Age-Differential Role of Gaze Reinstatement in Recognition Memory for Negative Visual Stimuli.

OBJECTIVES: Although research has shown that the replay of encoding-specific gaze patterns during retrieval, known as gaze reinstatement, facilitates memory retrieval, little is known about whether it differentially associates with the negativity preference in memory (defined as enhanced memory for negative stimuli relative to neutral stimuli in this study) among younger and older adults. The present study aims to address this research gap. METHODS: A total of 33 older adults (16 women; aged 58-69 years, M = 63.48, SD = 2.98) and 36 younger adults (10 women; aged 18-26 years, M = 20.39, SD = 1.57) completed a remember/know recognition memory task involving negative and neutral pictures. Their eye movements were tracked during both the memory encoding and retrieval phases. RESULTS: Younger and older adults had better memory for negative than neutral pictures. Older adults exhibited significantly stronger gaze reinstatement for negative than neutral stimuli, while this difference was nonsignificant in younger adults. Moreover, gaze reinstatement is positively linked to memory performance in both age groups. DISCUSSION: The results suggest that gaze reinstatement may play age-differential roles in the negativity preference of memory. Negative valence may enhance gaze reinstatement, which improves subsequent recognition memory, particularly among older adults. The finding contributes to a better understanding of the mechanisms underlying the negative preference for memory in different age groups.

A self-supported sodium alginate composite hydrogel membrane and its performance in filtering heavy metal ions.

A novel self-supported polysaccharide based hydrogel membrane was prepared by adding cellulose nanofiber (CNF) and micron-sized biochar (BC) into sodium alginate (SA) hydrogel with in-situ free water evaporation ("cooking") process and ionic crosslinking, in which the polyethylene glycol (PEG) was used as a pore-forming agent. Herein, CNF can not only enhance the mechanical property of the matrix, but also assist the homogeneous dispersion of BC. As a result, the prepared membrane had a maximum tensile strength of up to 5.69 MPa, which was more than 2-3 times higher than the previously reported self-supported hydrogel membranes. The flux reached 61.5 Lm-2 h-1 under 0.35 MPa pressure, and the anti-fouling property was also excellent due to its hydrophilicity. In filtration tests, the rejection of Cr (III) and Cr (VI) of 50 mg/l could reach 96.8 % and 91.4 %, respectively. Moreover, the mechanism behind the exceptional high rejection for both cationic and anionic heavy metal was delineated.

Cognitive training modified age-related brain changes in older adults with subjective memory decline.

OBJECTIVES: Neuroimaging findings suggest that older adults with subjective memory decline (SMD) demonstrate some neurodegenerative brain changes and have high risk of developing dementia, but relatively little is known about the effectiveness of interventions for SMD. This study aimed to examine the effects of cognitive training on resting-state brain activity in SMD. METHOD: This study employed the amplitude of low frequency fluctuations (ALFF) and resting state functional connectivity (rs-FC) analyses. After baseline evaluations, participants were randomly allocated to the intervention and control group to receive a four-week cognitive training and lectures on health and aging, respectively. All participants were scanned before and after training with an interval of about three months. RESULTS: (1) Participants in the intervention group showed significant improvements on the Associative Learning Test (ALT) and the Digit Span Forward task compared to the control group; (2) ALFF in the occipital lobe for the control group increased significantly, while that for the intervention group remained the same; ALFF changes were negatively correlated with ALT performance in the control group; (3) The mean value of rs-FC for the intervention group decreased, while that for the control group showed a trend of increase; rs-FC changes were also negatively correlated with ALT performance in the control group. CONCLUSIONS: Resting-state brain activities in occipital region increased with aging. The cognitive training could counteract this brain function changes associated with aging or even reverse the changes. These findings provide new insights into the understanding of brain plasticity in posterior areas in SMD. TRIAL REGISTRATION: ChiCTR-IOR-15006165 in the Chinese Clinical Trial Registry.

Time Unpacking Effect on Intertemporal Decision-Making: Does the Effect Change With Choice Valence?

People often feel that a period of time becomes longer when it is described in more detail or cut into more segments, which is known as the time unpacking effect. The current study aims to unveil how time unpacking manipulation impacts intertemporal decision making and whether the gain-loss valence of choices moderates such impacts. We recruited 87 college students (54 female) and randomly assigned them to the experimental conditions to complete a series of intertemporal choice tasks. The subjective values of the delayed choices were calculated for each participant and then analyzed. The results showed that participants perceived longer time delays and higher subjective values on the delayed gains (but not losses) in the time unpacking conditions than in the time packing conditions. These results suggest that time unpacking manipulation not only impacts time perception but also other factors, which in turn, influence the valuation of delayed outcomes and thereby intertemporal choices. The results are discussed in comparison to previous studies to highlight the complexity of the mechanism underlying the effect of time unpacking on intertemporal decision making.

Social Support and the Incidence of Cognitive Impairment Among Older Adults in China: Findings From the Chinese Longitudinal Healthy Longevity Survey Study.

OBJECTIVE: Social support shows a protective effect against cognitive impairment in older adults. However, the longitudinal relationship between the distinct sources of social support and the incidence of cognitive impairment remains unclear. This study aims to investigate the association between different sources of social support and the incidence of cognitive impairment among older adults in China. METHOD: We used longitudinal data (2005-2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 2005-2014, mean follow-up years 5.32 ± 2.64). In total, 5897 participants (aged 81.7 ± 9.7 years, range 65-112 years, 49.0% male) were enrolled. Cognitive impairment was measured by the Mini-Mental State Examination (MMSE). Social support included support from family and friends (marital status; contacts with family and friends; children's visits; siblings' visits, sick care; money received from and money given to children) and the availability of support from social community (social service and social security). We calculated subdistribution hazard ratios (SHR) of cognitive impairment by establishing Cox regression models, adjusting for residence, gender, age, education, participation in physical exercise, activities of daily living, smoking, drinking, negative psychological well-being, baseline cognitive function, occupation, leisure activities, and diseases. RESULTS: During a 9-year follow-up, 1047 participants developed cognitive impairment. Participants who were married had a 16.0% lower risk of developing cognitive impairment compared to the widowed older adults after controlling for all covariates, but the protective effect of being married was no longer significant (p = 0.067) when additional adjustment was made for all types of social support. Children's visits were significantly associated with the risk of cognitive impairment after controlling for all types of social support and covariate variables (SHR = 0.808, 95% confidence interval, 0.669-0.975, p = 0.026). CONCLUSION: Children's visits were consistently associated with a lower incidence of cognitive impairment in Chinese older adults.