Depression and sleep quality in older adults: a meta-analysis

The literature emphasizes depression and poor sleep quality as problems that affect many elderly individuals. However, these problems have been related in few studies and there is no meta-analysis performed so far on this relationship. The present research reviewed the studies performed on the subjective sleep quality in order to understand how it relates to depression in older adults. The review was conducted in January 2016 and comprised publications between 2005 and 2015. Based on the electronic databases Web of Science and EBSCO, we used the keywords ‘sleep quality’, ‘depression’, and ‘older’ to identify the empirical studies performed. After assessing the collected studies, we selected those that presented the elderly as participants, resulting in nine papers (N = 3069). A random-effects method was used to evaluate the relationship between depression and sleep. We found that an older person’s lack of good sleep quality is significantly related with depression. The main limitation of this study was the difficulty in collecting a greater number of studies. Future research should consider the importance of additional variables (e.g. moderators) in order to understand and investigate viable interventions for prevention and health promotion in the elderly.     

Daily stress interacts with trait dissociation to predict sleep-related experiences in young adults

Building on the previously documented effects of stress and dissociation on sleep and dreaming, we examined their interactive role in general sleep-related experiences (GSEs; e.g., nightmares, falling dreams, hypnagogic hallucinations; see Watson, 2001). Stress, sleep quality, and GSEs were assessed daily for 14 days among young adults. Baseline assessment included life stress, sleep quality, psychopathology, dissociation, and related dimensions. Multilevel analyses indicated that daily stress brings about GSEs among highly dissociative young adults. Additionally, baseline trait dissociation predicted within-subject elevation in GSEs when daily stress was high. Flawed sleep-wake transitions, previously linked to dissociation and sleep-related experiences, might account for this effect.     

Effects of sleep deprivation on performance and EEG spectral analysis in young adults

Nine totally sleep deprived (TSD) and nine control subjects were evaluated with a complete battery for attention and memory performance. Frontal and temporal EEGs (5 min, eyes closed) were also recorded before and after the night. TSD subjects exhibited three performance deficits: learning the Pursuit Rotor Task, implicit recall of paired words, and distractibility on the Brown-Peterson Test. Relative to evening recordings, control subjects showed decreased morning absolute powers in all electrodes for all frequencies except for Frontal delta; TSD subjects showed increased Frontal and Temporal theta and Frontal beta. These results show that motor procedural, implicit memory, and working memory are sensitive to one night of TSD, and that Frontal and Temporal theta spectral power seem to discriminate between a night with sleep from a night without.     

Hemispheric lateralization of the EEG during wakefulness and REM sleep in young healthy adults

EEG recordings confirm hemispheric lateralization of brain activity during cognitive tasks. The aim of the present study was to investigate spontaneous EEG lateralization under two conditions, waking and REM sleep. Bilateral monopolar EEG was recorded in eight participants using a 12-electrode montage, before the night (5 min eyes closed) and during REM sleep. Spectral analysis (0.75-19.75 Hz) revealed left prefrontal lateralization on total spectrum amplitude power and right occipital lateralization in Delta activity during waking. In contrast, during REM sleep, right frontal lateralization in Theta and Beta activities and right lateralization in occipital Delta activity was observed. These results suggest that spontaneous EEG activities generated during waking and REM sleep are supported in part by a common thalamo-cortical neural network (right occipital Delta dominance) while additional, possibly neuro-cognitive factors modulate waking left prefrontal dominance and REM sleep right frontal dominance.     

Perceived control effects on religiosity and quality of life among young adults

The study investigated the mediating role of perceived control in the association between religiosity and quality of life among young adults in south-west Nigeria. Data were collected from a sample of 1 050 young adults (mean age = 29.8, SD = 4.61; female = 38.7%). Regression analysis was utilised to predict quality of life from religiosity, partialling out perceived control. Findings suggest internal religiosity to predict an environmental domain of quality of life through perceived control. Perceived constraints appear to explain the association between internal religiosity and the environmental domain of quality of life.     

Brief reminiscence activities improve state well-being and self-concept in young adults: a randomised controlled experiment

Reminiscence-based psychotherapies have been demonstrated to have robust effects on a range of therapeutic outcomes. However, little research has been conducted on the immediate effects of guided activities they are composed of, or how these might differ dependent on the type of reminiscence. The current study utilised a controlled experimental design, whereby 321 young adults (mean age?=?25.5 years, SD?=?3.0) were randomised to one of four conditions of online reminiscence activity: problem-solving (successful coping experiences), identity (self-defining events contributing to a meaningful and continuous personal identity), bitterness revival (negative or adverse events), or a control condition (any memory from their past). Participants recalled autobiographical memories congruent with the condition, and answered questions to facilitate reflection on the memories. The results indicated that problem-solving and identity reminiscence activities caused significant improvements in self-esteem, meaning in life, self-efficacy and affect, whereas no effects were found in the bitterness revival and control conditions. Problem-solving reminiscence also caused a small effect in increasing perceptions of a life narrative/s. Differences between the conditions did not appear to be explained by the positive-valence of memories. These results provide evidence for the specific effects of adaptive types of problem-solving and identity reminiscence in young adults.     

