detected with repeated administration of a simple bedside exam that can be adapted to a clinic setting.

Medical malpractice litigation and daylight saving time.

STUDY OBJECTIVES: Daylight saving time (DST) constitutes a natural quasi-experiment to examine the influence of mild sleep loss and circadian misalignment. We investigated the acute effects of spring transition into DST and the chronic effects of DST (compared to standard time) on medical malpractice claims in the United States over 3 decades. METHODS: We analyzed 288,432 malpractice claims from the National Practitioner Data Bank. To investigate the acute effects of spring DST transition, we compared medical malpractice incidents/decisions 1 week before spring DST transition, 1 week following spring DST transition, and the rest of the year. To investigate the chronic effects of DST months, we compared medical malpractice incidents/decisions averaged across the 7-8 months of DST vs the 4-5 months of standard time. RESULTS: With regard to acute effects, spring DST transitions were significantly associated with higher payment decisions but not associated with the severity of medical incidents. With regard to chronic effects, the 7-8 DST months were associated with higher average payments and worse severity of incidents than the 4-5 standard time months. CONCLUSIONS: The mild sleep loss and circadian misalignment associated with DST may influence the incidence of medical errors and decisions on medical malpractice payments both acutely and chronically. CITATION: Gao C, Lage C, Scullin MK. Medical malpractice litigation and daylight saving time. J Clin Sleep Med. 2024;20(6):933-940.

Internet-Enabled Behaviors in Older Adults During the Pandemic: Patterns of Use, Psychosocial Impacts, and Plans for Continued Utilization.

In response to social distancing measures during the COVID-19 pandemic, there was a need to increase the frequency of internet enabled behaviors (IEBs). To date, little is known about how the pandemic impacted IEBs in older adults, a population that has historically been linked to lower digital literacy and utilization. We administered an online survey between April and July 2021 to 298 adults who were over age 50 (mean age = 73 years; 93.5% non-Hispanic white; 94% smart phone owners; 83.5% retired). Older adults self-reported IEBs for social, shopping, medical, and leisure activities during the pandemic, plans for continued use of these behaviors, and completed measures of psychosocial functioning. 66.8% of respondents reported an overall increase in IEBs during the pandemic, most notably for online meeting attendance. More frequent online meeting use was associated with less depression (r = -0.12, p = .04) and less loneliness (r = -0.14, p = .02). With regard to plans for continued use, 82.5% of the sample reported at least one IEB (M = 2.18, SD = 1.65) that they increased during the pandemic and planned to maintain over time (e.g., online shopping for household goods). Plans for continued use were more likely in participants who used IEBs more overall during the pandemic (r = 0.56, p < .001), and who frequently sought technical support on search engines (r = 0.22, p < .001), or online video sites (r = 0.16, p = .006). In summary, IEBs during the pandemic were associated with favorable psychosocial functioning and expectations for continued use in this sample of predominantly white older adults who had some baseline technological familiarity.

Evidence for a detrimental relationship between hypertension history, prospective memory, and prefrontal cortex white matter in cognitively normal older adults.

Hypertension affects many older adults and is associated with impaired neural and cognitive functioning. We investigated whether a history of hypertension was associated with impairments to prospective memory, which refers to the ability to remember to perform delayed intentions, such as remembering to take medication. Thirty-two cognitively normal older adult participants with or without a history of hypertension (self-reported) performed two laboratory prospective memory tasks, one that relied more strongly on executive control (nonfocal prospective memory) and one that relied more strongly on spontaneous memory retrieval processes (focal prospective memory). We observed hypertension-related impairments for nonfocal, but not focal, prospective memory. To complement our behavioral approach, we conducted a retrospective analysis of available structural magnetic resonance imaging data. Lower white matter volume estimates in the anterior prefrontal cortex were associated with lower nonfocal prospective memory and with a history of hypertension. A history of hypertension may be associated with worsened executive control and lower prefrontal white matter volume. The translational implication is that individuals who must remember to take antihypertensive medications and to monitor their blood pressure at home may be impaired in the executive control process that helps to support these prospective memory behaviors.

Controlling intentions: the surprising ease of stopping after going relative to stopping after never having gone.

