Objective: Social isolation and loneliness are associated with poor health (immunity, inflammation, etc.) in ageing. The purpose of this scoping review was to investigate the link between social isolation, loneliness (as distinct constructs, in contrast to previous published work) and cognition in cognitively healthy older adults.Method: We followed PRISMA-ScR guidelines. Our search, conducted between January 2017 and April 2021, yielded 2,673 articles, of which, twelve longitudinal studies were finally identified as meeting the inclusion criteria. Multiple cognitive functions (short-term and episodic memory, attention, and global cognitive functioning) were measured.Results: The results showed that both social isolation and loneliness were associated with poor cognition in ageing, with depression as a possible mediator between loneliness and poor cognition. Some studies also suggested that the link between social isolation, loneliness and cognitive decline may be bidirectional.Conclusion: We conclude that both social isolation and loneliness may have a different impact on cognition. While depression may be an important mediator between loneliness and cognitive decline, the lack of cognitive stimulation may be a greater mediator between social isolation and cognitive health.

The authors explored the effect of age on executive functions by using 3 tasks (Tower of London, Hayling, and Brixton tests) designed to assess specific executive processes (planning, inhibition, and abstraction of logical rules) that were also sensitive to frontal dysfunction. The performance of elderly participants (n = 48) was significantly poorer than that of young participants (n = 47) in all 3 tasks. Processing speed, measured by means of a color-naming task, explained some but not all of the age-related differences. These results are discussed in terms of general and specific factors in cognitive aging.

One of the major accounts of cognitive aging states that age effects are related to a deficiency of inhibitory mechanisms ( Hasher & Zacks, 1988 Hasher, L. and Zacks, R. T. 1988. “Working memory, comprehension, and aging: A review and a new view”. In The psychology of learning and motivation, Edited by: Bower, G. H. Vol. 22, 193–225. Orlando, FL: Academic Press. [Crossref] [Google Scholar] ). Given that inhibition has traditionally been associated with the frontal cortex, and that the frontal cortex deteriorates early with age ( Raz, 2000 Raz, N. 2000. “Aging of the brain and its impact on cognitive performance: Integration of structural and functional findings”. In Handbook of aging and cognition–II, Edited by: Craik, F. I. M. and Salthouse, T. A. 1–90. Mahwah, N.J.: Erlbaum.. [Google Scholar] ), this is consistent with the frontal hypothesis of aging ( West, 1996 West, R. L. 1996. An application of prefrontal cortex function theory to cognitive aging. Psychological Bulletin, 120: 272–292. [Crossref], [PubMed], [Web of Science ®] [Google Scholar] ). However, not all inhibitory processes require executive control, and so they are not all equally supported by the frontal cortex. As a consequence, one would expect dissociations between inhibitory tasks in the sense of a greater susceptibility of executive/frontal inhibition to aging. Based on Nigg's (2000) Nigg, J. T. 2000. On inhibition/disinhibition in developmental psychopathology: Views from cognitive and personality psychology and a working inhibition taxonomy. Psychological Bulletin, 126: 200–246. [Google Scholar] working inhibition taxonomy, we tested this hypothesis by combining inhibitory paradigms with different levels of executive control within the same participants. The results showed that age affects Stroop interference but not negative priming (Experiment 1) and stop signal responsiveness but not negative priming (Experiment 2). These findings suggest that tasks with a high executive (or effortful) inhibitory control are more sensitive to aging than tasks with a lower executive (more automatic) inhibitory control. The results are discussed in relation to the inhibitory and frontal accounts of aging.

The present study examined the effects of mindfulness on depression and anxiety, both direct and indirect through the mediation of four mechanisms of emotional regulation: worry, rumination, reappraisal and suppression. Path analysis was applied to data collected from an international and non-clinical sample of 1151 adults, including both meditators and non-meditators, who completed an online questionnaire battery. Our results show that mindfulness are related to lower levels of depression and anxiety both directly and indirectly. Suppression, reappraisal, worry and rumination all acted as significant mediators of the relationship between mindfulness and depression. A similar picture emerged for the relationship between mindfulness and anxiety, with the difference that suppression was not a mediator. Our data also revealed that the estimated number of hours of mindfulness meditation practice did not affect depression or anxiety directly but did reduce these indirectly by increasing mindfulness. Worry and rumination proved to be the most potent mediating variables. Altogether, our results confirm that emotional regulation plays a significant mediating role between mindfulness and symptoms of depression and anxiety in the general population and suggest that meditation focusing on reducing worry and rumination may be especially useful in reducing the risk of developing clinical depression.