Low diversity and low frequency of participation in leisure activities compromise working memory efficiency in young adults

People perform leisure activities (LA) every day; pursuits that entail applying cognitive, physical and social abilities. As in old age, doing LA during early and middle adulthood is related to a reduced risk of dementias, probably by generating a cognitive reserve. As it is possible that a relation between doing LA and working memory (WM) efficiency exists in young adults, we assessed whether the diversity and frequency of LA are related to WM efficiency in this population. Ninety-three healthy young subjects solved the n-back task at two levels of difficulty (2, 3), and answered an LA questionnaire on the activities in which they had participated in the month prior to the experiment. Subjects were classified separately on their scores for (1) diversity (high/low) and (2) frequency (high/low) in order to test the relation between each variable and WM efficiency. Though no differences were found, a subsequent analysis of the average of diversity and frequency ratios of LA performance taken together-the diversity/frequency index-showed that low diversity plus low frequency was significantly associated with reduced WM efficiency at this age; results that suggest that frequent participation in diverse LA during youth is related to WM efficiency.     

Comparison of Motionlogger Watch and Actiwatch actigraphs to polysomnography for sleep/wake estimation in healthy young adults

Sleep/wake identification and sleep parameter estimates from Motionlogger Watch and Actiwatch-64 actigraphs were compared to polysomnography (PSG). Following one night of baseline sleep, 29 volunteers remained awake for 36 h, followed by 11 h of recovery sleep in the laboratory. Two sets of analyses were performed: (1) epoch-by-epoch agreement and discriminability index (d') calculations, and (2) sleep parameter concordance with repeated measures ANOVAs. Sensitivity (sleep identification), specificity (wake detection), and overall agreement with PSG, as well as d', were higher for the Motionlogger than for Actiwatch. Relative to PSG, the Actiwatch-estimated total sleep time and sleep efficiency were underestimated and the number of awakenings was overestimated for baseline and recovery; sleep latency was underestimated on the baseline night. On the other hand, the Motionlogger-estimated total sleep time and sleep efficiency estimates were underestimated, and the sleep latency was overestimated on recovery, versus PSG. Despite these misestimations, it was concluded that the Motionlogger provided nominally better agreement with PSG, and that actigraphy generally constitutes a reasonably reliable tool for producing objective measurements of sleep/wake, but that users should remain mindful of its limitations.     

Sustained-attention capacity in young and older adults

The sustained-attention capacity of young (21-29 years) and older (65-78 years) adults was examined using a high-event rate digit-discrimination vigilance task presented at three levels of stimulus degradation. Increased stimulus degradation led to a reduction in the hit rate and to a greater decline in hit rate over blocks (increased vigilance decrement). Sensitivity (d') declined over blocks only at the highest level of stimulus degradation. Older adults had a lower hit rate and showed greater vigilance decrement than young adults, particularly when stimuli were highly degraded. However, both age groups showed the same pattern of stability in sensitivity when stimulus degradation was moderate, and sensitivity decrement over time when stimulus degradation was high. The results suggest that the process of sustained allocation of capacity--as reflected in temporal changes in sensitivity--operates similarly in young and older adults.     

Feature binding in children and young adults

The authors measured memory for individual features (objects only or locations only) and the combination of those features (objects and locations) in 9-, 12-, and 21-year-old students with a yes or no recognition task. Analysis of recognition memory performance (d' scores) revealed that although age differences existed in memory for individual features, age differences were greater in the tasks that required memory for combined features (objects and locations). Hierarchical multiple regression analyses indicated that age remained a significant predictor of memory performance in the combination condition even after the authors statistically removed memory performance in object and location conditions and the interaction effects of object and location. These results provide evidence for developmental differences in the binding of features in memory.     