Decades of cognitive-control research have highlighted the difficulty of controlling a prepotent response. We examined whether having prepotent prospective-memory intentions similarly heightens the difficulty associated with stopping an intention once a prospective-memory task is finished. In three experiments, participants encoded a prospective-memory intention (e.g., press Q in response to the targets corn and dancer) and subsequently encountered either four targets or zero targets. Instructions then indicated that the prospective-memory task was finished. In a follow-up task, the targets appeared, and commission errors were recorded. Surprisingly, it was easier for participants to stop the intention when it had been fulfilled (four-target condition) than when it had gone unfulfilled (zero-target condition; Experiments 1 and 2). This was true even after intention cancellation (Experiment 2). Although repeatedly performing an intention strengthens target-action links, it appears to enable deactivation of the intention, a process that is largely target specific (Experiment 3). We relate these findings to the Zeigarnik effect, target-action deactivation, and reconsolidation theories.

Dissociable neural routes to successful prospective memory.

Identifying the processes by which people remember to execute an intention at an appropriate moment (prospective memory) remains a fundamental theoretical challenge. According to one account, top-down attentional control is required to maintain activation of the intention, initiate intention retrieval, or support monitoring. A diverging account suggests that bottom-up, spontaneous retrieval can be triggered by cues that have been associated with the intention and that sustained attentional processes are not required. We used a specialized experimental design and functional MRI methods to selectively marshal and identify each process. Results revealed a clear dissociation. One prospective-memory task recruited sustained activity in attentional-control areas, such as the anterior prefrontal cortex; the other engaged purely transient activity in parietal and ventral brain regions associated with attentional capture, target detection, and episodic retrieval. These patterns provide critical evidence that there are two neural routes to prospective memory, with each route emerging under different circumstances.

The Dynamic Multiprocess Framework: evidence from prospective memory with contextual variability.

The ability to remember to execute delayed intentions is referred to as prospective memory. Previous theoretical and empirical work has focused on isolating whether a particular prospective memory task is supported either by effortful monitoring processes or by cue-driven spontaneous processes. In the present work, we advance the Dynamic Multiprocess Framework, which contends that both monitoring and spontaneous retrieval may be utilized dynamically to support prospective remembering. To capture the dynamic interplay between monitoring and spontaneous retrieval, we had participants perform many ongoing tasks and told them that their prospective memory cue may occur in any context. Following either a 20-min or a 12-h retention interval, the prospective memory cues were presented infrequently across three separate ongoing tasks. The monitoring patterns (measured as ongoing task cost relative to a between-subjects control condition) were consistent and robust across the three contexts. There was no evidence for monitoring prior to the initial prospective memory cue; however, individuals who successfully spontaneously retrieved the prospective memory intention, thereby realizing that prospective memory cues could be expected within that context, subsequently monitored. These data support the Dynamic Multiprocess Framework, which contends that individuals will engage monitoring when prospective memory cues are expected, disengage monitoring when cues are not expected, and that when monitoring is disengaged, a probabilistic spontaneous retrieval mechanism can support prospective remembering.

Nocturnal sleep enhances working memory training in Parkinson's disease but not Lewy body dementia.

Working memory is essential to higher order cognition (e.g. fluid intelligence) and to performance of daily activities. Though working memory capacity was traditionally thought to be inflexible, recent studies report that working memory capacity can be trained and that offline processes occurring during sleep may facilitate improvements in working memory performance. We utilized a 48-h in-laboratory protocol consisting of repeated digit span forward (short-term attention measure) and digit span backward (working memory measure) tests and overnight polysomnography to investigate the specific sleep-dependent processes that may facilitate working memory performance improvements in the synucleinopathies. We found that digit span backward performance improved following a nocturnal sleep interval in patients with Parkinson's disease on dopaminergic medication, but not in those not taking dopaminergic medication and not in patients with dementia with Lewy bodies. Furthermore, the improvements in patients with Parkinson's disease on dopaminergic medication were positively correlated with the amount of slow-wave sleep that patients obtained between training sessions and negatively correlated with severity of nocturnal oxygen desaturation. The translational implication is that working memory capacity is potentially modifiable in patients with Parkinson's disease but that sleep disturbances may first need to be corrected.

Resource depletion does not influence prospective memory in college students.

This paper reports an experiment designed to investigate the potential influence of prior acts of self-control on subsequent prospective memory performance. College undergraduates (n=146) performed either a cognitively depleting initial task (e.g., mostly incongruent Stroop task) or a less resource-consuming version of that task (e.g., all congruent Stroop task). Subsequently, participants completed a prospective memory task that required attentionally demanding monitoring processes. The results demonstrated that prior acts of self-control do not impair the ability to execute a future intention in college-aged adults. We conceptually replicated these results in three additional depletion and prospective memory experiments. This research extends a growing number of studies demonstrating the boundary conditions of the resource depletion effect in cognitive tasks.