Non-symbolic arithmetic in adults and young children

Five experiments investigated whether adults and preschool children can perform simple arithmetic calculations on non-symbolic numerosities. Previous research has demonstrated that human adults, human infants, and non-human animals can process numerical quantities through approximate representations of their magnitudes. Here we consider whether these non-symbolic numerical representations might serve as a building block of uniquely human, learned mathematics. Both adults and children with no training in arithmetic successfully performed approximate arithmetic on large sets of elements. Success at these tasks did not depend on non-numerical continuous quantities, modality-specific quantity information, the adoption of alternative non-arithmetic strategies, or learned symbolic arithmetic knowledge. Abstract numerical quantity representations therefore are computationally functional and may provide a foundation for formal mathematics.     

Subjective age and sleep in middle-aged and older adults

Objective: Chronological age is commonly used to explain change in sleep. The present study examines whether subjective age is associated with change in sleep difficulties across middle adulthood and old age.

Design: Participants were drawn from the second (2004–2005) and third (2013–2014) waves of the Midlife in the United States Survey (MIDUS, N = 2350; Mean Age: 55.54 years), the 2008 and 2014 waves of the Health and Retirement Study (HRS, N = 4066; Mean Age: 67.59 years) and the first (2011) and fourth (2014) waves of the National Health and Aging Trends Survey (NHATS, N = 3541; Mean Age: 76.46). In each sample, subjective age, sleep difficulties, depressive symptoms, anxiety and chronic conditions were assessed at baseline. Sleep difficulties was assessed again at follow-up.

Main outcome measures: Sleep difficulties.

Results: An older subjective age at baseline was related to an increase in sleep difficulties over time in the three samples, and was mediated, in part, through more depressive symptoms, anxiety and chronic conditions. Feeling older was associated with an increased likelihood of major sleeping difficulties at follow-up in the three samples.

Conclusion: Subjective age is a salient marker of individuals’ at risk for poor sleep quality, beyond chronological age.     

Daily well-being of older adults with friends and family

Family members are the major source of physical and emotional support for older adults, yet researchers suggest that friendships have a stronger bearing on subjective well-being. In this research we sought an explanation for this inconsistency in older adults' immediate experiences with friends. Retired adults provided self-reports on their subjective states at random moments during a typical week. Analyses of these reports confirmed the prediction that older adults have more favorable experiences with their friends than with family members. The difference is partly attributable to the greater frequency of active leisure activities with friends, but is also due to unique qualities of interactions with friends that facilitate transcendence of mundane daily realities. We propose that friends provide an immediate situation of openness, reciprocity, and positive feedback that engenders enjoyment and subjectively meaningful exchanges.     

Semantic satiation in healthy young and older adults

In four experiments, semantic satiation was investigated in young and old adults. In the first two experiments, subjects were repeatedly presented a word (e.g.,dog) and then were presented a pair of words (e.g.,dog-cat ordog-chair) for a relatedness decision. The results of both experiments indicated that for the young adults, the relatedness effect (the difference between response latency on related and unrelated trials) decreased as a function of the number of times the satiated word was repeated, whereas for the older adults, there was no evidence of a decrease in the relatedness effect across repetitions of the satiated word. In the third experiment, we investigated whether phonological codes are also susceptible to satiation. This experiment was similar to the first two experiments with the exception that subjects made rhyme decisions (same-claim vs.same-dime) instead of semantic relatedness decisions. The results of this experiment did not yield any evidence of satiation for either the young adults or the older adults. The final experiment eliminated a simple decrease in attentional alertness or fatigue account of the semantic satiation effects found in the first two experiments. In this experiment, the repeated word was always unrelated to the pair of words presented for the relatedness decision. The results of this experiment did not yield any evidence of semantic satiation for either the young or the older adults. The discussion focuses on the mechanisms underlying semantic satiation and the implications of age-related changes in these mechanisms.     

Executive process training in young and old adults

There is a growing body of research on the modifiability of executive functions in different stages of life. Previous studies demonstrate robust training effects but limited transfer in younger and particularly in older adults. The aim of the present study was to investigate whether a theoretically derived intervention for executive functioning, addressing several basic processes (updating, shifting, and inhibition), can induce transfer effects in early and late adulthood. Fifty-nine healthy adults, 29 young and 30 older adults, were randomly assigned to either training or no-contact control groups. The training groups received 15 sessions of executive process training for about 45 min/session during 5 weeks. A test battery including a criterion task and near, intermediate, and far transfer tasks was administered before and after training. Results showed pronounced age-equivalent gains on the criterion task. Near transfer was seen to non-trained updating and inhibition tasks for the young and older trained participants. However, only the young adults showed intermediate transfer to two complex working memory tasks. No far transfer effects were seen for either age group. These findings provide additional evidence for age-related constraints in the ability to generalize acquired executive skills, and specifically show that training of multiple executive processes is not sufficient to foster transfer beyond the very near in older adults.